EPC changes for existing buildings - Revision history

Editor at 14:11, 5 September 2025

2025-09-05T14:11:39Z

← Older revision		Revision as of 14:11, 5 September 2025
Line 11:		Line 11:
	= Past criticism, future considerations =		= Past criticism, future considerations =

−	Because the methodology behind an EPC is a simplified estimate it has for some time faced criticisms regarding common inaccuracies, which have become more vocal as requirements have become more stringent. Studies have highlighted flaws such as mismeasured floor areas, poor fabric assumptions, occupant usage and so on, often leading to overestimations of energy use. Inaccuracies in the procedure itself can stem from these assumptions, outdated or simplified modelling software, incorrect data points, human error, behaviour-based variability, weather conditions, building changes over time, default U-values and so on.	+	Because the methodology behind an EPC is a simplified estimate it has for some time faced criticisms regarding common inaccuracies, which have become more vocal as requirements have become more stringent. Studies have highlighted flaws such as mismeasured floor areas, poor fabric assumptions, occupant usage and so on, often leading to overestimations of energy use. Inaccuracies in the procedure itself can stem from these assumptions, outdated or simplified modelling software, incorrect data points, human error, behaviour-based variability, weather conditions, building changes over time, default U-values and so on. See the article Are Energy Performance Certificates accurate?

	The requirements to hold an EPC have gradually changed over time. Initially, from 2008, EPCs became mandatory for all buildings being sold, built, or rented, and then from 2018, with the introduction of the minimum energy efficiency standard (MEES), a minimum EPC rating of 'E' was required for new tenancies. In 2020 this was then expanded to all existing tenancies, in effect meaning that from April 2023, landlord properties with ratings below 'E' could not legally be let. Whilst the new requirements covered much of the rental stock, a variety of exemptions were given for short-term lets, historic buildings, and so on.		The requirements to hold an EPC have gradually changed over time. Initially, from 2008, EPCs became mandatory for all buildings being sold, built, or rented, and then from 2018, with the introduction of the minimum energy efficiency standard (MEES), a minimum EPC rating of 'E' was required for new tenancies. In 2020 this was then expanded to all existing tenancies, in effect meaning that from April 2023, landlord properties with ratings below 'E' could not legally be let. Whilst the new requirements covered much of the rental stock, a variety of exemptions were given for short-term lets, historic buildings, and so on.

Editor at 07:36, 6 June 2025

2025-06-06T07:36:20Z

← Older revision		Revision as of 07:36, 6 June 2025
Line 80:		Line 80:
	* Approved document L.		* Approved document L.
	* Display energy certificate DEC.		* Display energy certificate DEC.
		+	* ECA urges Government to uphold 13.2 billion Warm Homes manifesto commitment.
	* Emission rates.		* Emission rates.
	* Energy performance certificate EPC.		* Energy performance certificate EPC.
Line 96:		Line 97:
	* Reduced Data Standard Assessment Procedure.		* Reduced Data Standard Assessment Procedure.
	* Retrofit.		* Retrofit.
		+	* The Warm Homes Plan and existing policies to help with energy bills.
		+	* Warm homes programme, Wales.
		+	* Warm Homes Skills Programme.

	[[Category:DCN_Commentary]] [[Category:DCN_Manual]] [[Category:DCN_News]] [[Category:DCN_Organisation]] [[Category:DCN_Policy]] [[Category:DCN_Software]] [[Category:DCN_Specification]] [[Category:DCN_Standard]] [[Category:News]] [[Category:Organisations]] [[Category:Publications_/_reports]] [[Category:Standards_/_measurements]] [[Category:Sustainability]] [[Category:Taxation]] [[Category:Products_/_components]] [[Category:Property_development]] [[Category:Public_procedures]] [[Category:Roles_/_services]]		[[Category:DCN_Commentary]] [[Category:DCN_Manual]] [[Category:DCN_News]] [[Category:DCN_Organisation]] [[Category:DCN_Policy]] [[Category:DCN_Software]] [[Category:DCN_Specification]] [[Category:DCN_Standard]] [[Category:News]] [[Category:Organisations]] [[Category:Publications_/_reports]] [[Category:Standards_/_measurements]] [[Category:Sustainability]] [[Category:Taxation]] [[Category:Products_/_components]] [[Category:Property_development]] [[Category:Public_procedures]] [[Category:Roles_/_services]]

Editor at 07:32, 6 June 2025

2025-06-06T07:32:56Z

← Older revision		Revision as of 07:32, 6 June 2025
Line 73:		Line 73:

	To find out more about possible sources of third-party funding to help meet the minimum energy efficiency standards, visit the [https://energy-efficient-home.campaign.gov.uk government energy-efficient home campaign website here.]		To find out more about possible sources of third-party funding to help meet the minimum energy efficiency standards, visit the [https://energy-efficient-home.campaign.gov.uk government energy-efficient home campaign website here.]
		+
		+	--[[User:Editor\|editor]]

	= Related articles on Designing Buildings =		= Related articles on Designing Buildings =

Editor at 07:32, 6 June 2025

2025-06-06T07:32:24Z

← Older revision		Revision as of 07:32, 6 June 2025
Line 72:		Line 72:
	If a landlord feels that they might be exempt from meeting a certain standard because they have spent up to the cap and not met the newer standard, again, this may have to be evidenced in order to apply for an exemption. Furthermore, the landlord will be required to [https://prsregister.beis.gov.uk/NdsBeisUi/used-service-before register an exemption on the government website here].		If a landlord feels that they might be exempt from meeting a certain standard because they have spent up to the cap and not met the newer standard, again, this may have to be evidenced in order to apply for an exemption. Furthermore, the landlord will be required to [https://prsregister.beis.gov.uk/NdsBeisUi/used-service-before register an exemption on the government website here].

−	To find out more about possible sources of third-party funding to help meet the minimum efficiency standards, visit the [https://energy-efficient-home.campaign.gov.uk government energy-efficient home campaign website here.]	+	To find out more about possible sources of third-party funding to help meet the minimum energy efficiency standards, visit the [https://energy-efficient-home.campaign.gov.uk government energy-efficient home campaign website here.]

	= Related articles on Designing Buildings =		= Related articles on Designing Buildings =

Editor at 07:31, 6 June 2025

2025-06-06T07:31:28Z

← Older revision		Revision as of 07:31, 6 June 2025
Line 72:		Line 72:
	If a landlord feels that they might be exempt from meeting a certain standard because they have spent up to the cap and not met the newer standard, again, this may have to be evidenced in order to apply for an exemption. Furthermore, the landlord will be required to [https://prsregister.beis.gov.uk/NdsBeisUi/used-service-before register an exemption on the government website here].		If a landlord feels that they might be exempt from meeting a certain standard because they have spent up to the cap and not met the newer standard, again, this may have to be evidenced in order to apply for an exemption. Furthermore, the landlord will be required to [https://prsregister.beis.gov.uk/NdsBeisUi/used-service-before register an exemption on the government website here].

−	To find out more about possible sources of third-party funding to help meet the minimum efficiency standards, visit the [[w/~~index.php?title=W~~/~~index~~.~~php%3Ftitle%3DW/index~~.~~php%3Ftitle%3DGovernment_energy_efficient_home_campaign_website%26action%3Dedit%26redlink%3D1%26action%3Dedit%26redlink%3D1&action=edit&redlink=1\|~~government energy-efficient home campaign website here]].	+	To find out more about possible sources of third-party funding to help meet the minimum efficiency standards, visit the [https://energy-efficient-home.campaign.gov.uk government energy-efficient home campaign website here.]

	= Related articles on Designing Buildings =		= Related articles on Designing Buildings =

Waggle at 07:17, 6 June 2025

2025-06-06T07:17:53Z

← Older revision		Revision as of 07:17, 6 June 2025
Line 62:		Line 62:
	** PV battery and PV diverters added		** PV battery and PV diverters added

−	= What does this mean for owners, landlords and ~~tennants~~? =	+	= What does this mean for owners, landlords and tenants? =

	Firstly, because of the higher level of detail captured by the new RdSAP model, assessors will most likely take longer to assess a property, input the data and create the certificate. This means it is most likely that the cost of generating an EPC will go up; currently costs can vary from around 60 to 120 pounds. This does, however, mean that for tenants in particular, the newer EPCs should be a truer reflection of the energy performance of a property.		Firstly, because of the higher level of detail captured by the new RdSAP model, assessors will most likely take longer to assess a property, input the data and create the certificate. This means it is most likely that the cost of generating an EPC will go up; currently costs can vary from around 60 to 120 pounds. This does, however, mean that for tenants in particular, the newer EPCs should be a truer reflection of the energy performance of a property.
Line 72:		Line 72:
	If a landlord feels that they might be exempt from meeting a certain standard because they have spent up to the cap and not met the newer standard, again, this may have to be evidenced in order to apply for an exemption. Furthermore, the landlord will be required to [https://prsregister.beis.gov.uk/NdsBeisUi/used-service-before register an exemption on the government website here].		If a landlord feels that they might be exempt from meeting a certain standard because they have spent up to the cap and not met the newer standard, again, this may have to be evidenced in order to apply for an exemption. Furthermore, the landlord will be required to [https://prsregister.beis.gov.uk/NdsBeisUi/used-service-before register an exemption on the government website here].

−	To find out more about possible sources of third-party funding to help meet the minimum efficiency standards, visit the [[w/index.php?title=W/index.php%3Ftitle%3DGovernment_energy_efficient_home_campaign_website%26action%3Dedit%26redlink%3D1&action=edit&redlink=1\|government energy-efficient home campaign website here]].	+	To find out more about possible sources of third-party funding to help meet the minimum efficiency standards, visit the [[w/index.php?title=W/index.php%3Ftitle%3DW/index.php%3Ftitle%3DGovernment_energy_efficient_home_campaign_website%26action%3Dedit%26redlink%3D1%26action%3Dedit%26redlink%3D1&action=edit&redlink=1\|government energy-efficient home campaign website here]].

	= Related articles on Designing Buildings =		= Related articles on Designing Buildings =

Designing Buildings at 05:30, 6 June 2025

2025-06-06T05:30:56Z

Editor at 16:31, 5 June 2025

2025-06-05T16:31:14Z

Editor at 16:27, 5 June 2025

2025-06-05T16:27:46Z

← Older revision		Revision as of 16:27, 5 June 2025
Line 60:		Line 60:
	= What does this mean for owners, landlords and tennants? =		= What does this mean for owners, landlords and tennants? =

−	= Related articles on Designing Buildings =	+	Firstly, because of the higher level of detail captured by the new RdSAP model, assessors will most likely take longer to assess a property, input the data and create the certificate. This means it is most likely that the cost of generating an EPC will go up; currently costs of an EPC can vary from around 60 to 120 pounds. This does, however, mean that for tenants in particular, the newer EPCs should be a truer reflection of the energy performance of a property.
		+
		+	Secondly, because the new model captures a greater level of detail, it is likely that owners and landlords may be required to evidence any upgrades that have been made for them to be incorporated into the EPC rating, rather than default values. For example, the performance of newer double-glazed windows versus older models or the installation of insulation that is not easily seen by an assessor.
		+
		+	It is worth noting, however, that under the current Minimum Energy Efficiency Standards (MEES), a spending of up to £3,500 (including VAT) might be expected on energy efficiency improvements to a property that is let in order to bring it above an EPC level E. In the future this level will increase to C and will also apply to short lets and historical buildings with the same spending cap, so it is worthwhile keeping a record of any energy efficiency improvements that are made and the costs for these anyway.
		+
		+	If a landlord feels that they might be exempt from meeting a certain standard because they have spent up to the cap and not met the newer standard, again, this may have to be evidenced in order to apply for an exemption. Furthermore, the landlord will be required to [https://prsregister.beis.gov.uk/NdsBeisUi/used-service-before register an exemption on the government website here]. To find out more about possible sources of third-party funding to help meet the minimum efficiency standards, visit the [[government_energy_efficient_home_campaign_website\|government energy-efficient home campaign website here]]. It is a legal requirement when selling or letting a property in the UK to have an EPC, with fines up to £5,000, potentially increasing to more in the future.
		+
		+	There are, though, numerous benefits of getting a new EPC, as it outlines steps to improve energy efficiency, including potential costs and savings over time, which in practical terms will lead to lower bills and a lower carbon footprint. Furthermore, it is likely that energy-efficient homes may qualify for lower mortgage rates or cashback offers through green mortgage deals, so long as there is a valid EPC. Finally, many of the upgrades that might be made are likely to improve the quality of the living area and the appeal of a property over the longer term.
		+
		+	== Related articles on Designing Buildings ==

	* Approved document L.		* Approved document L.
Line 81:		Line 91:
	* Retrofit.		* Retrofit.

−	[[Category:~~Articles_needing_more_work~~]]	+	[[Category:DCN_Commentary]] [[Category:DCN_Manual]] [[Category:DCN_News]] [[Category:DCN_Organisation]] [[Category:DCN_Policy]] [[Category:DCN_Software]] [[Category:DCN_Specification]] [[Category:DCN_Standard]] [[Category:News]] [[Category:Organisations]] [[Category:Publications_/_reports]] [[Category:Standards_/_measurements]] [[Category:Sustainability]] [[Category:Taxation]] [[Category:Products_/_components]] [[Category:Property_development]] [[Category:Public_procedures]] [[Category:Roles_/_services]]

Editor at 12:19, 5 June 2025

2025-06-05T12:19:11Z

← Older revision		Revision as of 05:30, 6 June 2025
Line 3:		Line 3:
	= Background =		= Background =

−	Energy Performance Certificates (EPCs) ~~are a mechanism to~~ rate the energy efficiency of both new and existing buildings and suggest improvements that could be made. Originally introduced ~~to the UK~~ in 2003 via an EU directive, EPCs aimed to standardise efficiency ratings, inspired by successful appliance energy labels that drove market innovation and led to stricter efficiency grading systems ~~over time~~.	+	Energy Performance Certificates (EPCs) rate the energy efficiency of both new and existing buildings and suggest improvements that could be made. Originally introduced in 2003 via an EU directive, EPCs aimed to standardise efficiency ratings, inspired by successful appliance energy labels that drove market innovation and led to stricter efficiency grading systems.

	EPCs set out the energy efficiency rating of a building from A (most efficient) to G (least efficient) and are valid for 10 years. The EPC contains information about a property’s energy use, typical energy costs and recommendations about how to reduce energy use and save money. The calculation methodology behind residential EPCs is known as the [https://www.gov.uk/guidance/standard-assessment-procedure Standard Assessment Procedure] (SAP), with a slight variation known as the Reduced Standard Assessment Procedure (RdSAP), which is used for existing residential buildings.		EPCs set out the energy efficiency rating of a building from A (most efficient) to G (least efficient) and are valid for 10 years. The EPC contains information about a property’s energy use, typical energy costs and recommendations about how to reduce energy use and save money. The calculation methodology behind residential EPCs is known as the [https://www.gov.uk/guidance/standard-assessment-procedure Standard Assessment Procedure] (SAP), with a slight variation known as the Reduced Standard Assessment Procedure (RdSAP), which is used for existing residential buildings.

−	For buildings other than dwellings, the National Calculation Method (NCM) is used, which is based on the Simplified Building Energy Model (SBEM), the equivalent of SAP but with a number of differences. Both SAP and SBEM are energy estimating tools rather than actual energy measurement tools. In the case of some public buildings there is also a requirement to use and display a measured energy rating tool based on a yearly assessment; this is called the Display Energy Certificate (DEC)~~. Note that the graphics of a DEC look very similar to that of an EPC once complete, but the methodology behind them is very different, as DEC is a measured rating, whereas EPC is estimated~~.	+	For buildings other than dwellings, the National Calculation Method (NCM) is used, which is based on the Simplified Building Energy Model (SBEM), the equivalent of SAP but with a number of differences. Both SAP and SBEM are energy estimating tools rather than actual energy measurement tools. In the case of some public buildings there is also a requirement to use and display a measured energy rating tool based on a yearly assessment; this is called the Display Energy Certificate (DEC).

	= Past criticism, future considerations =		= Past criticism, future considerations =

−	Because the methodology behind an EPC is a simplified estimate it has for some time faced ~~criticism~~ regarding common inaccuracies, which have become more vocal as requirements have become more stringent. Studies have ~~in the past~~ highlighted flaws such as mismeasured floor areas, poor fabric assumptions, occupant usage and so ~~forth~~, often leading to overestimations of energy use. Inaccuracies in the procedure itself can stem from these assumptions, outdated or simplified modelling software, incorrect data points, human error, behaviour-based variability, weather conditions, building changes over time, default U-values and so on.	+	Because the methodology behind an EPC is a simplified estimate it has for some time faced criticisms regarding common inaccuracies, which have become more vocal as requirements have become more stringent. Studies have highlighted flaws such as mismeasured floor areas, poor fabric assumptions, occupant usage and so on, often leading to overestimations of energy use. Inaccuracies in the procedure itself can stem from these assumptions, outdated or simplified modelling software, incorrect data points, human error, behaviour-based variability, weather conditions, building changes over time, default U-values and so on.

−	The requirements to hold an EPC have gradually changed over time. Initially, from 2008, EPCs became mandatory for all buildings being sold, built, or rented, and then from 2018, with the introduction of the minimum energy efficiency standard (MEES), a minimum EPC rating of 'E' was required for new tenancies. In 2020 this was then expanded to all existing tenancies, in effect meaning that from April 2023, landlord properties with ratings below 'E' could not legally be let. Whilst the new requirements covered much of the rental stock, a variety of exemptions were given for short-term lets, ~~historical~~ buildings, and so forth. In February 2024 the Building Research Establishment (BRE) published a specification for its RdSAP, whilst the government published a number of consultations regarding MEES and EPCs, reviewing both the methodologies and the requirements for these.	+	The requirements to hold an EPC have gradually changed over time. Initially, from 2008, EPCs became mandatory for all buildings being sold, built, or rented, and then from 2018, with the introduction of the minimum energy efficiency standard (MEES), a minimum EPC rating of 'E' was required for new tenancies. In 2020 this was then expanded to all existing tenancies, in effect meaning that from April 2023, landlord properties with ratings below 'E' could not legally be let. Whilst the new requirements covered much of the rental stock, a variety of exemptions were given for short-term lets, historic buildings, and so on.

−	The current government proposal is to raise the minimum EPC rating to 'C' for new tenancies by 2025 and then for all tenancies by 2028, and alongside this, change the process by which exemptions apply. Whereas currently certain properties default to having an exemption, the new regime will have the default of applying to all properties, including short-term lets~~, historical~~ buildings ~~and so forth~~. Whilst certain exemptions will continue to exist, they will need to be applied for, evidenced and recorded on a register, with aspects such as the amount of money spent on energy efficiency improvements being considered.	+	In February 2024 the Building Research Establishment (BRE) published a specification for its RdSAP, whilst the government published a number of consultations regarding MEES and EPCs, reviewing both the methodologies and the requirements for these.
		+
		+	The current government proposal is to raise the minimum EPC rating to 'C' for new tenancies by 2025 and then for all tenancies by 2028, and alongside this, change the process by which exemptions apply. Whereas currently certain properties default to having an exemption, the new regime will have the default of applying to all properties, including short-term lets and historic buildings. Whilst certain exemptions will continue to exist, they will need to be applied for, evidenced and recorded on a register, with aspects such as the amount of money spent on energy efficiency improvements being considered.

	= Updated methodology =		= Updated methodology =

−	The methodology to calculate the EPC rating level of new buildings has been updated at various points ~~in time~~, with the latest version of SAP, SAP 10.2, including many more data points than were originally considered. The methodology used to calculate the EPC of existing buildings, RdSAP, although updated regularly, has largely remained the same, [https://files.bregroup.com/sap/Rdhttps://files.bregroup.com/sap/RdSAP_2012_9.94-20-09-2019.pdf?_its=JTdCJTIydmlkJTIyJTNBJTIyMzU1NzQxNWQtNjllZi00NDIwLWIxNjktZjE3OTZiOTExMDM0JTIyJTJDJTIyc3RhdGUlMjIlM0ElMjJybHR%2BMTY5Nzc5OTUzOH5sYW5kfjJfNzc4NzZfdnJlZl8wMmUzMzYxZjExOTgyNDM4MmIwNmIzY2FkN2M0ZWNiZSUyMiUyQyUyMnNpdGVJZCUyMiUzQTk4MDAlN0Q%3DSAP_2012_9.94-20-09-2019.pdf?_its=JTdCJTIydmlkJTIyJTNBJTIyMzU1NzQxNWQtNjllZi00NDIwLWIxNjktZjE3OTZiOTExMDM0JTIyJTJDJTIyc3RhdGUlMjIlM0ElMjJybHR%2BMTY5Nzc5OTUzOH5sYW5kfjJfNzc4NzZfdnJlZl8wMmUzMzYxZjExOTgyNDM4MmIwNmIzY2FkN2M0ZWNiZSUyMiUyQyUyMnNpdGVJZCUyMiUzQTk4MDAlN0Q%3D RdSAP] [https://files.bregroup.com/sap/Rdhttps://files.bregroup.com/sap/RdSAP_2012_9.94-20-09-2019.pdf?_its=JTdCJTIydmlkJTIyJTNBJTIyMzU1NzQxNWQtNjllZi00NDIwLWIxNjktZjE3OTZiOTExMDM0JTIyJTJDJTIyc3RhdGUlMjIlM0ElMjJybHR%2BMTY5Nzc5OTUzOH5sYW5kfjJfNzc4NzZfdnJlZl8wMmUzMzYxZjExOTgyNDM4MmIwNmIzY2FkN2M0ZWNiZSUyMiUyQyUyMnNpdGVJZCUyMiUzQTk4MDAlN0Q%3DSAP_2012_9.94-20-09-2019.pdf?_its=JTdCJTIydmlkJTIyJTNBJTIyMzU1NzQxNWQtNjllZi00NDIwLWIxNjktZjE3OTZiOTExMDM0JTIyJTJDJTIyc3RhdGUlMjIlM0ElMjJybHR%2BMTY5Nzc5OTUzOH5sYW5kfjJfNzc4NzZfdnJlZl8wMmUzMzYxZjExOTgyNDM4MmIwNmIzY2FkN2M0ZWNiZSUyMiUyQyUyMnNpdGVJZCUyMiUzQTk4MDAlN0Q%3D v9.94]. However, in February 2024, BRE published the [https://files.bregroup.com/SAP/RdSAP10-dt13.02.2024.pdf specification for the new updated RdSAP10], promising to be a much more detailed calculation of energy performance, helping to produce significantly more accurate EPCs for existing buildings. The specification brings the SAP approach for existing dwellings much closer to the approach that is used for new buildings~~, as the most significant update to the RdSAP in some 10 years; it hopes to resolve many of the criticisms previously held~~.	+	The methodology to calculate the EPC rating level of new buildings has been updated at various points, with the latest version of SAP, SAP 10.2, including many more data points than were originally considered. The methodology used to calculate the EPC of existing buildings, RdSAP, although updated regularly, has largely remained the same, [https://files.bregroup.com/sap/Rdhttps://files.bregroup.com/sap/RdSAP_2012_9.94-20-09-2019.pdf?_its=JTdCJTIydmlkJTIyJTNBJTIyMzU1NzQxNWQtNjllZi00NDIwLWIxNjktZjE3OTZiOTExMDM0JTIyJTJDJTIyc3RhdGUlMjIlM0ElMjJybHR%2BMTY5Nzc5OTUzOH5sYW5kfjJfNzc4NzZfdnJlZl8wMmUzMzYxZjExOTgyNDM4MmIwNmIzY2FkN2M0ZWNiZSUyMiUyQyUyMnNpdGVJZCUyMiUzQTk4MDAlN0Q%3DSAP_2012_9.94-20-09-2019.pdf?_its=JTdCJTIydmlkJTIyJTNBJTIyMzU1NzQxNWQtNjllZi00NDIwLWIxNjktZjE3OTZiOTExMDM0JTIyJTJDJTIyc3RhdGUlMjIlM0ElMjJybHR%2BMTY5Nzc5OTUzOH5sYW5kfjJfNzc4NzZfdnJlZl8wMmUzMzYxZjExOTgyNDM4MmIwNmIzY2FkN2M0ZWNiZSUyMiUyQyUyMnNpdGVJZCUyMiUzQTk4MDAlN0Q%3D RdSAP] [https://files.bregroup.com/sap/Rdhttps://files.bregroup.com/sap/RdSAP_2012_9.94-20-09-2019.pdf?_its=JTdCJTIydmlkJTIyJTNBJTIyMzU1NzQxNWQtNjllZi00NDIwLWIxNjktZjE3OTZiOTExMDM0JTIyJTJDJTIyc3RhdGUlMjIlM0ElMjJybHR%2BMTY5Nzc5OTUzOH5sYW5kfjJfNzc4NzZfdnJlZl8wMmUzMzYxZjExOTgyNDM4MmIwNmIzY2FkN2M0ZWNiZSUyMiUyQyUyMnNpdGVJZCUyMiUzQTk4MDAlN0Q%3DSAP_2012_9.94-20-09-2019.pdf?_its=JTdCJTIydmlkJTIyJTNBJTIyMzU1NzQxNWQtNjllZi00NDIwLWIxNjktZjE3OTZiOTExMDM0JTIyJTJDJTIyc3RhdGUlMjIlM0ElMjJybHR%2BMTY5Nzc5OTUzOH5sYW5kfjJfNzc4NzZfdnJlZl8wMmUzMzYxZjExOTgyNDM4MmIwNmIzY2FkN2M0ZWNiZSUyMiUyQyUyMnNpdGVJZCUyMiUzQTk4MDAlN0Q%3D v9.94]. However, in February 2024, BRE published the [https://files.bregroup.com/SAP/RdSAP10-dt13.02.2024.pdf specification for the new updated RdSAP10], promising to be a much more detailed calculation of energy performance, helping to produce significantly more accurate EPCs for existing buildings. The specification brings the SAP approach for existing dwellings much closer to the approach that is used for new buildings.

−	The new RdSAP specification has been developed by BRE on behalf of the government for use in existing dwellings based on a site assessment of the property when the complete ~~data set~~ for SAP calculation is not available. The RdSAP calculation starting from reduced data is done in two stages. First the collected data (reduced data set) is expanded into a full data set, and then the SAP calculation is undertaken using the expanded data set. The SAP calculation is therefore identical, whether starting from a reduced data set or a full data set. This version of RdSAP forms part of the SAP 10.2 specification and provides a data input set for use with version 10.2 of SAP.	+	The new RdSAP specification has been developed by BRE on behalf of the government for use in existing dwellings based on a site assessment of the property when the complete dataset for SAP calculation is not available. The RdSAP calculation, starting from reduced data, is done in two stages. First the collected data (reduced data set) is expanded into a full data set, and then the SAP calculation is undertaken using the expanded data set. The SAP calculation is therefore identical, whether starting from a reduced data set or a full data set. This version of RdSAP forms part of the SAP 10.2 specification and provides a data input set for use with version 10.2 of SAP.

	BRE state that there are significant changes in RdSAP 10 when compared to the RdSAP 2012 specification, and these include:		BRE state that there are significant changes in RdSAP 10 when compared to the RdSAP 2012 specification, and these include:
Line 62:		Line 64:
	= What does this mean for owners, landlords and tennants? =		= What does this mean for owners, landlords and tennants? =

−	Firstly, because of the higher level of detail captured by the new RdSAP model, assessors will most likely take longer to assess a property, input the data and create the certificate. This means it is most likely that the cost of generating an EPC will go up; currently costs ~~of an EPC~~ can vary from around 60 to 120 pounds. This does, however, mean that for tenants in particular, the newer EPCs should be a truer reflection of the energy performance of a property.	+	Firstly, because of the higher level of detail captured by the new RdSAP model, assessors will most likely take longer to assess a property, input the data and create the certificate. This means it is most likely that the cost of generating an EPC will go up; currently costs can vary from around 60 to 120 pounds. This does, however, mean that for tenants in particular, the newer EPCs should be a truer reflection of the energy performance of a property.

−	Secondly, because the new model captures a greater level of detail, it is likely that owners and landlords may be required to evidence any upgrades that have been made for them to be incorporated into the EPC rating, rather than default values. For example, the performance of newer double-glazed windows versus older models or the installation of insulation that is not easily seen by an assessor.	+	Secondly, because the new model captures a greater level of detail, it is likely that owners and landlords may be required to evidence any upgrades that have been made for them to be incorporated into the EPC rating, rather than using default values. For example, the performance of newer double-glazed windows versus older models or the installation of insulation that is not easily seen by an assessor.

−	It is worth noting, however, that under the current Minimum Energy Efficiency Standards (MEES), a spending of up to £3,500 (including VAT) might be expected on energy efficiency improvements to a property that is let in order to bring it above an EPC level E. In the future this level will increase to C and will also apply to short lets and ~~historical~~ buildings with the same spending cap, so it is worthwhile keeping a record of any energy efficiency improvements that are made and the costs ~~for these anyway~~.	+	It is worth noting however, that under the current Minimum Energy Efficiency Standards (MEES), a spending of up to £3,500 (including VAT) might be expected on energy efficiency improvements to a property that is let in order to bring it above an EPC level E. In the future this level will increase to C and will also apply to short lets and historic buildings with the same spending cap, so it is worthwhile keeping a record of any energy efficiency improvements that are made and the costs.

−	If a landlord feels that they might be exempt from meeting a certain standard because they have spent up to the cap and not met the newer standard, again, this may have to be evidenced in order to apply for an exemption. Furthermore, the landlord will be required to [https://prsregister.beis.gov.uk/NdsBeisUi/used-service-before register an exemption on the government website here]. To find out more about possible sources of third-party funding to help meet the minimum efficiency standards, visit the [[w/index.php?title=Government_energy_efficient_home_campaign_website&action=edit&redlink=1\|government energy-efficient home campaign website here]]. It is a legal requirement when selling or letting a property in the UK to have an EPC, with fines up to £5,000, potentially increasing to more in the future.	+	If a landlord feels that they might be exempt from meeting a certain standard because they have spent up to the cap and not met the newer standard, again, this may have to be evidenced in order to apply for an exemption. Furthermore, the landlord will be required to [https://prsregister.beis.gov.uk/NdsBeisUi/used-service-before register an exemption on the government website here].

−	~~There are, though, numerous benefits~~ of ~~getting a new EPC, as it outlines steps~~ to ~~improve energy~~ efficiency, ~~including potential costs and savings over time, which in practical terms will lead to lower bills and a lower carbon footprint~~. ~~Furthermore, it is likely that~~ energy-efficient homes may qualify for lower mortgage rates or cashback offers through green mortgage deals, so long as there is a valid EPC. Finally, many of the upgrades that might be made are likely to improve the quality of the living area and the appeal of a property over the longer term.	+	To find out more about possible sources of third-party funding to help meet the minimum efficiency standards, visit the [[w/index.php?title=W/index.php%3Ftitle%3DGovernment_energy_efficient_home_campaign_website%26action%3Dedit%26redlink%3D1&action=edit&redlink=1\|government energy-efficient home campaign website here]].

−	== Related articles on Designing Buildings ==	+	= Related articles on Designing Buildings =

	* Approved document L.		* Approved document L.

← Older revision		Revision as of 16:31, 5 June 2025
Line 5:		Line 5:
	Energy Performance Certificates (EPCs) are a mechanism to rate the energy efficiency of both new and existing buildings and suggest improvements that could be made. Originally introduced to the UK in 2003 via an EU directive, EPCs aimed to standardise efficiency ratings, inspired by successful appliance energy labels that drove market innovation and led to stricter efficiency grading systems over time.		Energy Performance Certificates (EPCs) are a mechanism to rate the energy efficiency of both new and existing buildings and suggest improvements that could be made. Originally introduced to the UK in 2003 via an EU directive, EPCs aimed to standardise efficiency ratings, inspired by successful appliance energy labels that drove market innovation and led to stricter efficiency grading systems over time.

−	EPCs set out the energy efficiency rating of a building from A (most efficient) to G (least efficient) and are valid for 10 years. The EPC contains information about a property’s energy use, typical energy costs and recommendations about how to reduce energy use and save money. The calculation methodology behind residential EPCs is known as the Standard Assessment Procedure (SAP), with a slight variation known as the Reduced Standard Assessment Procedure (RdSAP), which is used for existing residential buildings.	+	EPCs set out the energy efficiency rating of a building from A (most efficient) to G (least efficient) and are valid for 10 years. The EPC contains information about a property’s energy use, typical energy costs and recommendations about how to reduce energy use and save money. The calculation methodology behind residential EPCs is known as the [https://www.gov.uk/guidance/standard-assessment-procedure Standard Assessment Procedure] (SAP), with a slight variation known as the Reduced Standard Assessment Procedure (RdSAP), which is used for existing residential buildings.

	For buildings other than dwellings, the National Calculation Method (NCM) is used, which is based on the Simplified Building Energy Model (SBEM), the equivalent of SAP but with a number of differences. Both SAP and SBEM are energy estimating tools rather than actual energy measurement tools. In the case of some public buildings there is also a requirement to use and display a measured energy rating tool based on a yearly assessment; this is called the Display Energy Certificate (DEC). Note that the graphics of a DEC look very similar to that of an EPC once complete, but the methodology behind them is very different, as DEC is a measured rating, whereas EPC is estimated.		For buildings other than dwellings, the National Calculation Method (NCM) is used, which is based on the Simplified Building Energy Model (SBEM), the equivalent of SAP but with a number of differences. Both SAP and SBEM are energy estimating tools rather than actual energy measurement tools. In the case of some public buildings there is also a requirement to use and display a measured energy rating tool based on a yearly assessment; this is called the Display Energy Certificate (DEC). Note that the graphics of a DEC look very similar to that of an EPC once complete, but the methodology behind them is very different, as DEC is a measured rating, whereas EPC is estimated.
		+
		+	= Past criticism, future considerations =

	Because the methodology behind an EPC is a simplified estimate it has for some time faced criticism regarding common inaccuracies, which have become more vocal as requirements have become more stringent. Studies have in the past highlighted flaws such as mismeasured floor areas, poor fabric assumptions, occupant usage and so forth, often leading to overestimations of energy use. Inaccuracies in the procedure itself can stem from these assumptions, outdated or simplified modelling software, incorrect data points, human error, behaviour-based variability, weather conditions, building changes over time, default U-values and so on.		Because the methodology behind an EPC is a simplified estimate it has for some time faced criticism regarding common inaccuracies, which have become more vocal as requirements have become more stringent. Studies have in the past highlighted flaws such as mismeasured floor areas, poor fabric assumptions, occupant usage and so forth, often leading to overestimations of energy use. Inaccuracies in the procedure itself can stem from these assumptions, outdated or simplified modelling software, incorrect data points, human error, behaviour-based variability, weather conditions, building changes over time, default U-values and so on.
Line 17:		Line 19:
	= Updated methodology =		= Updated methodology =

−	The methodology to calculate the EPC rating level of new buildings has been updated at various points in time, with the latest version of SAP, SAP 10.2, including many more data points than were originally considered. The methodology used to calculate the EPC of existing buildings, RdSAP, although updated regularly, has largely remained the same, [https://files.bregroup.com/sap/Rdhttps://files.bregroup.com/sap/RdSAP_2012_9.94-20-09-2019.pdf?_its=JTdCJTIydmlkJTIyJTNBJTIyMzU1NzQxNWQtNjllZi00NDIwLWIxNjktZjE3OTZiOTExMDM0JTIyJTJDJTIyc3RhdGUlMjIlM0ElMjJybHR%2BMTY5Nzc5OTUzOH5sYW5kfjJfNzc4NzZfdnJlZl8wMmUzMzYxZjExOTgyNDM4MmIwNmIzY2FkN2M0ZWNiZSUyMiUyQyUyMnNpdGVJZCUyMiUzQTk4MDAlN0Q%3DSAP_2012_9.94-20-09-2019.pdf?_its=JTdCJTIydmlkJTIyJTNBJTIyMzU1NzQxNWQtNjllZi00NDIwLWIxNjktZjE3OTZiOTExMDM0JTIyJTJDJTIyc3RhdGUlMjIlM0ElMjJybHR%2BMTY5Nzc5OTUzOH5sYW5kfjJfNzc4NzZfdnJlZl8wMmUzMzYxZjExOTgyNDM4MmIwNmIzY2FkN2M0ZWNiZSUyMiUyQyUyMnNpdGVJZCUyMiUzQTk4MDAlN0Q%3D RdSAP] [https://files.bregroup.com/sap/Rdhttps://files.bregroup.com/sap/RdSAP_2012_9.94-20-09-2019.pdf?_its=JTdCJTIydmlkJTIyJTNBJTIyMzU1NzQxNWQtNjllZi00NDIwLWIxNjktZjE3OTZiOTExMDM0JTIyJTJDJTIyc3RhdGUlMjIlM0ElMjJybHR%2BMTY5Nzc5OTUzOH5sYW5kfjJfNzc4NzZfdnJlZl8wMmUzMzYxZjExOTgyNDM4MmIwNmIzY2FkN2M0ZWNiZSUyMiUyQyUyMnNpdGVJZCUyMiUzQTk4MDAlN0Q%3DSAP_2012_9.94-20-09-2019.pdf?_its=JTdCJTIydmlkJTIyJTNBJTIyMzU1NzQxNWQtNjllZi00NDIwLWIxNjktZjE3OTZiOTExMDM0JTIyJTJDJTIyc3RhdGUlMjIlM0ElMjJybHR%2BMTY5Nzc5OTUzOH5sYW5kfjJfNzc4NzZfdnJlZl8wMmUzMzYxZjExOTgyNDM4MmIwNmIzY2FkN2M0ZWNiZSUyMiUyQyUyMnNpdGVJZCUyMiUzQTk4MDAlN0Q%3D v9.94]. However, in February 2024, BRE published the specification for the new updated RdSAP10, promising to be a much more detailed calculation of energy performance, helping to produce significantly more accurate EPCs for existing buildings. The specification brings the SAP approach for existing dwellings much closer to the approach that is used for new buildings, as the most significant update to the RdSAP in some 10 years; it hopes to resolve many of the criticisms previously held.	+	The methodology to calculate the EPC rating level of new buildings has been updated at various points in time, with the latest version of SAP, SAP 10.2, including many more data points than were originally considered. The methodology used to calculate the EPC of existing buildings, RdSAP, although updated regularly, has largely remained the same, [https://files.bregroup.com/sap/Rdhttps://files.bregroup.com/sap/RdSAP_2012_9.94-20-09-2019.pdf?_its=JTdCJTIydmlkJTIyJTNBJTIyMzU1NzQxNWQtNjllZi00NDIwLWIxNjktZjE3OTZiOTExMDM0JTIyJTJDJTIyc3RhdGUlMjIlM0ElMjJybHR%2BMTY5Nzc5OTUzOH5sYW5kfjJfNzc4NzZfdnJlZl8wMmUzMzYxZjExOTgyNDM4MmIwNmIzY2FkN2M0ZWNiZSUyMiUyQyUyMnNpdGVJZCUyMiUzQTk4MDAlN0Q%3DSAP_2012_9.94-20-09-2019.pdf?_its=JTdCJTIydmlkJTIyJTNBJTIyMzU1NzQxNWQtNjllZi00NDIwLWIxNjktZjE3OTZiOTExMDM0JTIyJTJDJTIyc3RhdGUlMjIlM0ElMjJybHR%2BMTY5Nzc5OTUzOH5sYW5kfjJfNzc4NzZfdnJlZl8wMmUzMzYxZjExOTgyNDM4MmIwNmIzY2FkN2M0ZWNiZSUyMiUyQyUyMnNpdGVJZCUyMiUzQTk4MDAlN0Q%3D RdSAP] [https://files.bregroup.com/sap/Rdhttps://files.bregroup.com/sap/RdSAP_2012_9.94-20-09-2019.pdf?_its=JTdCJTIydmlkJTIyJTNBJTIyMzU1NzQxNWQtNjllZi00NDIwLWIxNjktZjE3OTZiOTExMDM0JTIyJTJDJTIyc3RhdGUlMjIlM0ElMjJybHR%2BMTY5Nzc5OTUzOH5sYW5kfjJfNzc4NzZfdnJlZl8wMmUzMzYxZjExOTgyNDM4MmIwNmIzY2FkN2M0ZWNiZSUyMiUyQyUyMnNpdGVJZCUyMiUzQTk4MDAlN0Q%3DSAP_2012_9.94-20-09-2019.pdf?_its=JTdCJTIydmlkJTIyJTNBJTIyMzU1NzQxNWQtNjllZi00NDIwLWIxNjktZjE3OTZiOTExMDM0JTIyJTJDJTIyc3RhdGUlMjIlM0ElMjJybHR%2BMTY5Nzc5OTUzOH5sYW5kfjJfNzc4NzZfdnJlZl8wMmUzMzYxZjExOTgyNDM4MmIwNmIzY2FkN2M0ZWNiZSUyMiUyQyUyMnNpdGVJZCUyMiUzQTk4MDAlN0Q%3D v9.94]. However, in February 2024, BRE published the [https://files.bregroup.com/SAP/RdSAP10-dt13.02.2024.pdf specification for the new updated RdSAP10], promising to be a much more detailed calculation of energy performance, helping to produce significantly more accurate EPCs for existing buildings. The specification brings the SAP approach for existing dwellings much closer to the approach that is used for new buildings, as the most significant update to the RdSAP in some 10 years; it hopes to resolve many of the criticisms previously held.

	The new RdSAP specification has been developed by BRE on behalf of the government for use in existing dwellings based on a site assessment of the property when the complete data set for SAP calculation is not available. The RdSAP calculation starting from reduced data is done in two stages. First the collected data (reduced data set) is expanded into a full data set, and then the SAP calculation is undertaken using the expanded data set. The SAP calculation is therefore identical, whether starting from a reduced data set or a full data set. This version of RdSAP forms part of the SAP 10.2 specification and provides a data input set for use with version 10.2 of SAP.		The new RdSAP specification has been developed by BRE on behalf of the government for use in existing dwellings based on a site assessment of the property when the complete data set for SAP calculation is not available. The RdSAP calculation starting from reduced data is done in two stages. First the collected data (reduced data set) is expanded into a full data set, and then the SAP calculation is undertaken using the expanded data set. The SAP calculation is therefore identical, whether starting from a reduced data set or a full data set. This version of RdSAP forms part of the SAP 10.2 specification and provides a data input set for use with version 10.2 of SAP.
Line 66:		Line 68:
	It is worth noting, however, that under the current Minimum Energy Efficiency Standards (MEES), a spending of up to £3,500 (including VAT) might be expected on energy efficiency improvements to a property that is let in order to bring it above an EPC level E. In the future this level will increase to C and will also apply to short lets and historical buildings with the same spending cap, so it is worthwhile keeping a record of any energy efficiency improvements that are made and the costs for these anyway.		It is worth noting, however, that under the current Minimum Energy Efficiency Standards (MEES), a spending of up to £3,500 (including VAT) might be expected on energy efficiency improvements to a property that is let in order to bring it above an EPC level E. In the future this level will increase to C and will also apply to short lets and historical buildings with the same spending cap, so it is worthwhile keeping a record of any energy efficiency improvements that are made and the costs for these anyway.

−	If a landlord feels that they might be exempt from meeting a certain standard because they have spent up to the cap and not met the newer standard, again, this may have to be evidenced in order to apply for an exemption. Furthermore, the landlord will be required to [https://prsregister.beis.gov.uk/NdsBeisUi/used-service-before register an exemption on the government website here]. To find out more about possible sources of third-party funding to help meet the minimum efficiency standards, visit the [[~~government_energy_efficient_home_campaign_website~~\|government energy-efficient home campaign website here]]. It is a legal requirement when selling or letting a property in the UK to have an EPC, with fines up to £5,000, potentially increasing to more in the future.	+	If a landlord feels that they might be exempt from meeting a certain standard because they have spent up to the cap and not met the newer standard, again, this may have to be evidenced in order to apply for an exemption. Furthermore, the landlord will be required to [https://prsregister.beis.gov.uk/NdsBeisUi/used-service-before register an exemption on the government website here]. To find out more about possible sources of third-party funding to help meet the minimum efficiency standards, visit the [[w/index.php?title=Government_energy_efficient_home_campaign_website&action=edit&redlink=1\|government energy-efficient home campaign website here]]. It is a legal requirement when selling or letting a property in the UK to have an EPC, with fines up to £5,000, potentially increasing to more in the future.

	There are, though, numerous benefits of getting a new EPC, as it outlines steps to improve energy efficiency, including potential costs and savings over time, which in practical terms will lead to lower bills and a lower carbon footprint. Furthermore, it is likely that energy-efficient homes may qualify for lower mortgage rates or cashback offers through green mortgage deals, so long as there is a valid EPC. Finally, many of the upgrades that might be made are likely to improve the quality of the living area and the appeal of a property over the longer term.		There are, though, numerous benefits of getting a new EPC, as it outlines steps to improve energy efficiency, including potential costs and savings over time, which in practical terms will lead to lower bills and a lower carbon footprint. Furthermore, it is likely that energy-efficient homes may qualify for lower mortgage rates or cashback offers through green mortgage deals, so long as there is a valid EPC. Finally, many of the upgrades that might be made are likely to improve the quality of the living area and the appeal of a property over the longer term.

← Older revision		Revision as of 12:19, 5 June 2025
Line 1:		Line 1:
−	[[File:~~EPC RdSAP 9~~.~~94 to 10 BRE spec 1000~~.jpg]]	+	[[File:EPC_RdSAP_9.94_to_10_BRE_spec_1000.jpg\|link=File:EPC_RdSAP_9.94_to_10_BRE_spec_1000.jpg]]

	= Background =		= Background =

−	Energy Performance Certificates (EPCs) are a mechanism to rate energy efficiency of both new and existing buildings and suggest improvements that could be made. Originally introduced to the UK in 2003 via an EU directive, EPCs aimed to standardise efficiency ratings, inspired by successful appliance energy labels that drove market innovation and led to stricter efficiency grading systems over time.	+	Energy Performance Certificates (EPCs) are a mechanism to rate the energy efficiency of both new and existing buildings and suggest improvements that could be made. Originally introduced to the UK in 2003 via an EU directive, EPCs aimed to standardise efficiency ratings, inspired by successful appliance energy labels that drove market innovation and led to stricter efficiency grading systems over time.

−	EPCs, set out the energy efficiency rating of a building from A (most efficient) to G (least efficient) and are valid for 10 years. The EPC contains information about a property’s energy use, typical energy costs and recommendations about how to reduce energy use and save money. The calculation methodology behind residential EPCs is known as the Standard Assessment Procedure (SAP), with a slight variation known as the Reduced Standard Assessment Procedure (RdSAP) which used for existing residential buildings.	+	EPCs set out the energy efficiency rating of a building from A (most efficient) to G (least efficient) and are valid for 10 years. The EPC contains information about a property’s energy use, typical energy costs and recommendations about how to reduce energy use and save money. The calculation methodology behind residential EPCs is known as the Standard Assessment Procedure (SAP), with a slight variation known as the Reduced Standard Assessment Procedure (RdSAP), which is used for existing residential buildings.

−	For buildings other than dwellings the National Calculation Method (NCM) is used which is based on the Simplified Building Energy Model (SBEM), the equivalent of SAP but with a number of differences. Both SAP and SBEM are energy estimating tools rather than actual energy measurement tools. In the case of some public buildings there is also a requirement to use and display a measured energy rating tool based on a yearly assessment, this is ~~call~~ the Display Energy Certificate (DEC). Note that the graphics of a DEC look very similar to that of an EPC once complete, but the methodology behind them is very different, as DEC is a measured rating, ~~where as~~ EPC is estimated.	+	For buildings other than dwellings, the National Calculation Method (NCM) is used, which is based on the Simplified Building Energy Model (SBEM), the equivalent of SAP but with a number of differences. Both SAP and SBEM are energy estimating tools rather than actual energy measurement tools. In the case of some public buildings there is also a requirement to use and display a measured energy rating tool based on a yearly assessment; this is called the Display Energy Certificate (DEC). Note that the graphics of a DEC look very similar to that of an EPC once complete, but the methodology behind them is very different, as DEC is a measured rating, whereas EPC is estimated.

−	Because the methodology behind an EPC is a simplified estimate it has for some time, faced criticism regarding common inaccuracies, which have become more vocal as requirements have become more stringent . Studies have in the past highlighted flaws such as mismeasured floor areas, poor fabric assumptions, occupant usage and so ~~fourth~~ often leading to overestimations of energy use. Inaccuracies in the procedure itself can stem from these assumptions, outdated or simplified modelling software, incorrect data points, human error, behaviour-based variability, weather conditions, building changes over time, default U-values and so on.	+	Because the methodology behind an EPC is a simplified estimate it has for some time faced criticism regarding common inaccuracies, which have become more vocal as requirements have become more stringent. Studies have in the past highlighted flaws such as mismeasured floor areas, poor fabric assumptions, occupant usage and so forth, often leading to overestimations of energy use. Inaccuracies in the procedure itself can stem from these assumptions, outdated or simplified modelling software, incorrect data points, human error, behaviour-based variability, weather conditions, building changes over time, default U-values and so on.

−	The requirements to hold an EPC have gradually changed over time~~, initially~~, from 2008 EPCs became mandatory for all buildings, being sold, built, or rented, then from 2018 with the introduction of the minimum energy efficiency standard (MEES) a minimum EPC rating of 'E' was required for new tenancies. In 2020 this was then expanded to all existing tenancies, in effect meaning that from April 2023, landlord properties with ratings below 'E' could not legally be let. Whilst the new requirements covered much of the rental stock a variety of exemptions were given for short term lets, historical buildings and so ~~fourth~~. In February 2024 the Building Research Establishment (BRE) published an specification for its RdSAP, whilst the ~~Government~~ published a number of consultations regarding MEES and EPCs reviewing both the methodologies and the requirements for these.	+	The requirements to hold an EPC have gradually changed over time. Initially, from 2008, EPCs became mandatory for all buildings being sold, built, or rented, and then from 2018, with the introduction of the minimum energy efficiency standard (MEES), a minimum EPC rating of 'E' was required for new tenancies. In 2020 this was then expanded to all existing tenancies, in effect meaning that from April 2023, landlord properties with ratings below 'E' could not legally be let. Whilst the new requirements covered much of the rental stock, a variety of exemptions were given for short-term lets, historical buildings, and so forth. In February 2024 the Building Research Establishment (BRE) published a specification for its RdSAP, whilst the government published a number of consultations regarding MEES and EPCs, reviewing both the methodologies and the requirements for these.

−	The current government proposal is to raise the minimum EPC rating to 'C' for new tenancies by 2025 and then for all tenancies by 2028, and alongside this ~~changing~~ the process by which exemptions apply. ~~Where as~~ currently certain properties default to having an exemption, the new regime will have the default of applying to all properties, including short term lets, historical buildings and so ~~fourth~~. Whilst certain exemptions will continue to exist, they will need to be applied for, evidenced and recorded on a register, with aspects such as the amount of money ~~spend~~ on energy efficiency improvements being considered.	+	The current government proposal is to raise the minimum EPC rating to 'C' for new tenancies by 2025 and then for all tenancies by 2028, and alongside this, change the process by which exemptions apply. Whereas currently certain properties default to having an exemption, the new regime will have the default of applying to all properties, including short-term lets, historical buildings and so forth. Whilst certain exemptions will continue to exist, they will need to be applied for, evidenced and recorded on a register, with aspects such as the amount of money spent on energy efficiency improvements being considered.

	= Updated methodology =		= Updated methodology =

−	The methodology to calculate the EPC rating level of new buildings has been updated at various points in time with the latest version of SAP, SAP 10.2 including many more data points than were originally considered. The methodology used to calculate the EPC of existing buildings RdSAP, although updated regularly has largely ~~remain~~ the same [https://files.bregroup.com/sap/Rdhttps://files.bregroup.com/sap/RdSAP_2012_9.94-20-09-2019.pdf?_its=JTdCJTIydmlkJTIyJTNBJTIyMzU1NzQxNWQtNjllZi00NDIwLWIxNjktZjE3OTZiOTExMDM0JTIyJTJDJTIyc3RhdGUlMjIlM0ElMjJybHR%2BMTY5Nzc5OTUzOH5sYW5kfjJfNzc4NzZfdnJlZl8wMmUzMzYxZjExOTgyNDM4MmIwNmIzY2FkN2M0ZWNiZSUyMiUyQyUyMnNpdGVJZCUyMiUzQTk4MDAlN0Q%3DSAP_2012_9.94-20-09-2019.pdf?_its=JTdCJTIydmlkJTIyJTNBJTIyMzU1NzQxNWQtNjllZi00NDIwLWIxNjktZjE3OTZiOTExMDM0JTIyJTJDJTIyc3RhdGUlMjIlM0ElMjJybHR%2BMTY5Nzc5OTUzOH5sYW5kfjJfNzc4NzZfdnJlZl8wMmUzMzYxZjExOTgyNDM4MmIwNmIzY2FkN2M0ZWNiZSUyMiUyQyUyMnNpdGVJZCUyMiUzQTk4MDAlN0Q%3D RdSAP v9.94]. However in February 2024 BRE published the specification for the new updated RdSAP10, promising to be a much more detailed calculation of energy performance helping to produce significantly more accurate EPCs for existing buildings. The specification brings the SAP approach for existing dwellings much closer to the approach that is used for new ~~builings~~, as the most significant update to the RdSAP in some 10 years it hopes to resolve many of the criticisms previously held.	+	The methodology to calculate the EPC rating level of new buildings has been updated at various points in time, with the latest version of SAP, SAP 10.2, including many more data points than were originally considered. The methodology used to calculate the EPC of existing buildings, RdSAP, although updated regularly, has largely remained the same, [https://files.bregroup.com/sap/Rdhttps://files.bregroup.com/sap/RdSAP_2012_9.94-20-09-2019.pdf?_its=JTdCJTIydmlkJTIyJTNBJTIyMzU1NzQxNWQtNjllZi00NDIwLWIxNjktZjE3OTZiOTExMDM0JTIyJTJDJTIyc3RhdGUlMjIlM0ElMjJybHR%2BMTY5Nzc5OTUzOH5sYW5kfjJfNzc4NzZfdnJlZl8wMmUzMzYxZjExOTgyNDM4MmIwNmIzY2FkN2M0ZWNiZSUyMiUyQyUyMnNpdGVJZCUyMiUzQTk4MDAlN0Q%3DSAP_2012_9.94-20-09-2019.pdf?_its=JTdCJTIydmlkJTIyJTNBJTIyMzU1NzQxNWQtNjllZi00NDIwLWIxNjktZjE3OTZiOTExMDM0JTIyJTJDJTIyc3RhdGUlMjIlM0ElMjJybHR%2BMTY5Nzc5OTUzOH5sYW5kfjJfNzc4NzZfdnJlZl8wMmUzMzYxZjExOTgyNDM4MmIwNmIzY2FkN2M0ZWNiZSUyMiUyQyUyMnNpdGVJZCUyMiUzQTk4MDAlN0Q%3D RdSAP] [https://files.bregroup.com/sap/Rdhttps://files.bregroup.com/sap/RdSAP_2012_9.94-20-09-2019.pdf?_its=JTdCJTIydmlkJTIyJTNBJTIyMzU1NzQxNWQtNjllZi00NDIwLWIxNjktZjE3OTZiOTExMDM0JTIyJTJDJTIyc3RhdGUlMjIlM0ElMjJybHR%2BMTY5Nzc5OTUzOH5sYW5kfjJfNzc4NzZfdnJlZl8wMmUzMzYxZjExOTgyNDM4MmIwNmIzY2FkN2M0ZWNiZSUyMiUyQyUyMnNpdGVJZCUyMiUzQTk4MDAlN0Q%3DSAP_2012_9.94-20-09-2019.pdf?_its=JTdCJTIydmlkJTIyJTNBJTIyMzU1NzQxNWQtNjllZi00NDIwLWIxNjktZjE3OTZiOTExMDM0JTIyJTJDJTIyc3RhdGUlMjIlM0ElMjJybHR%2BMTY5Nzc5OTUzOH5sYW5kfjJfNzc4NzZfdnJlZl8wMmUzMzYxZjExOTgyNDM4MmIwNmIzY2FkN2M0ZWNiZSUyMiUyQyUyMnNpdGVJZCUyMiUzQTk4MDAlN0Q%3D v9.94]. However, in February 2024, BRE published the specification for the new updated RdSAP10, promising to be a much more detailed calculation of energy performance, helping to produce significantly more accurate EPCs for existing buildings. The specification brings the SAP approach for existing dwellings much closer to the approach that is used for new buildings, as the most significant update to the RdSAP in some 10 years; it hopes to resolve many of the criticisms previously held.

−	The new RdSAP specification has been developed by BRE on behalf of the government for use in existing dwellings based on a site assessment of the property, when the complete data set for SAP ~~calculationn~~ is not available. The RdSAP calculation starting from reduced data is done in two stages. First the collected data (reduced data set) is expanded into a full data set, and then the SAP calculation is undertaken using the expanded data set. The SAP calculation is therefore identical, whether starting from a reduced data set or a full data set. This version of RdSAP forms part of SAP 10.2 specification and provides a data input set for use with version 10.2 of SAP.	+	The new RdSAP specification has been developed by BRE on behalf of the government for use in existing dwellings based on a site assessment of the property when the complete data set for SAP calculation is not available. The RdSAP calculation starting from reduced data is done in two stages. First the collected data (reduced data set) is expanded into a full data set, and then the SAP calculation is undertaken using the expanded data set. The SAP calculation is therefore identical, whether starting from a reduced data set or a full data set. This version of RdSAP forms part of the SAP 10.2 specification and provides a data input set for use with version 10.2 of SAP.

−	BRE state that there are significant changes in RdSAP 10 when compared to ~~RdSAP2012~~ specification and these include:	+	BRE state that there are significant changes in RdSAP 10 when compared to the RdSAP 2012 specification, and these include:

	* Window measurements required for all windows		* Window measurements required for all windows
	* Location of each window allocated to main walls or each extension, or alternative walls		* Location of each window allocated to main walls or each extension, or alternative walls
	* Thermal properties of insulation revised		* Thermal properties of insulation revised
−	* Roof insulation details have more options	+	* Roof insulation details have more options.
	* Floor insulation revised; heated basement details added		* Floor insulation revised; heated basement details added
	* Table of Window U-Values expanded		* Table of Window U-Values expanded
−	* U-values of brick ~~wall~~ revised to account wall thickness	+	* U-values of brick walls revised to account for wall thickness
	* U-values of stone walls revised		* U-values of stone walls revised
−	* Curtain wall added as new wall type	+	* Curtain wall added as a new wall type
	* Window shutters added as a new feature		* Window shutters added as a new feature
	* Hot water tank size included		* Hot water tank size included
	* Hot water tank insulation included		* Hot water tank insulation included
−	* Room in roof (RR) revised to take into ~~the~~ account all elements ~~inclu9ding~~ continuous main wall	+	* Room in roof (RR) revised to take into account all elements, including the continuous main wall.
	* Additional alternative/shelter wall added		* Additional alternative/shelter wall added
−	* Mechanical ventilation is treated as in full SAP allowing PCDB entry, still allowing default values	+	* Mechanical ventilation is treated as in full SAP, allowing PCDB entry and still allowing default values.
	* PV calculated as in SAP10.2		* PV calculated as in SAP10.2
	* PV Diverter for water heating added		* PV Diverter for water heating added
−	* PV ~~Batteries~~ added	+	* PV batteries added
	* Ventilation algorithm allows more options		* Ventilation algorithm allows more options
−	* Air pressure test ~~result~~ can be used if available	+	* Air pressure test results can be used if available.
	* New age-band M added, and all tables of U-values updated		* New age-band M added, and all tables of U-values updated
−	* Data for Isle of Man added for completeness of information	+	* Data for the Isle of Man added for completeness of information
−	* Table 32 with the RdSAP10-specific fuel prices replaces fuel prices in Table 12 of SAP10.2	+	* Table 32 with the RdSAP10-specific fuel prices replaces fuel prices in Table 12 of SAP10.2.
	* RdSAP10-specific metrics added to replace SAP metrics in SAP10.2		* RdSAP10-specific metrics added to replace SAP metrics in SAP10.2
−	* Small scale hydro added as in SAP10.2	+	* Small-scale hydro added as in SAP10.2
−	* Flue gas heat recovery -calculation according to SAP 10.2.	+	* Flue gas heat recovery – calculation according to SAP 10.2.
−	* ~~Waste water~~ heat recovery - calculation according to SAP 10.2.	+	* Wastewater heat recovery – calculation according to SAP 10.2.
−	* Heat pumps - Calculation according to SAP 10.2.	+	* Heat pumps – Calculation according to SAP 10.2.
	* Changes to Table 21 of improvement measures (former RdSAP Appendix T) include:		* Changes to Table 21 of improvement measures (former RdSAP Appendix T) include:
	** Improved U-values revised for all building elements		** Improved U-values revised for all building elements
	** Measure to insulate party wall removed		** Measure to insulate party wall removed
	** Order of measures for Northern Ireland removed		** Order of measures for Northern Ireland removed
−	** Air and ground source heat pumps not alternative measures ~~anymore~~	+	** Air and ground source heat pumps are not alternative measures any more.
	** PV battery and PV diverters added		** PV battery and PV diverters added