Passivhaus vs SAP - Revision history

Designing Buildings at 11:42, 15 March 2023

2023-03-15T11:42:40Z

← Older revision		Revision as of 11:42, 15 March 2023
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−	This article originally appeared in the Architectural Technology Journal (at) issue 135 published by CIAT in fall 2020 under the headline, '~~[https://dmiebooks.com/Client/CIAT/135/index.html~~ So which is best – Passivhaus or SAP?]' It was written by Stuart Fairlie, Technical and Operations Director, Elmhurst Energy.	+	This article originally appeared in the Architectural Technology Journal (at) issue 135 published by CIAT in fall 2020 under the headline, 'So which is best – Passivhaus or SAP?' It was written by Stuart Fairlie, Technical and Operations Director, Elmhurst Energy.

	--[[User:CIAT\|CIAT]]		--[[User:CIAT\|CIAT]]

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

	* CIAT articles.		* CIAT articles.

Editor at 10:06, 18 February 2021

2021-02-18T10:06:04Z

← Older revision		Revision as of 10:06, 18 February 2021
Line 75:		Line 75:
	This article originally appeared in the Architectural Technology Journal (at) issue 135 published by CIAT in fall 2020 under the headline, '[https://dmiebooks.com/Client/CIAT/135/index.html So which is best – Passivhaus or SAP?]' It was written by Stuart Fairlie, Technical and Operations Director, Elmhurst Energy.		This article originally appeared in the Architectural Technology Journal (at) issue 135 published by CIAT in fall 2020 under the headline, '[https://dmiebooks.com/Client/CIAT/135/index.html So which is best – Passivhaus or SAP?]' It was written by Stuart Fairlie, Technical and Operations Director, Elmhurst Energy.

−	[[User:CIAT\|CIAT]]	+	--[[User:CIAT\|CIAT]]

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

Editor at 13:41, 17 February 2021

2021-02-17T13:41:42Z

← Older revision		Revision as of 13:41, 17 February 2021
Line 73:		Line 73:

	-----		-----
−	This article originally appeared in the Architectural Technology Journal (at) issue 135 published by CIAT in fall 2020 under the headline, 'So which is best – Passivhaus or SAP?' It was written by Stuart Fairlie, Technical and Operations Director, Elmhurst Energy.	+	This article originally appeared in the Architectural Technology Journal (at) issue 135 published by CIAT in fall 2020 under the headline, '[https://dmiebooks.com/Client/CIAT/135/index.html So which is best – Passivhaus or SAP?]' It was written by Stuart Fairlie, Technical and Operations Director, Elmhurst Energy.

	[[User:CIAT\|CIAT]]		[[User:CIAT\|CIAT]]
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	* CIAT articles.		* CIAT articles.
		+	* Code for sustainable homes.
		+	* Energy performance certificate EPC.
		+	* Minimum energy efficiency standard regulations for domestic and non-domestic buildings.
		+	* National Calculation Method.
		+	* Passivhaus.
		+	* Standard Assessment Procedure SAP.
		+
		+	[[Category:DCN_Guidance]] [[Category:Sustainability]]

Editor at 12:38, 17 February 2021

2021-02-17T12:38:40Z

← Older revision		Revision as of 12:38, 17 February 2021
Line 17:		Line 17:
	That rating is basically a cost index which tells you how expensive a home is to run. So far, so good – the house builders and estate agents can work with that.		That rating is basically a cost index which tells you how expensive a home is to run. So far, so good – the house builders and estate agents can work with that.

−	~~[[File:PHPPorSAPCIAT~~.~~jpg]]~~	+	{\|
		+	\|width="100%"\| Energy Performance Certificates (EPC) go online
		+	\|-
		+	\|
		+	An EPC register was introduced by the UK Government in September 2020 to improve access to all EPCs in England, Wales and Northern Ireland. This register provides online copies of EPCs, accessible via a link given to the client by the energy assessor once the EPC has been lodged. All existing EPCs are also being moved across to the online format.
		+
		+	The Scottish register is unaffected. It continues to be provided by the Energy Savings Trust for the Scottish Government.
		+
		+	An Energy Performance Certificate is required for properties when constructed, sold or let. It is typically valid for 10 years.
		+	\|}

	But there is a fundamental problem with EPCs for some experts, as the EPC for a new home is calculated using the Standard Assessment Procedure (SAP). This is a building physics modelling method which has also been at the heart of the compliance framework for UK Building Regulations since 1995.		But there is a fundamental problem with EPCs for some experts, as the EPC for a new home is calculated using the Standard Assessment Procedure (SAP). This is a building physics modelling method which has also been at the heart of the compliance framework for UK Building Regulations since 1995.
Line 53:		Line 62:
	We already have creative ideas about how we could present key performance data for a property in a clear and visually engaging manner. We also wish to give equal prominence to carbon emissions, energy demand, running costs and fabric efficiency.		We already have creative ideas about how we could present key performance data for a property in a clear and visually engaging manner. We also wish to give equal prominence to carbon emissions, energy demand, running costs and fabric efficiency.

−	{\|	+	[[File:PHPPorSAPCIAT.jpg\|link=File:PHPPorSAPCIAT.jpg]]
−	~~\|width~~=~~"100%"\| Energy Performance Certificates (EPC) go online~~	+
−	\|-	+
−	\|	+
−	~~An EPC register was introduced by the UK Government in September 2020 to improve access to all EPCs in England, Wales and Northern Ireland~~. This register provides online copies of EPCs, accessible via a link given to the client by the energy assessor once the EPC has been lodged. All existing EPCs are also being moved across to the online format.	+
−		+
−	~~The Scottish register is unaffected. It continues to be provided by the Energy Savings Trust for the Scottish Government.~~	+
−		+
−	~~An Energy Performance Certificate is required for properties when constructed, sold or let. It is typically valid for 10 years.~~	+
−		+
−	But as Stuart Fairlie of Elmhurst Energy says, “EPCs should be updated more frequently to reflect the current state of our buildings. Within 10 years so much will have changed – not least the energy costs and savings available, but most likely to the property itself, with incremental improvements such as the installation of a new boiler or replacement windows. To reflect current fuel prices, an EPC should really never be older than three years to ensure that estimates and recommendations are relevant.”	+
−	\|}	+

	We think we can provide clarity regarding the scope of the of the energy use covered, such as space heating only, regulated energy or all energy use. We can standardise the units of measurement of a home’s performance to allow for direct and fair comparison. We can develop a common energy reporting process capable of being driven by either PHPP or SAP as the starting point.		We think we can provide clarity regarding the scope of the of the energy use covered, such as space heating only, regulated energy or all energy use. We can standardise the units of measurement of a home’s performance to allow for direct and fair comparison. We can develop a common energy reporting process capable of being driven by either PHPP or SAP as the starting point.

Editor at 12:35, 17 February 2021

2021-02-17T12:35:47Z

← Older revision		Revision as of 12:35, 17 February 2021
Line 1:		Line 1:
−	[[File:PHPP.jpg]]	+	[[File:PHPP.jpg\|link=File:PHPP.jpg]]

	= Introduction =		= Introduction =
Line 7:		Line 7:
	= Interpreting energy efficiency =		= Interpreting energy efficiency =

−	Energy efficiency is one of those issues which usually means something different to each expert you ask. Some talk about it in terms of carbon. Others talk about space heating demand and others focus on fuel poverty and the need to reduce overall energy costs. Consider the design, construction and marketing of green new homes, and you get the same thing. Some are promoted as ultra-low energy, some are ‘zero carbon’ or even ‘carbon positive’, and some are celebrated for very low fuel bills.	+	Energy efficiency is one of those issues which usually means something different to each expert you ask. Some talk about it in terms of carbon. Others talk about space heating demand and others focus on fuel poverty and the need to reduce overall energy costs.

−	~~The law requires~~ the ~~production~~ of ~~an Energy Performance Certificate (EPC) for all~~ new ~~build~~ homes and ~~for existing dwellings at~~ the ~~point of sale or rent~~. ~~Most people just think of an EPC~~ as ~~the colourful A to G~~ energy ~~efficiency rating~~.	+	Consider the design, construction and marketing of green new homes, and you get the same thing. Some are promoted as ultra-low energy, some are ‘zero carbon’ or even ‘carbon positive’ and some are celebrated for very low fuel bills.

−	That rating is basically a cost index which tells you how expensive a home is to run. So far, so good – the ~~housebuilders~~ and estate agents can work with that.	+	= EPCs =
		+
		+	The law requires the production of an Energy Performance Certificate (EPC) for all newly build homes and for existing dwellings at the point of sale or rent. Most people just think of an EPC as the colourful A to G energy efficiency rating.
		+
		+	That rating is basically a cost index which tells you how expensive a home is to run. So far, so good – the house builders and estate agents can work with that.
		+
		+	[[File:PHPPorSAPCIAT.jpg]]

	But there is a fundamental problem with EPCs for some experts, as the EPC for a new home is calculated using the Standard Assessment Procedure (SAP). This is a building physics modelling method which has also been at the heart of the compliance framework for UK Building Regulations since 1995.		But there is a fundamental problem with EPCs for some experts, as the EPC for a new home is calculated using the Standard Assessment Procedure (SAP). This is a building physics modelling method which has also been at the heart of the compliance framework for UK Building Regulations since 1995.
		+
		+	= SAP =

	SAP is regularly and vocally criticised for being inaccurate. It assumes every dwelling is at the centre of the country, somewhere in the east Pennines, so that the climate conditions are always the same. It uses other assumptions to figure out a ‘typical’ number of occupants and their ‘typical’ heating patterns.		SAP is regularly and vocally criticised for being inaccurate. It assumes every dwelling is at the centre of the country, somewhere in the east Pennines, so that the climate conditions are always the same. It uses other assumptions to figure out a ‘typical’ number of occupants and their ‘typical’ heating patterns.

−	While there are also an environmental impact rating and an indication of space heating demand expressed in kilowatt hours per year (kWh/year) generated by a SAP ~~calculation~~ and hidden right at the back of the EPC report, these are not considered accurate~~, they~~ do not cover all fuel uses, the carbon data needs updating~~, and~~ homebuyers do not tend to pay any attention to those ratings anyway.	+	While there are also an environmental impact rating and an indication of space heating demand expressed in kilowatt hours per year (kWh/year) generated by SAP calculations and hidden right at the back of the EPC report, these are not considered accurate. They do not cover all fuel uses and the carbon data needs updating; homebuyers do not tend to pay any attention to those ratings anyway.

	SAP is a blunt tool, admittedly, but one that allows us to compare across different dwellings in different locations. So, it has its uses!		SAP is a blunt tool, admittedly, but one that allows us to compare across different dwellings in different locations. So, it has its uses!

−	In another camp is the Passivhaus community which makes use of the Passivhaus Planning Package (PHPP). PHPP is another building physics methodology which focuses on calculating a kWh/Year rating for a new dwelling and uses very specific local climate data and other inputs to understand how a home will actually perform in use. Organisations seeking to drive improvements in energy efficiency should use this measurement, space heating demand, as the primary metric, say the Passivhaus experts.	+	= PHPP =
		+
		+	In another camp is the Passivhaus community which makes use of the Passivhaus Planning Package (PHPP). PHPP is another building physics methodology which focuses on calculating a kWh/Year rating for a new dwelling and uses very specific local climate data and other inputs to understand how a home will actually perform in use.
		+
		+	Organisations seeking to drive improvements in energy efficiency should use this measurement, space heating demand, as the primary metric, say the Passivhaus experts.

	= So who is right? =		= So who is right? =
Line 33:		Line 45:
	Perhaps we should not have been that surprised. Physics is physics, after all.		Perhaps we should not have been that surprised. Physics is physics, after all.

−	But this work now allows us to move forward on a solution to help housebuilders, designers, energy consultants and other green building professionals. This should finally allow for a direct and fair comparison between all homes, whatever their type or level of energy performance.	+	= Pooling resources =

−	~~Our objective is~~ to ~~learn from the strengths~~ and ~~weaknesses of both approaches, thus improving both~~. ~~We want to make it easier to demonstrate compliance~~ for ~~both Building Regulation purposes~~ and ~~for those that want to build~~ homes ~~that are above and beyond the minimum regulatory standards~~.	+	This work allows us to move forward on a solution to help house builders, designers, energy consultants and other green building professionals. This should finally allow for a direct and fair comparison between all homes, whatever their type or level of energy performance.

−	We already have creative ideas about how we could present key performance data for a property in a clear and visually engaging manner~~, and giving~~ equal prominence to carbon emissions, energy demand, running costs and fabric efficiency.	+	Our objective is to learn from the strengths and weaknesses of both approaches, thus improving both. We want to make it easier to demonstrate compliance for both Building Regulation purposes and for those who want to build homes that are above and beyond the minimum regulatory standards.
		+
		+	We already have creative ideas about how we could present key performance data for a property in a clear and visually engaging manner. We also wish to give equal prominence to carbon emissions, energy demand, running costs and fabric efficiency.

	{\|		{\|
Line 43:		Line 57:
	\|-		\|-
	\|		\|
−	An EPC ~~Register~~ was introduced by the UK Government in September 2020 to improve access to all EPCs in England, Wales and Northern Ireland. ~~The new~~ register provides online copies of EPCs, accessible via a link given to the client by the energy assessor once the EPC has been lodged. All existing EPCs are also being moved across to the online format. The Scottish register is unaffected ~~and~~ continues to be provided by the Energy Savings Trust for the Scottish Government.	+	An EPC register was introduced by the UK Government in September 2020 to improve access to all EPCs in England, Wales and Northern Ireland. This register provides online copies of EPCs, accessible via a link given to the client by the energy assessor once the EPC has been lodged. All existing EPCs are also being moved across to the online format.
		+
		+	The Scottish register is unaffected. It continues to be provided by the Energy Savings Trust for the Scottish Government.
		+
		+	An Energy Performance Certificate is required for properties when constructed, sold or let. It is typically valid for 10 years.

−	~~An Energy Performance Certificate is required for properties when constructed, sold or let. It is typically valid for ten years.~~ But as Stuart Fairlie of Elmhurst Energy says: “EPCs should be updated more frequently to reflect the current state of our buildings. Within ~~ten~~ years so much will have changed – not least the energy costs and savings available, but most likely to property itself, with incremental improvements such as the installation of a new boiler or replacement windows. To reflect current fuel prices, an EPC should really never be older than three years to ensure that estimates and recommendations are relevant.”	+	But as Stuart Fairlie of Elmhurst Energy says, “EPCs should be updated more frequently to reflect the current state of our buildings. Within 10 years so much will have changed – not least the energy costs and savings available, but most likely to the property itself, with incremental improvements such as the installation of a new boiler or replacement windows. To reflect current fuel prices, an EPC should really never be older than three years to ensure that estimates and recommendations are relevant.”
	\|}		\|}

	We think we can provide clarity regarding the scope of the of the energy use covered, such as space heating only, regulated energy or all energy use. We can standardise the units of measurement of a home’s performance to allow for direct and fair comparison. We can develop a common energy reporting process capable of being driven by either PHPP or SAP as the starting point.		We think we can provide clarity regarding the scope of the of the energy use covered, such as space heating only, regulated energy or all energy use. We can standardise the units of measurement of a home’s performance to allow for direct and fair comparison. We can develop a common energy reporting process capable of being driven by either PHPP or SAP as the starting point.

−	Both SAP and PHPP are effective tools at what they do. It is horses for courses. But bringing them together in some way and aligning with national regulations will make life easier for energy assessors and ~~housebuilders~~ while also presenting consumers with a clear and unambiguous statement of a home’s overall performance.	+	Both SAP and PHPP are effective tools at what they do. It is horses for courses. But bringing them together in some way and aligning with national regulations will make life easier for energy assessors and house builders while also presenting consumers with a clear and unambiguous statement of a home’s overall performance.

	Given a common set of easy-to-understand results, we will all be able to make a fair comparison between homes, and therefore make a choice based on what matters most to us.		Given a common set of easy-to-understand results, we will all be able to make a fair comparison between homes, and therefore make a choice based on what matters most to us.

Editor: Created page with "File:PHPP.jpg = Introduction = A long-running debate between different groups of green house building experts seems to be reaching a creative conclusion. = Interpreting en..."

2021-02-17T12:18:18Z

Created page with "File:PHPP.jpg = Introduction = A long-running debate between different groups of green house building experts seems to be reaching a creative conclusion. = Interpreting en..."

New page

[[File:PHPP.jpg]]

= Introduction =

A long-running debate between different groups of green house building experts seems to be reaching a creative conclusion.

= Interpreting energy efficiency =

Energy efficiency is one of those issues which usually means something different to each expert you ask. Some talk about it in terms of carbon. Others talk about space heating demand and others focus on fuel poverty and the need to reduce overall energy costs. Consider the design, construction and marketing of green new homes, and you get the same thing. Some are promoted as ultra-low energy, some are ‘zero carbon’ or even ‘carbon positive’, and some are celebrated for very low fuel bills.

The law requires the production of an Energy Performance Certificate (EPC) for all new build homes and for existing dwellings at the point of sale or rent. Most people just think of an EPC as the colourful A to G energy efficiency rating.

That rating is basically a cost index which tells you how expensive a home is to run. So far, so good – the housebuilders and estate agents can work with that.

But there is a fundamental problem with EPCs for some experts, as the EPC for a new home is calculated using the Standard Assessment Procedure (SAP). This is a building physics modelling method which has also been at the heart of the compliance framework for UK Building Regulations since 1995.

SAP is regularly and vocally criticised for being inaccurate. It assumes every dwelling is at the centre of the country, somewhere in the east Pennines, so that the climate conditions are always the same. It uses other assumptions to figure out a ‘typical’ number of occupants and their ‘typical’ heating patterns.

While there are also an environmental impact rating and an indication of space heating demand expressed in kilowatt hours per year (kWh/year) generated by a SAP calculation and hidden right at the back of the EPC report, these are not considered accurate, they do not cover all fuel uses, the carbon data needs updating, and homebuyers do not tend to pay any attention to those ratings anyway.

SAP is a blunt tool, admittedly, but one that allows us to compare across different dwellings in different locations. So, it has its uses!

In another camp is the Passivhaus community which makes use of the Passivhaus Planning Package (PHPP). PHPP is another building physics methodology which focuses on calculating a kWh/Year rating for a new dwelling and uses very specific local climate data and other inputs to understand how a home will actually perform in use. Organisations seeking to drive improvements in energy efficiency should use this measurement, space heating demand, as the primary metric, say the Passivhaus experts.

= So who is right? =

Well, all I know is that every year of squabbling between green building experts just leads to more delay in achieving our goals. So three leading organisations in this space – the AECB, Passivhaus Trust and Elmhurst Energy – got together to carry out a detailed piece of technical research comparing PHPP and SAP calculations and outputs to see if they could put the arguments to bed.

It turns out that the two sides are not as far apart as we once thought.

We have concluded, contrary to some rhetoric, that the core of the models is very similar. While PHPP allows a user to enter more data in some areas and considers some elements such as thermal junctions differently from SAP, the physics behind the methodologies that calculate the energy efficiency of the building fabric is very similar.

Perhaps we should not have been that surprised. Physics is physics, after all.

But this work now allows us to move forward on a solution to help housebuilders, designers, energy consultants and other green building professionals. This should finally allow for a direct and fair comparison between all homes, whatever their type or level of energy performance.

Our objective is to learn from the strengths and weaknesses of both approaches, thus improving both. We want to make it easier to demonstrate compliance for both Building Regulation purposes and for those that want to build homes that are above and beyond the minimum regulatory standards.

We already have creative ideas about how we could present key performance data for a property in a clear and visually engaging manner, and giving equal prominence to carbon emissions, energy demand, running costs and fabric efficiency.

{|
|width="100%"| Energy Performance Certificates (EPC) go online
|-
|
An EPC Register was introduced by the UK Government in September 2020 to improve access to all EPCs in England, Wales and Northern Ireland. The new register provides online copies of EPCs, accessible via a link given to the client by the energy assessor once the EPC has been lodged. All existing EPCs are also being moved across to the online format. The Scottish register is unaffected and continues to be provided by the Energy Savings Trust for the Scottish Government.

An Energy Performance Certificate is required for properties when constructed, sold or let. It is typically valid for ten years. But as Stuart Fairlie of Elmhurst Energy says: “EPCs should be updated more frequently to reflect the current state of our buildings. Within ten years so much will have changed – not least the energy costs and savings available, but most likely to property itself, with incremental improvements such as the installation of a new boiler or replacement windows. To reflect current fuel prices, an EPC should really never be older than three years to ensure that estimates and recommendations are relevant.”
|}

We think we can provide clarity regarding the scope of the of the energy use covered, such as space heating only, regulated energy or all energy use. We can standardise the units of measurement of a home’s performance to allow for direct and fair comparison. We can develop a common energy reporting process capable of being driven by either PHPP or SAP as the starting point.

Both SAP and PHPP are effective tools at what they do. It is horses for courses. But bringing them together in some way and aligning with national regulations will make life easier for energy assessors and housebuilders while also presenting consumers with a clear and unambiguous statement of a home’s overall performance.

Given a common set of easy-to-understand results, we will all be able to make a fair comparison between homes, and therefore make a choice based on what matters most to us.

At its heart, this is a story of two different approaches, but one common goal. All of us working on this initiative agree that our aims are the same – our commitment is to facilitate the building of more energy efficient homes. What are currently considered to be high performing homes will, very soon, become the norm. By working together that goal will be easier to achieve.

-----
This article originally appeared in the Architectural Technology Journal (at) issue 135 published by CIAT in fall 2020 under the headline, 'So which is best – Passivhaus or SAP?' It was written by Stuart Fairlie, Technical and Operations Director, Elmhurst Energy.

[[User:CIAT|CIAT]]

= Related articles on Designing Buildings Wiki =

* CIAT articles.