How to deal with retrofit risks - Revision history

Designing Buildings at 07:59, 11 December 2020

2020-12-11T07:59:34Z

← Older revision		Revision as of 07:59, 11 December 2020
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	* Understanding the performance of solid walls.		* Understanding the performance of solid walls.

−	[[Category:Conservation]] [[Category:~~History~~]] [[Category:~~Research_/_Innovation~~]] [[Category:~~DCN_Research,_Development_and_Innovation~~]] [[Category:Theory]] [[Category:Construction_techniques]]	+	[[Category:Conservation]] [[Category:DCN_Guidance]] [[Category:DCN_Research,_Development_and_Innovation]] [[Category:History]] [[Category:Research_/_Innovation]] [[Category:Theory]] [[Category:Construction_techniques]]

Designing Buildings at 09:16, 20 May 2020

2020-05-20T09:16:23Z

← Older revision		Revision as of 09:16, 20 May 2020
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	* Retrofit, refurbishment and the growth of connected HVAC technology.		* Retrofit, refurbishment and the growth of connected HVAC technology.
	* Retrofit.		* Retrofit.
		+	* Retrofit and traditional approaches to comfort.
	* Retrofitting traditional buildings.		* Retrofitting traditional buildings.
	* The Each Home Counts report and traditional buildings.		* The Each Home Counts report and traditional buildings.
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	* Understanding the performance of solid walls.		* Understanding the performance of solid walls.

−	[[Category:Conservation]] [[Category:History]] [[Category:Research_/_Innovation]] [[Category:Theory]] [[Category:Construction_techniques]]	+	[[Category:Conservation]] [[Category:History]] [[Category:Research_/_Innovation]] [[Category:DCN_Research,_Development_and_Innovation]] [[Category:Theory]] [[Category:Construction_techniques]]

Designing Buildings at 08:02, 29 February 2020

2020-02-29T08:02:41Z

← Older revision		Revision as of 08:02, 29 February 2020
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	* National Refurbishment Centre.		* National Refurbishment Centre.
	* New energy retrofit concept: 'renovation trains' for mass housing.		* New energy retrofit concept: 'renovation trains' for mass housing.
		+	* PAS 2035.
	* Renovation v refurbishment v retrofit.		* Renovation v refurbishment v retrofit.
	* Retrofit coordinator.		* Retrofit coordinator.

Designing Buildings at 11:49, 23 December 2019

2019-12-23T11:49:32Z

← Older revision		Revision as of 11:49, 23 December 2019
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	--[[User:Institute_of_Historic_Building_Conservation\|Institute of Historic Building Conservation]]		--[[User:Institute_of_Historic_Building_Conservation\|Institute of Historic Building Conservation]]

−	~~= Find out more =~~	+	= Related articles on Designing Buildings Wiki =
−		+
−	=== Related articles on Designing Buildings Wiki ===	+

	* Bonfield Review.		* Bonfield Review.
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	* Energy efficiency for the National Trust.		* Energy efficiency for the National Trust.
	* Energy efficiency of traditional buildings.		* Energy efficiency of traditional buildings.
		+	* Energy efficiency retrofit training videos.
	* Energy-related retrofits of buildings and urban areas, a comparison between Germany and the UK.		* Energy-related retrofits of buildings and urban areas, a comparison between Germany and the UK.
	* Home Energy Masterplan.		* Home Energy Masterplan.

Designing Buildings at 11:01, 28 January 2018

2018-01-28T11:01:40Z

← Older revision		Revision as of 11:01, 28 January 2018
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	* Bonfield Review.		* Bonfield Review.
	* Ecobuild 2016 - Making the business case for large scale retrofit investment.		* Ecobuild 2016 - Making the business case for large scale retrofit investment.
		+	* Energy Efficiency and Comfort of Historic Buildings.
	* Energy efficiency for the National Trust.		* Energy efficiency for the National Trust.
	* Energy efficiency of traditional buildings.		* Energy efficiency of traditional buildings.

Editor at 14:49, 28 September 2017

2017-09-28T14:49:33Z

← Older revision		Revision as of 14:49, 28 September 2017
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	The problems caused by moisture in building structures are well known. There is a large body of literature addressing issues including rising and penetrating dampness and interstitial condensation. For regulatory purposes the key document is the BS Code of Practice for condensation in buildings, BS5250:2011, which is referenced in the three sets of regulations in the UK. Apart from a discussion on the principles of condensation risk, the main content of BS5250 is prescriptive guidance on how elements such as walls and roofs should be designed and constructed. Many, if not most, designers will refer to this guidance and not carry out any more complex assessments.		The problems caused by moisture in building structures are well known. There is a large body of literature addressing issues including rising and penetrating dampness and interstitial condensation. For regulatory purposes the key document is the BS Code of Practice for condensation in buildings, BS5250:2011, which is referenced in the three sets of regulations in the UK. Apart from a discussion on the principles of condensation risk, the main content of BS5250 is prescriptive guidance on how elements such as walls and roofs should be designed and constructed. Many, if not most, designers will refer to this guidance and not carry out any more complex assessments.

−	If a more detailed analysis is necessary, BS5250 refers to a calculation procedure specified in ISO 13788, which uses a ‘Glaser’ procedure, taking account only of steady-state vapour diffusion. While this may be adequate for some structures such as flat roofs (and even here there are situations where it is inadequate), it does not represent the whole picture for constructions such as masonry walls where very large amounts of water are stored in the fabric. No account is taken of rain impacts and solar gain on the outside surface, liquid water movement, and the effect of moisture on the thermal and moisture transport properties of materials. A further standard, BS EN 15026:2007 Hygrothermal performance of building components and building elements: assessment of moisture transfer by numerical simulation, was developed to address these issues. This is becoming used in the UK through the German software WUFI (which can run calculations using EN 15026), but there is no robust protocol for using this standard in the UK.	+	If a more detailed analysis is necessary, BS5250 refers to a calculation procedure specified in ISO 13788, which uses a ‘Glaser’ procedure, taking account only of steady-state vapour diffusion. While this may be adequate for some structures such as flat roofs (and even here there are situations where it is inadequate), it does not represent the whole picture for constructions such as masonry walls where very large amounts of water are stored in the fabric. No account is taken of rain impacts and solar gain on the outside surface, liquid water movement, and the effect of moisture on the thermal and moisture transport properties of materials.
		+
		+	A further standard, BS EN 15026:2007 Hygrothermal performance of building components and building elements: assessment of moisture transfer by numerical simulation, was developed to address these issues. This is becoming used in the UK through the German software WUFI (which can run calculations using EN 15026), but there is no robust protocol for using this standard in the UK.

	There are a number of difficulties with this approach at present:		There are a number of difficulties with this approach at present:
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	* The creation of more robust details, reducing the over-reliance on sealants and workmanship.		* The creation of more robust details, reducing the over-reliance on sealants and workmanship.

−	If the effect of thermal bridging is not taken into consideration when calculating potential heat loss from a building, it is likely that the overall heat loss will be underestimated. It follows that if buildings are improved through insulation but thermal bridges remain, heat loss will be concentrated at the point of the bridge relative to the newly improved walls. While it is desirable to minimise this effect to help reduce heating costs, it can also be the cause of physical problems. Since heat will transfer out of the building more readily at the point of a thermal bridge, the internal surface temperature at that point will generally be reduced relative to the surrounding surface area. When the temperature difference reaches a critical ratio, measured as the temperature factor (fRsi) at the junction, condensation can form, which can lead to problems such as mould growth.	+	If the effect of thermal bridging is not taken into consideration when calculating potential heat loss from a building, it is likely that the overall heat loss will be underestimated. It follows that if buildings are improved through insulation but thermal bridges remain, heat loss will be concentrated at the point of the bridge relative to the newly improved walls. While it is desirable to minimise this effect to help reduce heating costs, it can also be the cause of physical problems.
		+
		+	Since heat will transfer out of the building more readily at the point of a thermal bridge, the internal surface temperature at that point will generally be reduced relative to the surrounding surface area. When the temperature difference reaches a critical ratio, measured as the temperature factor (fRsi) at the junction, condensation can form, which can lead to problems such as mould growth.
		+
		+	Latest research indicates that when reveals and penetrations are not insulated, the temperature factor and subsequent cold bridge are actually worse than before the walls were insulated. This results in a concentration of risk in a two-dimensional junction that is least capable of dealing with a drop in temperature. Modelling indicates that this area contributes significantly to the heat loss from a building after improvements.

−	Latest research indicates that when reveals and penetrations are not insulated, the temperature factor and subsequent cold bridge are actually worse than before the walls were insulated. This results in a concentration of risk in a two-dimensional junction that is least capable of dealing with a drop in temperature. Modelling indicates that this area contributes significantly to the heat loss from a building after improvements. The losses through cold bridging have been identified to be the cause of 19 per cent of heat loss through a building envelope. This lack of attention to detail is understandable in view of the desire to avoid bridging the damp-proof membrane or course, but careful treatment of this area can result in reduced cold bridging and subsequent risks.	+	The losses through cold bridging have been identified to be the cause of 19 per cent of heat loss through a building envelope. This lack of attention to detail is understandable in view of the desire to avoid bridging the damp-proof membrane or course, but careful treatment of this area can result in reduced cold bridging and subsequent risks.

	-----		-----
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	* Energy efficiency of traditional buildings.		* Energy efficiency of traditional buildings.
	* Energy-related retrofits of buildings and urban areas, a comparison between Germany and the UK.		* Energy-related retrofits of buildings and urban areas, a comparison between Germany and the UK.
		+	* Home Energy Masterplan.
	* IHBC articles.		* IHBC articles.
	* National Refurbishment Centre.		* National Refurbishment Centre.

Designing Buildings at 08:32, 24 September 2017

2017-09-24T08:32:24Z

← Older revision		Revision as of 08:32, 24 September 2017
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	* Retrofit, refurbishment and the growth of connected HVAC technology.		* Retrofit, refurbishment and the growth of connected HVAC technology.
	* Retrofit.		* Retrofit.
		+	* Retrofitting traditional buildings.
	* The Each Home Counts report and traditional buildings.		* The Each Home Counts report and traditional buildings.
	* The Institute of Historic Building Conservation.		* The Institute of Historic Building Conservation.

Designing Buildings at 13:51, 8 September 2017

2017-09-08T13:51:43Z

← Older revision		Revision as of 13:51, 8 September 2017
Line 74:		Line 74:
	* The Each Home Counts report and traditional buildings.		* The Each Home Counts report and traditional buildings.
	* The Institute of Historic Building Conservation.		* The Institute of Historic Building Conservation.
		+	* Understanding the performance of solid walls.

	[[Category:Conservation]] [[Category:History]] [[Category:Research_/_Innovation]] [[Category:Theory]] [[Category:Construction_techniques]]		[[Category:Conservation]] [[Category:History]] [[Category:Research_/_Innovation]] [[Category:Theory]] [[Category:Construction_techniques]]

Designing Buildings at 10:24, 15 August 2017

2017-08-15T10:24:07Z

← Older revision		Revision as of 10:24, 15 August 2017
Line 62:		Line 62:
	* Bonfield Review.		* Bonfield Review.
	* Ecobuild 2016 - Making the business case for large scale retrofit investment.		* Ecobuild 2016 - Making the business case for large scale retrofit investment.
		+	* Energy efficiency for the National Trust.
	* Energy efficiency of traditional buildings.		* Energy efficiency of traditional buildings.
	* Energy-related retrofits of buildings and urban areas, a comparison between Germany and the UK.		* Energy-related retrofits of buildings and urban areas, a comparison between Germany and the UK.

Designing Buildings: Protected "How to deal with retrofit risks" ([edit=sysop] (indefinite) [move=sysop] (indefinite))

2017-08-11T09:40:57Z

Protected "How to deal with retrofit risks" ([edit=sysop] (indefinite) [move=sysop] (indefinite))

← Older revision

Revision as of 09:40, 11 August 2017