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HBF 2012 consultation on changes to Part L (Conservation of fuel and power)

Date: 05/04/12

HBF 2012 consultation on changes to Part L (Conservation of fuel and power)

Dear member

We have been giving careful thought to all the feedback we have so far received on the Part L 2013 consultation. (The consultation closes on the 27th April 2012)

This is a difficult consultation for HBF to respond to – not least because it is double barrelled involving

  1. A proposed 8% increase in Part L requirements 
  2. A proposed new quality assurance/ penalty scheme designed to help tackle the perceived gap between designed and actual performance.

Given HBF’s commitment to working with Government to deliver the zero carbon homes policy from 2016 our response needs to be consistent with our generally constructive approach on this major programme. However, many of you have expressed understandable concerns about any change to Part L requirements in 2013.

There are a number of reasons for this – the lack of wide experience so far in building to 2010 requirements, the inadequacies of SAP including the input data from suppliers and manufacturers and concerns about cost.

If we do argue for no change in 2013 this still leaves us with the question of how we respond on the proposed approach to tackling the design v as built performance issue to which the Minister, Andrew Stunell, personally attaches great importance.

To help us think through our approach we have held two dedicated meetings recently – one on Part L itself and one on the design v as built question.

Taking the results of these meetings into account, we believe it is sensible to start our response on Part L by setting out our views on how the design v as built performance issue can best be tackled. This would create a positive context and address the issue that may well be of most interest to the Minister. 

The view of our meeting on the design v as built was, that the proposed PAS scheme mentioned in the consultation would be a blunt, ineffective and costly/time-consuming approach. The meeting concluded that a ‘improved alternative’ would be to move towards a focused and systematic approach to gathering the data on the performance of a number of dwellings built to current regulations.

On talking about the perceived gap between designed and actual performance the Government itself within the consultation ‘acknowledges that the available evidence is based upon a relatively small number of detailed scientific field studies’

We know that this evidence is based on research which is some years old.

An ‘improved alternative’ would identify the true cause and size of any performance gap and measures can then be put in place to reduce this. This work could examine the process beginning with the effectiveness of the SAP at the design stage right through the build process to the completion of the dwelling.

We would welcome your views on whether you would support us putting forward summary proposals on these lines to DCLG as an ‘improved alternative’ to the proposed PAS scheme being suggested in the consultation.

Subject to that, it would then be more credible for us to argue for no change in the 2013 consultation for the reasons indicated above which of course are reinforced by the reality that if there is an as built performance gap it would be potentially counter-productive to move to regulations based on the minimum FEES standard for 2016 at this stage. It is entirely possible that the combined effect of the work necessary to improve SAP and to close any design v as built gap may result in a different performance level for FEES in due course and so unhelpful to builders and the supply chain to seek to optimise design now around a standard that could well change again in any case.

If members feel that this might be too strong a position however, we might potentially offer a fallback option that was considered on a contingency basis by the recent member meeting on Part L

This alternative is based upon the Interim FEES Level recommendations of the Zero Carbon Hub , which has been adopted within the Code for Sustainable Homes 2010 Technical Guidance  as being equivalent to the FEE credits sought in Ene2 for Level 4.

As proposed by the UK Government the TER should be calculated in line with the methodology set out in the SAP 2012  consultation and based upon achieving the Interim FEES Standards of:

  • Apartments and Mid Terraced Homes = 43 kWh/m²/yr
  • End Terraced and dethatched home = 52 kWh/m²/yr 

Once the TER is set then house builders should be allowed to achieve the TER in any way that they feel is appropriate and there should be no requirement to achieve an absolute FEES target. In reality the majority of house builders will choose to achieve the TER using fabric only as this is likely to be the most cost effective route.

Below is a link to Section two - Annex B response form 2: New build standards and performance standards for works in existing buildings.

Question 28 deals with the proposed increase in Part L requirements and Questions 44 – 50 deals with the design v as built aspects.

We would be most grateful for your views on these possible approaches and options and indeed for any other options you think should be considered Wednesday 18th April 2012.

Dave Mitchell
Technical Director