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Strategic support for energy efficiency and sustainability

The stopping-off point

03/08/2011 19:52:35

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Zero carbon newbuild in 2016 – still Government policy, and a worthy aspiration.  But Cutland Consulting Limited believes that the less-heralded revision of Part L in 2013 provides the unique and vital regulatory stepping-stone to 2016.  “If we get the standard for 2013 right, then it will enable the industry to ‘practice’ its solutions early,” said director Neil Cutland.  “There are encouraging signs, but many organisations still seem to be overlooking the importance of 2013”.

As reported in a previous news story, Neil has been sitting on the Part L1 Working Group WG1, which is part of BRAC.  His involvement with that group has led him to two conclusions:

“Firstly, in my opinion the fundamental energy standard for 2013 should be set at the FEES level (the first slice of the zero-carbon triangle, ie. a space heating demand of 39-46 kWh/m2/yr depending on built form).  And that’s it!  No need for an additional carbon standard, because it’s implicit.  Let builders focus on achieving this pragmatic fabric standard without having to worry about other metrics initially, and in a couple of years they’ll be tremendously well-positioned to take the final step to 2016.”

“Secondly, I really want to see Passivhaus-compliant dwellings granted ‘deemed‐to-satisfy’ status in Part L1A 2013.  I don’t want to get a reputation for being a one-trick pony, but I’ve been a keen advocate of Passivhaus for many years, and I see widespread support for this suggestion within the industry.  The job now is to convince Ministers to keep the suggestion in the Part L consultation (which is due towards the end of this year), and obviously to lobby people to respond positively to that section of the consultation in due course.”

If you have strong views on these suggestions, either positive or negative, Cutland Consulting Limited would like to hear from you.  You can contact us via our website, by clicking here.


1.  Passivhaus performance is unquestionably in advance of any energy efficiency standard that might credibly be proposed for 2013, and it should also meet whatever carbon target is proposed, without the use of renewable devices.

We do not propose that Passivhaus replaces any existing methodology.  Passivhaus is a different approach to the ENE1 method used in Part L compliance.  Further detailed analysis of how the methods differ might be interesting, but is neither necessary nor particularly helpful in the 2013 context.

3.  Passivhaus is clearly a proven, robust, effective low-energy standard. There are c. 20,000 Passivhaus homes on the continent to date.

4.  The Passivhaus process without doubt improves the outcome (ie. as-built performance is much closer to design-stage prediction than is more normally the case).

5.  The whole cconcept of Passivhaus certification provides technical comfort and offers a significant

knock-on benefit for Building Control Bodies.  Passivhaus compliance is very clearly defined, a certification process is already set up in the UK, there is a competitive market, and the process is operating well.

6.  There are precedents for using alternative models in Part L2A, where a designer can use SBEM or the various commercial DSMs, interfaces and MCORs listed in DCLG’s “Notice of Approval…” (12 of them currently).  The Passivhaus Planning Package software is at least as complete and robust an energy model as the SAP.

7.  We recognise and accept the separate requirements to produce SAP ratings and EPCs, so there are no issues to be resolved there.  Ideally the software providers would provide import and export functionality to ease the process.

8.  The Passivhaus community is, quite simply, designing and building to this standard anyway.  The movement is gathering momentum.  Such pioneers should be encouraged, and given some small reward for going beyond the call of duty.

9.  In conclusion, ‘deemed-to-satisfy 2013’ status for Passivhaus is clearly appropriate.  We do not argue that this should replace other compliance routes, but that it could provide an entirely optional alternative route for its proponents.

4 August 2011


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