Part L 2010 is off the starting block

Part L 2010 comes into force tomorrow, 1 October. It brings with it a further 25% reduction in theoretical carbon emissions.  Due to the relaxed transition period allowed, it is unlikely that building control bodies will be flooded with Building Regulations applications to the new tougher standards for some time yet. However, software needed to demonstrate compliance is now available. This means that the industry can at last see the full implications of the new regulations by seeing how their house designs perform in approved software, and indeed submit Part L 2010 design submissions if they so choose.

Dyfrig Hughes, Technical Manager for National Energy ServicesDyfrig Hughes is Technical Manager for National Energy Services, the providers of NHER Plan Assessor software. Discussing the changes, he said: “Part L1A 2010 brings with it big challenges for the housebuilding industry. The requirement to at least seal cavity party walls, and most likely insulate them too; the need to start paying more attention to the thermal detailing of junctions between walls, roofs, floors and windows. More homes will need pressure testing and boilers will perform worse in SAP 2009 that they did in SAP 2005. With the release of our SAP 2009 based NHER Plan Assessor 5.0 software, housebuilders can now get some certainty about how their designs will perform to the new SAP 2009 and Part L 2010.”

To coincide with the start of the new Part L, Communities and Local Government (CLG) have issued conventions for how SAP assessors should go about gathering data to enter into SAP software for producing building regulation submissions and Energy Performance Certificates. The aim is to bring more consistency to the process. For example, before accepting a U value, an assessor either needs to calculate the U values themselves, or check that the U values provided by someone else are calculated correctly or have been produced by someone accredited. Clarification is also provided about how to deal with thermal bridging calculations when not all the information is available; for example, if a developer has used Accredited Construction Details for some junctions but not others.

Dyfrig Hughes also sat on the CLG working group that developed these conventions. He added: “CLG is very concerned about the gap between the carbon emissions estimated in a SAP assessment, and the actual carbon emissions indicated by research into how homes perform when they are built. The issuing of these SAP/Part L conventions by CLG for all SAP assessors to apply is a milestone in the attempt to tackle this issue, in that it will help to bring rigour and consistency to the assessment process. However, this is one tiny step in a process that also needs to ensure that homes are actually built to the specification assumed in the Building Regulations Submission. Part L 2010 has started to engage with these issues that need to be tackled head on if we are to have any chance of meeting the Government’s zero carbon target for new homes by 2016”.

NHER Plan Assessor 5.0 is currently being issued to members of the NHER Accreditation Scheme. You can read more about Plan Assessor, how to become an On Construction Energy Assessor and how to join the NHER Accreditation Scheme. NES also offers online CPD designed to give assessors a thorough understanding of the new SAP and Part L.

Screenshots from NHER Plan Assessor 5 (Click to enlarge):