The DCLG has recently laid out their plans for the 2013 Part L revision at a meeting which included approximately 60 representatives of trade associations and other stake holders. The agenda was set out as a fine balance between budget constraints, the drive towards zero carbon, the desire to stimulate growth and the current administrations' deregulation aims.
In economic terms it is a no brainer; their assessment is that the benefits at approximately £39 billion, out-way the costs by a factor of 2. They are very keen to obtain feedback and evidence on both benefits and costs as well as ideas on improved compliance and deregulation - what is not needed?
The Zero Carbon Hierarchy - stepped progress towards a workable definition. Image from Zero Carbon Hub (click image to zoom)
The hierarchy beginning with energy efficiency up to allowable solutions is still the underpinning of thinking as is the understanding of the need to address the existing building stock.
The time line is challenging - the Zero Carbon Hub and AECOM are working on proposals for dwellings and non-dwellings respectively. There will be working groups set up to meet twice between now and July that will address Dwellings, Non-dwellings, Retrofit with The green deal (joint with DECC) and Compliance with performance. The findings will go to the Building Regulations Advisory Committee (BRAC) in July and it is hoped to produce a consultation document for Ministers to consider between in October and December. The consultation will be carried out in Spring 2012 with the aim of publishing the new Approved Document in October 2013 coming into force in April 2013.
The work already underway is looking at whole life costs and there is considerable concern about how to close the gap between design predictions and performance in use. Some of the current thinking in non-dwellings is to increase airtightness targets to 3 m3/m2/hr @50 pa (as little cost involved); lighting to 75 lumens/W (fewer fitting s but what about uniformity?); and to move U values below 2.0 W.m2/k would be very expensive relative to the benefits.
The thinking on dwellings includes a flat versus aggregate approach recognising differing house types will have different energy signatures; moving to an interim Fabric Energy Efficiency Standard (FEES) specification that includes airtightness moving towards 5 m3/m2/hr @50 pa and updating SAP.