An updated 2018 version of BREEAM New Construction is due to be launched early next year and the BRE recently consulted with industry on the DRAFT manual. IES has reviewed the documents and provided feedback to BRE in particular on the Energy Credit Ene01 and the DRAFT Guidance Note (GN32) which outlines the proposed approach for the detailed energy modelling criteria in Ene01.
Over the years, IES has and still is heavily involved in software development for UK compliance and BREEAM as well as other global rating systems such as LEED. We’ve worked with Green Building Councils all over the world to help create Certification Engines within the IES Virtual Environment (IESVE) that are approved for compliance with relevant rating systems.
However, we feel strongly that in order to tackle the energy performance gap and ensure that energy efficient design intent is followed through into operation, the role and use of virtual simulation tools in conjunction with an integrated design process needs to be more strongly encouraged by the BRE within BREEAM NC 2018.
This includes energy modelling during design of the actual building and not just an NCM compliance model that misses out non-regulated energy use. Non-regulated energy use actually makes up a large proportion of the performance gap – its energy use that designers know the building will have, but which doesn’t need to be accounted for in NCM calculations for compliance and EPCs.
Our main concern is that while the GN32 strategic approach appears to incentivise more detailed energy modelling and reward accurate predictions of energy, there is still an over reliance on NCM methodology and data. We recommend that GN32 eliminates any reference or consideration to ‘default to NCM data’. Giving project design teams the fall back on NCM data will lead to pressure to take the ‘easy option’ that inevitably devalues their analysis and will help to keep the performance gap alive.
The use of UK Compliance calculations for accurate energy assessments has already been widely discredited as not being an accurate prediction of in-use energy. We suggest encouraging designers to move away from the use of compliance calculations towards a more robust analysis method (e.g. ASHRAE 90.1) which could be used to attract (say) twice as many credits, mindful of the fact that BREEAM is always seeking for credits to go beyond the industry ‘norm’.