KJ Tait

Design for Performance - Thoughts

24 August 2022

Design for Performance – More than a modelling exercise


We have recently submitted our first Design for Performance (DFP) to the Independent Design Reviewer. The experience of undertaking this and the work involved in six other DFP projects we are working on has shown that the scheme is a robust process for ensuring design completed at RIBA Stage 4 is carried through to Stage 5. With the Building Energy Simulator still on board during Value Engineering, the Simulator can run any potential changes to fabric or HVAC design and assess what affect any change would have on the NABERS Target Rating. The risk of the NABERS Target Rating reducing may change this process for the better, thus ensuring that Stage 4 designs make it through to construction.


Through the Rating Achievement Plan, the document that plans for how the NABERS Target Rating will be achieved in-use, aspects we are incorporating include ensuring a Soft Landings process is implemented at Stage 6 so that the building’s occupants are aware of how to use the building. For example, our first DFP building uses the windows in a mixed mode approach; the occupants need to be aware of when to open the windows to provide free cooling. For the building in-use, we are implementing a monitoring regime to check the monthly billing against what was predicted within the modelling. This will include assessing the BMS on a quarterly basis, to ensure that no changes have been made which alter how the building was intended to be used.


Whilst advanced energy modelling is at the heart of the DfP, the ability of the Design Team to be onboard through the first year in-use is important if we are serious about reducing carbon emissions and closing the ‘Performance Gap’.