The LETI network has published a guide that outlines the best practice for energy use intensity (EUI) modelling.
The LETI Operational Modelling Guide supports clients, project teams and modellers to “work together on the critical analysis that will monitor and inform progress towards a net zero building in operation”.
Among LETI’s seven key recommendations for EUI modelling is the use of the CIBSE TM54 methodology. The guide says TM54 should be used as the central methodology for all energy performance assessments, including energy performance modelling, in all building types.
LETI recommends that the TM54 implementation matrix is used to monitor the confidence and its variance in the input data. The confidence level attached to most of the key modelling inputs should reach ‘high’, the guide states. A detailed risk management plan should also be discussed and agreed with the project team. This plan plays an important role in managing the risks that could take a building’s energy use over the target. Furthermore, the plan should include advice on how each risk is to be mitigated.
Collaboration and information exchange also features. “The construction industry [should] become more open to the simple sharing of energy model files through the design process in the same way that drawings or specifications allow the transfer of design information between existing and new team members.”
Operational phase reconciliation
LETI’s recommendations also address the post-handover/operational phase of a building: “Once metered data has been collected from the building, this [should be] compared against the estimated EUI/energy consumption of the building. This is essential to close the performance gap [between design and actual].”
The guide also features an 11-point roadmap.
LETI founder and Introba associate Clara Bagenal George said: “As an industry, we need to move away from only doing compliance modelling. We need to fully embrace energy performance modelling and the improved building performance that it can enable.
“We will not meet our climate targets without this shift. Performance modelling must be carried out, so that design teams and developers and contractors have the tools to design and construct buildings that meet net-zero energy targets.
“This will require major upskilling of energy modellers and more engagement with modelling from the wider built environment community. This guide provides the textbook for this.”
LETI was founded in 2017 as a voluntary network. It now has more than 1,000 volunteers from across the built environment.
Don’t miss out on BIM and digital construction news: sign up to receive the BIMplus newsletter.