Nearly-zero energy buildings: retrofitting to meet the standard

Executive summary This document presents a method for applying the nearly-zero energy building (nZEB) standard to existing UK commercial and residential buildings. The findings presented are based on analysis supported by dynamic simulation modelling of UK buildings, aiming to demonstrate the potential benefits but also highlight the risks associated with achieving such high energy-efficiency standards within the built environment. This work builds on that presented in TM55: Design for future climate — case studies (CIBSE, 2014). Four case studies are utilised to explore what it means to achieve the nZEB standard and apply it to existing UK buildings. These have been presented individually within this publication to focus on the various outcomes of each building type. The highlighted outcomes demonstrate that with well thought-out design decisions and careful consideration of a building’s resilience to a changing climate, the standard can be achieved — and this can introduce long-term cost and energy benefits. There is a large amount of work that needs to be done, and many questions to be answered, before fully transitioning to nZEBs