Analysis of UK domestic building retrofit scenarios based on the E.ON Retrofit Research House using energetic hygrothermics simulation – Energy efficiency, indoor air quality, occupant comfort, and mould growth potential

Publication date: December 2013
Source:Building and Environment, Volume 70
Author(s): Matthew R. Hall , Sean P. Casey , Dennis L. Loveday , Mark Gillott
The work forms part of the CALEBRE project (2008–2013), the aim of which was to investigate a suite of technologies and staged approaches for retrofit upgrades for ‘hard-to-treat’ solid/thin cavity masonry-walled UK domestic buildings that would i) reduce operational energy demand/carbon emissions, and ii) be acceptable and appealing to the building occupants. The E.ON Retrofit Research House (Nottingham, UK) was used as an instrumented test platform as part of this study. The retrofitting phases (and technologies) have been used as the basis for the modelling methodology in this paper, together with the corresponding envelope assemblies, material properties, climate, and internal load parameters. The approach to retrofit was to increase air tightness (reduce ACH), decrease static U-values of the external envelope (wall, floor and glazing), and upgrade heating system efficiency. This was complemented by a combination of options that included a whole-building system of mechanical ventilation with heat recovery (MVHR). These interventions were analysed alongside simulated passive buffering of variations in indoor air psychrometric conditions using conventional (clay, timber) and advanced (mesoporous silica) wall surface treatments. Each retrofit scenario was modelled using an energetic hygrothermics building performance simulation (BPS) approach to determine the combined effects of retrofit packages on indoor air psychrometric conditions, external envelope (dynamic) heat transfer, operational energy efficiency, occupant comfort, and mould growth potential. It is proposed that this approach can provide the basis for an intelligent risk management strategy to inform both the design and deployment of retrofit upgrade packages intended for residential buildings.