Post Hill Social & Affordable Housing
Client: Mid-Devon District Council
Treated floor area: 5516 m2
The development is a low rise social and affordable housing scheme of 70 homes across 29 buildings, including terraces, semi-detached and detached houses and two small apartment blocks.
Delta Q were brought into the project by Faithful & Gould once it was decided to target Passivhaus Certification. After an initial review the preliminary designs underwent wholesale change to optimise energy performance as well as meeting site constraints such as topography and the relationship of the adjoining developments. Overall, there are 29 separate buildings, each of which will be certified to the Passivhaus Classic standard.
Our role was to assess the requirements to meet Passivhaus across all buildings using the same U-values and develop preliminary construction methodologies for timber frame and masonry. Due to space constraints, most of the homes have Zehnder 180 MVHR units which are small but at the lower end of heat exchanger efficiency for Pasivhaus – this put pressure on the rest of the fabric design, so special attention had to be paid to ensuring that all buildings would pass.
Managing multiple similar buildings within PHPP was a major challenge, so we used the PHPP Variants tool to test designs and compare the performance of similar buildings. We enlisted the help of e-Mod Studio to undertake some of the modelling as this was undertaken at a particularly busy time. Working with Saunders Boston Architects we developed a number of key details and undertook thermal bridge analysis using Psi-therm to calculate ψ-values for key building junctions.
Delta Q also assisted with development of Passivhaus specific Employers Requirements for the tender.