Retrofit Projects& case studies

After an initial PHPP energy model and retrofit plan made in 2015, this has been a slow-burn phased retrofit. The house already had had some improvements (triple-glazed windows, solar thermal and floor insulation) but still had a space heating demand of 178 kWh/m².yr and was not comfortable to live in. So far the garage has been converted (2018), kitchen refitted and made airtight (2020), and the rest of the house has been made airtight along with the installation of the MVHR system (2021). Future plans include external wall insulation, after which the space heating demand should have dropped to 63 kWh/m².yr.

Carried out the initial PHPP design and thermal bridge modelling as part of a retrofit plan with the aim of achieving EnerPHit (which is the Passivhaus retrofit standard). In the end this goal was achieved (where the project and actual certification was carried out by others).

This was to provide advice about what to do for non-functioning MVHR ventilation systems that had been installed in different flats within an apartment block. The building already had serious overheating problems in summer as it had been built with no openable windows (how is that possible!), and in addition several ventilation systems were not working and showing electrical faults which were probably because of the blocked filters. Remedying this involved finding out what exact electrical faults had occurred (determined by the sequence of LED flashes) and arranging repairs where needed with electricians, as well as changing blocked filters. The filters themselves were blocked due to a lack of maintenance on the part of residents, who had been given no information on what to do and how often to do it (namely changing filters).

This was a retrofit that was done in one go. Work included both the PHPP design, thermal bridge modelling and MVHR design, but also involved daily site project management as part of the retrofit contractor team on site over a period of several months. It is the focus of one of our case studies described here.

Created PHPP energy models for a phased retrofit – this included carrying out thermal bridge modelling to mitigate heat loss and condensation risk at the junctions.

A PHPP energy design along with thermal bridge modelling for junctions was done to inform decisions on how to tackle several areas as part of a phased / partial retrofit. So far work has included internally insulating several rooms as well as the loft, which has reduced the space heating demand by about 30%. For this project we were also acting also as project manager and contractor. Further retrofit work might be done in future.

Step by step retrofit which achieved Superhome status. Improvements included MVHR installation, which at the time was quite an unusual thing to try for a Victorian house. The building’s space heating demand was retroactively calculated using PHPP. This house ended up being registered as one of the SuperHomes pioneer projects which that aimed to provide a peer-to-peer platform to showcase retrofit to others considering doing something similar themselves. It is the focus of one of our case studies described here.