Uttoxeter, Bungalow Retrofit
Project Overview
Background
Trent & Dove Housing provides affordable homes across East Staffordshire, South Derbyshire, and North West Leicestershire. It owns and manages around 6,500 properties, ranging from family homes to sheltered accommodation. It has also sometimes collaborated with Wychavon District Council on schemes designed to improve the energy efficiency of the local authority’s social housing.
This £1 million project was one such collaboration, featuring 34 occupied bungalows in Uttoxeter. An important element of the multi-measure project was the installation of an external wall insulation (EWI) system, designed and supplied by Permarock. It would run concurrently with another scheme in Birmingham, also featuring Permarock systems.
Brief
The project was to be part-funded by the Social Housing Decarbonation Fund (SHDF) Demonstrator phase and would be delivered by a Trustmark-register installer, in accordance with the requirements of the PAS standards. It would be a multi-measure scheme featuring EWI, loft insulation, and the replacement of exterior doors and windows.
Design and Specification:
Permarock technical staff undertook property-by-property inspections and retrofit assessments, as demanded by best practice and the PAS standards. They also conducted pull-out tests on the various substrates, and supported the stakeholder team with system specifications, drawings and detailing.
The bungalows had been built to a Crosswall design, with cavities in the party and gable walls. They feature in situ concrete lintels at eaves level, and block and brick infill. The cavities have a nominal width of 50-70 mm, and had been injected with PU foam. However, the client wished to further enhance their thermal performance. The installation of an EWI system would mark an important step towards improving that performance, especially when supported by the other measures.
The system design had to take account of the fact that the properties are set on a slightly sloping site and were constructed in pairs, staggered vertically and horizontally. Consequently, stepped details were required. Again, our technical support team provided the necessary assistance with designs and detailing.
For this scheme, the client chose a system based on Permarock Mineral Fibre insulation. Permarock Brick Effect Render would be applied over the top to protect against the weather and to produce an attractive, hardwearing finish.
System Characteristics
Permarock Mineral Fibre external wall insulation incorporates non-combustible stonewool insulation and is suitable for installation on all building types including high-rise. Its thermal conductivity is 0.036 W/mK and, when forming part of a suitably designed system, it enables very low U-values to be achieved. It is suitable for schemes that seek to meet or exceed Passivhaus standards.
It is compatible with all Permarock renders and finishes. For this scheme, it was combined with Permarock Brick Effect Render throughout. Permarock Brick Effect Render can be used to replicate the appearance of a wide range of brick colours, textures and sizes, and its water-repellent finish helps it to retain a clean, attractive appearance.
Installation
The work took place between 2020 and 2022 and, with support from our technical team, the installation progressed steadily. Permarock staff delivered several training sessions for the Retrofit Installer operatives and made weekly site visits to provide support and to carry out quality checks, as required.
The parallel work stream in Birmingham also proceeded according to plan, despite the complications arising from the latter stages of the Covid pandemic. Here, too, our technical staff provided on-site support that helped to speed the pace of completions.
Result:
The work was delivered on schedule, all in accordance with the PAS standards.
Notably, during the installation, the site was visited by a fact-finding delegation comprising representatives of BEIS, TrustMark, Savills and other bodies. They inspected the Vicarage Road site in Stramshall to gauge progress. They commented positively on the management of the project, the appearance of the finished properties and the feedback they had received from residents, who said that they had been impressed by the effects of the various measures.
After the visit, the client reported that the consumer advice organisation Act On Energy had maintained contact with local residents, whose feedback had been “overwhelmingly positive.”
Client
Trent & Dove Housing / Wychavon District Council
Specifier
Sustainable Building Services (UK) Ltd
Substrate
Cavity Wall
System
Permarock Mineral Fibre External Wall Insulation Systems
Finish
Permarock Brick Effect Render
