Whole House Retrofit, Penistone, South Yorkshire.
This project is a rigorously evidence based whole house retrofit of a 1948 built cavity wall semi-detached house. The foundation of the project was an in-depth energy report produced at RIBA Stage 2. This collated existing energy use data from bills, which were used to define baseline energy use and carbon emissions for the house, and in turn validate a corresponding “as existing” thermal model. Iterative modelling then defined an optimal approach to building fabric improvement to improve energy efficiency by 65%, with a predicted consequential leap in thermal comfort. This then informed the subsequent design and specification, which conceptually is based on a fabric first strategy – significantly improved insulation and air-tightness – with the installation of an MVHR system to provide energy conserving cold season ventilation.
The retrofit utilises low embodied energy materials, for example woodfibre and lime render external wall insulation to upgrade the existing walls, and timber framed construction to the new build elements. An interesting feature – which is more for horticultural and pleasure use than an integral part of the building energy strategy – is the attached greenhouse / winter garden element to the rear of the house which will be built in phase 2. Phase 1 of the project is now complete and its performance will be analysed against design predictions.
Details
Design: 2019-2020
Planning Consent: October 2020
RIBA work stages: 0-7
Construction (phase 1): 2021-22
Project Team
Structural Engineer: Martin Evans Associates
Quantity Surveyor: TJ Marshall Consultancy Ltd
MVHR supply and design and windows / doors: Green Building Store
Main Contractor: SL2