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Plot 9: Refurbished House

Retrofit Demonstration led by BRE Scotland with Edinburgh Napier University, Historic Scotland and Scottish Government

Plot 9, Refurbished House, required the developer to demonstrate innovative retrofit techniques and solutions. In Scotland we are currently replacing the housing stock at a rate of less than 1% per year. It is therefore imperative that we improve the performance of the existing housing stock, if we are to achieve the CO2 reduction targets mooted for 2020 and 2050. Refurbished House will provide a research base for how this can be done most effectively in the future and will provide valuable information on cost and performance of retrofit solutions. 

Client: BRE Scotland (ERACO STAR)

Lead Developer Cruden Building & Renewals

ERACO STAR Project Team and Funding Support: Edinburgh Napier University, Historic Scotland, Scottish Government

Design and Construction Team: Cruden Building & Renewals, Kraft Architecture, Edinburgh Napier University, Hannah Reed Consulting Engineers

BRE Napier logo HS logoScottish Gov logoEraco logo 

BRE Scotland will lead the development of Plot 9 on the Innovation Park as part of the European ERACO STAR project. This three country project (Belgian Building Research Institute, Passief Huis Platform, Belgium and Lund University, Faculty of Engineering, Sweden are European project partners) focuses on the technical refurbishment of typical dwellings in a Sustainable Thermal Acoustic Retrofit (STAR).

The ERACO STAR project aims to focus on 'real' sustainable renovation of dwellings considering the acoustic aspects alongside thermal properties.


In Scotland, one of the worst performing apartment building types BOTH thermally and acoustically is the '4-in-a-block' (where there are two flats on the ground floor, and two on the first floor). There are approximately 265,000 of these in Scotland alone, but their build style (1930's to 1970's) is similar to cavity block walls found in 3 million dwellings in England. These building types have the lowest sound insulation of any of the housing stock in Scotland.

In the UK, this STAR project will allow a representative '4-in-a-block' to be built (on Plot 9) and evaluated and benchmarked for diverse demonstrations of retrofit measures. One apartment of the four will remain unchanged, as a control, but the other three will be altered over 2x12 month cycles allowing at least 6 solutions to be evaluated.

The project will be able to fully identify embodied energy information and assess the cost effectiveness of fabric upgrades for this important building style, for walls, windows, roofs and services. Indoor air quality tests, air tightness tests, and acoustic testing will be undertaken as well as detailed thermal analysis from inbuilt thermal sensors, thermography and thermal modelling.

Project phases

Phase 1: Design and approvals - Current phase

BRE are working with Kraft Architecture and Hannah-Reed Consulting Engineers to create detailed drawings of the '4-in-a-block' test building. The design is based on historical references with input from Historic Scotland and North Lanarkshire Council. These drawings will form the basis of planning and building warrant applications.Atholl Plans and a section of the 4-in-a-block to be constructed can be downloaded on the right.

Phase 2: Construction

BRE will appoint a main contractor to oversee the construction of the test building. This will involve the completion of the building envelope using 'traditional' materials and to typical dimensions. External roof and wall finishes, and internal plaster will be provided. One of the four apartments (the control) will be fully finished with windows and external doors.

Phase 3: Retrofit design and delivery

Stakeholders will be invited to provide retrofit solutions for the three remaining apartments. They will be asked to provide detailed information on the approach and materials used,  and the predicted costs and performance to be achieved. BRE will evaluate the submitted solutions and select those to be demonstrated in the apartments.

Phase 4: Performance assessment and monitoring

Contractors identified by BRE and the individual apartment developers will install the chosen solutions. At this stage there will also be a focus on training in relation to the physical installation of innovative products and technologies within an 'old' existing building. After completing the refurbishment works, the performance of each apartment will be monitored for a period of up to 24 months.

 For more information please contact David Kelly at BRE Scotland (kellyd@bre.co.uk or 01355 576200). If you have a product or service you would like to demonstrate in the retrofit project please contact Katy Hunter (hunterk@bre.co.uk or 01355 576200).