Timber Offsite MMC Living Lab
Following a presentation at the International Retrofit Conference 2025, Okana shares new research into retrofitting UK houses to achieve net zero emissions, using a case study of a UK mid century bungalow retrofit.
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Dr Jon Stinson
Associate
Dr Ruth Saint
Associate
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January 26, 2026
Abstract
The built environment, particularly ageing housing stock, significantly impacts the global energy consumption and energy related carbon dioxide (CO2) emissions. Retrofitting these dwellings, particularly in the UK due to its aging housing stock, is a critical step towards reducing environmental impacts and achieving net-zero emissions.
This case study adopts a “living lab” approach to investigate the phased renovation of an early 1950s bungalow in Edinburgh conducted over two phases (2011–2017 and 2021–2023). The extension and fabric upgrade measures have utilised an array of offsite and innovative Modern Methods of Construction (MMC) approaches including the 1st retrofit and extension application of UK-grown mass timber.
Phase 1, totalled in 10.8 tCO2e of embodied carbon emissions, while phase 2 resulted in 11.47 tCO2e. However, the combined offset emissions of both phases amounted −23.86 tCO2e when considering biogenic carbon storage. The property’s useable space area more than doubled from 91 m2 to 197 m2 and resulted in a 27 % reduction in total energy consumption from 19,782 kWh/year to 15,679 kWh/year. As a result, the property’s market value has increased by 70 %.
The findings provide an insight into using off-site timber MMC for the retrofit of existing dwellings and offer a replicable model for net-zero transition.
Related environmental and sustainability
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Measuring Mass Timber
