We have also started work to develop a national strategy focusing on greater use of offsite construction. This work is being jointly led by the Scottish Government’s More Homes Division and the Scottish Futures Trust and is supported by a wide range of partners including the Construction Scotland Innovation Centre, affordable housing sector leaders, various departments of the Scottish Government, Enterprise Agencies, industry, Homes for Scotland, designers, Zero Waste Scotland, Edinburgh Napier University and others. We aim to publish the strategy in late 2021 and it is likely to include a short-term objective of achieving zero emissions from 2024 (or sooner) and a longer term objective of achieving net zero new affordable homes based on their full life cycle.
In Scotland, most homes (approximately 85% across all sectors) are built using timber kit systems – this is much higher than the rest of the UK and gives us a strong platform upon which to build. While we continue to see timber-based systems as the way forward, most of those systems are open panel systems where most of the construction of homes takes place on site rather than in the factory. We therefore believe that future strategy should, to begin with, be based on moving to more advanced timber systems – most obviously closed panel systems, whilst continuing to encourage the adoption of other innovative systems in the longer term.
Through the above research, and our work developing the strategy so far, most housing practitioners have expressed concern about moving to volumetric systems at the current time because they believe that they are insufficiently tried and tested. Indeed some have negative experiences of such systems although it is recognised that, as technologies advance, confidence in volumetric and other innovative systems is likely to increase. No such concerns have been expressed however about either open panel or closed panel systems, both of which are considered to be ‘business as usual’.
In order to encourage a shift in approach, we are likely to adopt ‘pre-manufactured value’ (PMV) as one of a range of key performance measures in the forthcoming net zero/ offsite strategy. PMV is a measure of how much construction is done in a factory setting rather than on site. The higher the PMV, the higher the likely capture of the benefits of greater use of offsite construction benefits will be. We will therefore baseline the PMV of systems currently used in affordable housing and discuss with partners an appropriate future target.
We also believe this approach will support the improvements needed to the fabric of homes in order to support zero emissions heating and future net zero affordable homes to ensure that new homes are affordable to heat.
Other key features of the national strategy are likely to include:
- making greater use of Scottish timber
- re-shoring of appropriate supply chains to increase resilience and maximise economic benefits
- contributing to the wider green economic recovery
- measures to strengthen the adoption of Fair Work principles
- progressing circular economy construction principles
- working with design partners to develop the strategy so that it further embeds place principles to create successful and vibrant communities, and
working with partners to encourage a more diverse workforce based on a manufacturing and digitally enabled affordable housebuilding industry.