London’s mayor Sadiq Khan must do more to promote off-site manufactured (OSM) homes to help meet his housing delivery targets, a report issued by the London Assembly says
The study, released today, says that OSM has failed to take off due to demand, supply and funding issues, plus the absence of a common design standard.
But it added that conditions are ripe to make the case that OSM can help bridge the gap between what traditional housebuilders can provide and the mayor’s target of 50,000 new homes a year.
Assembly Member Nicky Gavron, the report’s author, said: ‘These buildings are high-quality and outstanding in terms of performance. Their construction is more environmentally friendly than traditional construction methods and they are a far cry from their prefabricated predecessors.’
The report called on the mayor to adopt a manufactured housing design code to drive a more standardised and aggregated approach.
The code would be developed with architects, manufacturers and housing providers, building on current thinking from the UK and Australia, the report said. It should be branded as a mayoral ‘kite mark’ supported by warranty providers to promote its use.
In addition, the mayor should remove any policy barriers to wider adoption of OSM homes, focus specific funding on the sector and set up an OSM-led procurement framework.
Off-site manufacture has been adopted in projects by major architects, such as Rogers Stirk Harbour + Partners’ PLACE/Ladywell, London Borough of Lewisham, London. The firm, in a written submission to the report authors, said that ‘in comparison [between] traditional schemes versus offsite […] offsite wins hands down in every way’.
Mark Farmer, chief executive of construction firm Cast Consultancy, said: ‘This timely report sends an unequivocal message to the Mayor of London that now is the time to show strong political leadership to establish a mainstream precision manufactured housing market in the capital. It could underpin ambitions not just for housing, but wider economic growth.’
For too long the approach of policy has been focused on isolated factors dragging on housing delivery. In this report, an essential companion to the Farmer Review, the London Assembly Planning Committee draws together a number of significant competing factors to be addressed as a whole to solve a complex problem, including the potential collateral damage to our communities and our environment that meeting London’s housing demand may incur.
By building off-site we minimise noise and disruption to neighbours, we reduce vehicle movements and we ensure quality, efficiency of cost and speed.
In tandem, by building in mass timber, as many of the case studies in the report do, we reduce carbon emissions via reduction in embodied carbon and enable denser, taller buildings on brownfield sites over transport infrastructure by building in lightweight materials.
We support Nicky and her team in their approach to embed this firmly in policy with the Mayor’s support. The Mayor’s recent Supplementary Planning Guidance on Affordable Housing and Viability offers rewards to teams who deliver projects to exemplary standards by permitting increased density.
Policy should also recognise these benefits of reduced embodied carbon, speed, quality and neighbourliness offered by off-site manufacture in the consents we negotiate with our partners in the planning department and in tandem with the ambitious sustainability targets already set for carbon emissions in use.
Andrew Waugh, director, Waugh Thistleton
Having a standardised design code will increase familiarity, lower barriers to entry for manufacturers and de-risk financing through advocating a design approach that unleashes the full potential of offsite technology. This means revisiting some guidance in the existing London Plan in terms of apartment building design, which just isn’t suited to optimising offsite technology. With strong strategic leadership, the mayor can ensure we get the most out of this exciting opportunity.
Rory O’Hagan, director, Assael Architecture