Applying a Croydon-style design rulebook to densify suburban areas could increase housebuilding by nearly 6,000 additional homes per year on small sites, based on evidence from Croydon’s ‘experiment’ with its Suburban Design Guide (SDG) between 2019-22, Centre for Cities says.
The number of homes built on small sites in Croydon doubled during that period compared with the previous five years, as the SDG facilitated redevelopment of large detached single houses into small 3-storey blocks of up to 10 flats. While the policy was in place, Croydon delivered more of this type of development than any London borough has since 2004 (when records began).
If every Greater London borough adopted a similar SDG, Centre for Cities estimates net housebuilding on small sites would increase from 4,500 to 10,200 per year – accounting for variation in local conditions like land supply and house prices.
Achieving this would entail the redevelopment of 1,000 out of 525,000 suitable sites in Outer London boroughs – or less than one in 500 – per year.
Centre for Cities proposes that every London borough should use existing powers to introduce its own Suburban Design Guide.
It also proposes:
- The Mayor of London should set small site targets for local authorities and mandate that London boroughs use SDG-style policies for densification in the next London Plan. This recommendation is also relevant for metro mayors outside of London, as they develop their Spatial Development Strategies.
- Government should proceed with plans for more national planning rules, particularly for urban densification, as proposed in the draft NPPF currently in consultation.
- The Planning Inspectorate should use Croydon’s experience to inform assessments of local authority plans to meet their small sites targets.
Andrew Carter, Chief Executive of Centre for Cities, says: “Planning reform is at the centre of the Government’s strategy for increasing economic growth. London illustrates why this is the right approach. London isn’t building enough new homes to grow its economy, and new supply is falling.
“Croydon’s experience shows that rules-based planning reform works. The Mayor working with the Boroughs should introduce Croydon-style suburban design guides across London to deliver an immediate boost to supply.
“If we are going to build 1.5 million homes in this Parliament and sustain more housebuilding in and around big cities where homes are needed most, we need to use every effective planning measure we can.”
