Croydon's Planning Experiment Could Transform London's Housing Delivery
A groundbreaking report from the Centre for Cities think tank reveals that implementing Croydon's innovative small-scale development model across London could generate approximately 6,000 additional homes annually. This comes as Mayor Sadiq Khan faces the formidable challenge of delivering 88,000 homes each year throughout the next decade to address London's persistent housing supply crisis.
The Suburban Design Guide: Croydon's Blueprint for Growth
Between 2019 and 2022, Croydon conducted a pioneering planning experiment known as the Suburban Design Guide (SDG). This rules-based approach, developed as an interpretation of the existing Local Plan, fundamentally transformed development possibilities across the borough.
The SDG established clear parameters allowing developers to replace detached housing with new residential blocks, subject to specific constraints:
- A strict three-storey height limit, extending to four storeys on corner plots
- Streamlined approval processes reducing discretionary refusals by planning officers
- Encouragement of applications through transparent, predictable guidelines
This framework proved remarkably effective, with small-site housebuilding doubling during the SDG period compared to previous years. The transformation was primarily driven by 6-10 unit new build developments that replaced existing bungalows and two-storey homes with three-storey apartment blocks.
Financial Viability and London-Wide Potential
The Centre for Cities analysis indicates that Croydon's approach remains financially viable across London despite current construction cost pressures. Redeveloping detached houses into nine-unit apartment blocks could deliver approximately 20 per cent profit margins in every London borough, according to their calculations.
Maurice Lange, an analyst at Centre for Cities, emphasised the importance of coordinated leadership: "Within the existing British planning system, it is very difficult for individual authorities to go it alone. Mayors need to serve as the referees for local authorities to implement SDG-style policies."
The think tank identifies around 500,000 suitable sites for this type of redevelopment across London, with particular concentration in outer boroughs including Barnet, Havering, Hillingdon and Bromley - each containing over 30,000 potential sites.
Projected Impact and Implementation Challenges
If successfully replicated across the capital, the Croydon model could dramatically increase construction activity:
- New build 6-10 unit developments would rise from 1,350 to 7,000 annually
- Overall small-site housebuilding would increase from 4,500 to 10,200 homes per year
- This represents a net gain of approximately 5,700 additional homes annually
The report acknowledges that local variations in land supply and house prices would affect precise outcomes, but maintains that the fundamental approach remains applicable throughout London.
Political Leadership and Future Planning
The research highlights the crucial role of mayoral leadership in coordinating borough-level implementation. Croydon's ability to remove the SDG after achieving its targets underscores how strategic planning at the city level can balance risks and opportunities across different local authorities.
A spokesperson for the Mayor of London responded positively to the findings: "The Mayor will always prioritise getting as many affordable homes built as possible and we welcome this report from the Centre for Cities as we consider the next London Plan, which will maintain high but proportionate design standards."
The statement continued: "As part of the plan a range of options for delivering more homes on small sites are being considered. This will help to unlock new high-quality homes and give Sadiq stronger levers to approve homes, as we work closely with councils, partners and others to boost delivery including on small sites."
This research arrives at a critical juncture for London's housing strategy, offering evidence-based solutions that could significantly accelerate delivery while working within existing urban frameworks. The Croydon experiment demonstrates how targeted planning reforms can unlock substantial housing capacity without requiring radical changes to London's fundamental development patterns.
