A small housing site can still face an affordable-housing contribution under a council's published policy; fewer than ten homes is not a safe London-wide answer. Check the current national policy, the local requirements, the way the homes are counted and whether the proposal calls for homes on site or a justified financial contribution. Richmond's adopted March 2026 guidance is an example of published small-site requirements. [1]
Start with the current national policies
The NPPF published on 17 August 2026 uses HO5 for plan-making on the needs of different groups and HO8 for providing affordable homes. HO5 addresses affordable-housing requirements for major development and allows requirements for non-major residential development in Designated Rural Areas. HO8 addresses meeting up-to-date development-plan requirements and the circumstances for off-site delivery or a cash contribution. [2][3]
The NPPF glossary defines major housing development as ten or more homes, or a site of 0.5 hectares or more. Do not use the phrase “small site” without identifying the definition relevant to the policy being applied. A low dwelling count and a small site area are different tests. [4]
Read the actual borough policy
Richmond adopted its updated Affordable Housing SPD on 26 March 2026. It explains Policy 11 of the borough's Local Plan and identifies small sites as those capable of fewer than ten dwellings on a gross, rather than simply net-additional, basis. It describes contributions according to the proposal, including new build, conversion and loss of employment floorspace. [5][1]
This is a description of Richmond's published approach, not a contribution tariff for all London boroughs. Its SPD predates the August NPPF. Where a small-site contribution is proposed, ask the council to identify the precise current policy basis and explain how it has applied the newer national policy to the case. Do not assume either that the older local requirement automatically disappears or that its application to every new proposal is settled. [1][3]
On-site homes and cash contributions are different
HO8 expects applicable affordable-housing requirements to be met on site unless its grounds for off-site provision or a cash payment are satisfied. A cash payment therefore is not simply a developer's unrestricted choice instead of affordable homes. Its calculation and delivery arrangements need to be agreed in the planning process. [3]
For the budget, establish the relevant unit count, tenure requirements, valuation or formula, any review mechanism and the proposed payment trigger. Ask for a written calculation rather than multiplying a percentage by whichever property value is most convenient. Richmond's guidance sets out a specific small-site calculation process; another council may use a different adopted approach. [1]
Viability and other charges
A viability case needs evidence. Current NPPF DM5 says that the price paid for land is not a justification for failing to meet the relevant policies, and that assessment inputs and departures from plan-stage assumptions must be explained. [6]
Affordable housing is also distinct from CIL. Keep the affordable-housing contribution, borough and Mayoral CIL, and any other mitigation separately identified so the combined development budget is visible. [7]
Changes requiring a fresh check
London's 25 March 2026 housing package includes a conditional temporary route with different affordable-housing thresholds for qualifying schemes. It is not a universal small-site exemption or automatic release from an existing obligation. The draft new London Plan may also change future requirements if adopted. Check eligibility and the current policy before relying on either. [8][9]