This definition has won considerable plaudits across the small and medium-sized (SME) housebuilding industry.

However, the definition also includes a maximum area measurement of one hectare area size, which SME housebuilders express as inappropriate because Local Planning Authorities (LPAs) already set locally acceptable density policies and the increasing policy and development requirements on land use, such as drainage, biodiversity, grid, sewerage, active travel, mean sites regularly go over one hectare.

The consequence of an area-based threshold is that many SMEs would miss out on the medium-sized site definition and its introduction of planning proportionality.

Michael Parinchy, construction manager at ProBuild 360 Ltd and HBA Chair, said: “With minimum densities, housing mix policies, and other obligations like BNG, highways, SUDs, etc., hectares or other area measurements are not a good metric to determine the site size category.

“For SMEs, the commercial viability of a development is calculated using plot numbers, so to use other thresholds and measurements would be a misunderstanding of how things work at this scale and counterproductive to the real-world activation of the SME housebuilding sector.”

In ‘Size ‘still’ Matters: Dwellings Matter NFB builds on its ‘Size Matters’ report 2025 – which introduced four site size thresholds alongside a seven-year campaign for a ‘medium’ sized site – to explain why its proposals did not include measured area thresholds and why the Government’s future consultation on a ‘Medium’ sized site should follow that lead.

Focusing exclusively on ‘medium-sized’ sites, ‘Size Still Matters’ explores:

• LPA responses to the NPPF consultation, which introduced the 1-hectare limit
• Whether the subsequent NPPF policy to support SMEs and smaller sites succeeded
• How Local Plans, supported by national policy, already shape locally appropriate dwelling per hectare (dph) levels.
• Explores how housing developments are giving over more land for non-residential needs, and why the land taken is increasing.
• What type of projects are most likely to benefit from the proposal as currently conceived.
• Why most SMEs will not benefit from an area-based measurement.