Research into the quality standard of homes delivered through change of use permitted development rights

Overview of the Research

The study “Research into the quality standard of homes delivered through change of use permitted development rights” was commissioned by the Ministry of Housing, Communities and Local Government (MHCLG). It was authored by a team of academics and experts – Dr Ben Clifford, Dr Patricia Canelas, Dr Jessica Ferm, Dr Nicola Livingstone (Bartlett School of Planning, UCL), Professor Alex Lord and Dr Richard Dunning (Department of Geography and Planning, University of Liverpool). Published in July 2020, the research investigates the residential quality of homes created by converting commercial buildings to housing under permitted development rights (PDR) across eleven English local authorities.

Scope and Methodology

The project examined 639 building sites (417 prior‑approval cases and 222 full planning permission cases) visited between 2015 and 2018. Detailed desk analysis was performed on 240 schemes, covering 3 156 residential units. Data sources included local authority planning databases, site visits, interviews with 11 planning officers and 12 developers/agents, and GIS analysis of neighbourhood deprivation, green space, transport and service accessibility. The study compared three change‑of‑use categories – office‑to‑residential, retail/sui‑generis‑to‑residential, and storage/light‑industrial‑to‑residential – across Bristol, Crawley, Derby, Enfield, Huntingdonshire, Manchester, Richmond, Sandwell, Sunderland, Wakefield and Waverley.

Key Quantitative Findings

• Total units examined: 3 156 (2 818 from permitted development, 338 from planning permission).
• Office‑to‑residential schemes accounted for 86 % of units; retail for 7 %; storage/light‑industrial for 1 %.
• Only 22 % of units created under permitted development met the Nationally Described Space Standard (NDSS), versus 73 % for planning‑permission units.
• Studios and one‑bedroom flats comprised 69 % of permitted‑development units but only 44 % of planning‑permission units.
• Single‑aspect windows were present in 72 % of permitted‑development units compared with 30 % of planning‑permission units; dual or triple aspect windows occurred in 27 % versus 67 % respectively.
• Private amenity space was available in 3.5 % of permitted‑development units versus 23 % of planning‑permission units.
• Energy Performance Certificate (EPC) ratings clustered around C and D for both routes; no permitted‑development unit achieved grade A.
• Approximately 0.4 % of permitted‑development units had no windows at all.

Geographic and Socio‑Economic Patterns

Compliance with NDSS varied widely by authority, from 3 % in Derby to 67 % in Richmond for permitted‑development units. Higher compliance correlated with lower deprivation scores and higher house prices; more deprived areas (e.g., Sunderland, Sandwell) showed lower compliance. Schemes located in primarily commercial or industrial zones were eight times more common under permitted development (7.9 % of PD schemes) than under planning permission (1.0 %). Office vacancy rates and rental levels also influenced outcomes: higher vacancy and lower rents were linked to smaller average unit sizes and poorer space‑standard performance.

Planning and Policy Insights

• Approval rates were higher for permitted development (83 %) than for planning permission (73 %).
• About one‑third of permitted‑development schemes involved an associated planning permission for external works such as new windows, doors or cladding.
• Local authorities reported limited ability to impose Section 106 contributions on permitted‑development conversions; Community Infrastructure Levy (CIL) was applied in only a minority of cases, often exempted when no new floor‑space was created.
• Interviewees highlighted inconsistent handling of prior approvals, resource pressures, and lack of clear guidance on quality standards as challenges.
• Developers valued the speed and lower costs of permitted development but noted quality variation, especially in low‑demand markets where small studios dominate.

Implications for Sustainable Housing

The research underscores that while permitted development accelerates housing delivery, it frequently results in smaller, less spacious units with limited natural light and amenity provision, potentially affecting occupant well‑being and long‑term sustainability. Higher‑quality outcomes are more common where local planning policies incorporate space‑standard requirements and where market conditions support larger, better‑designed conversions. The findings suggest that aligning permitted‑development practice with sustainable housing standards – such as ensuring adequate floor area, daylight, and communal or private outdoor space – could improve the environmental and social performance of converted homes across Europe.