Class Q permitted development cost
Class Q lets a qualifying agricultural building become a dwelling without a full planning application. Statutory prior-approval fee is £120 per dwelling. A specialist consultant plus drawings typically lands at £6,250 to £12,000 for a single-unit submission.
What Class Q is
Class Q is a permitted-development right in Schedule 2, Part 3 of the GPDO that allows the change of use of an agricultural building to a dwelling, subject to prior approval. Since the 21 May 2025 amendment a qualifying building must have been in agricultural use on 24 July 2023.
The 2025 caps
- Maximum 150 m² gross internal area per dwelling.
- Maximum 10 dwellings on any one established agricultural unit.
- Maximum 1,000 m² of total floor space across the planning unit.
- Curtilage permitted up to 1.0 times the existing building footprint.
What the prior-approval council reviews
Highway impact, noise contour, contamination, flooding, design and external appearance, natural light to habitable rooms, and the building's structural ability to convert without rebuilding. A Class Q application is not a Building Regulations submission and does not test landscape or amenity in the way a full planning application does.
Typical Class Q cost stack
The 56-day clock
From valid receipt the LPA has 56 days to issue prior approval or refusal. Silence at day 57 is a default approval. Many LPAs request additional information mid-process, which suspends the clock; in practice a clean Class Q closes in 6 to 10 weeks.