Guide
What changed for Class Q on 21 May 2024
Updated
Half the Class Q advice online still describes the pre-2024 rules. Here is the before and after, taken from the two versions of the same provision.
Question 1
Where is the building?
Class Q is a permitted development right in England only. Wales, Scotland and Northern Ireland have separate regimes.
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The substitution
Class Q was substituted in full, not amended, with effect from 21 May 2024 by the Town and Country Planning (General Permitted Development etc.) (England) (Amendment) Order 2024, S.I. 2024/579, article 3 (legislation.gov.uk). That is why old guidance reads so differently: it is describing a provision that no longer exists in that form.
Before and after
| Point | Until 20 May 2024 | From 21 May 2024 |
|---|---|---|
| Number of homes per unit | Maximum 5 | Maximum 10 |
| Size of homes | Up to 3 larger homes within 465 sq m cumulative, plus up to 5 smaller homes of 100 sq m each | One size class: each home up to 150 sq m |
| Cumulative floor space | 465 sq m for larger dwellinghouses | 1,000 sq m across the unit |
| Agricultural use date test | Sole agricultural use as part of a unit on 20 March 2013 | Part of the unit on 24 July 2023, or 10 years |
| Extensions | None permitted | One single storey rear extension, up to 4m deep, on existing hard surface |
| Natural light | A prior approval matter | A prior approval matter the authority must refuse on if not met |
The pre-2024 wording is a point in time version on legislation.gov.uk, so the left column above is quoted, not remembered (version as at 20 May 2024).
What got harder, not easier
- The date test moved forward a decade. A building that qualified on the 20 March 2013 test does not automatically qualify on the 24 July 2023 test.
- Non-agricultural use since leaving the unit is now an express bar, which catches barns let for storage or workshops.
- The nationally described space standard applies, so the building must be capable of complying with it (gov.uk).
- Suitable existing access to a public highway is a hard condition, not a matter for negotiation at prior approval.
What got easier
More homes and a larger cumulative envelope. One generous 150 square metre limit replaced the awkward larger and smaller dwellinghouse split, and a modest rear extension arrived. For a unit with several redundant buildings, capacity roughly doubled.
If a consultant, agent or article quotes 465 square metres, 100 square metre smaller dwellings or five homes, it is out of date. Check the date on anything you rely on.