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.
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 preserved as a point in time version on legislation.gov.uk, which is how the left hand column above can be quoted rather than 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, a larger cumulative envelope, a single and generous 150 square metre size limit instead of the awkward larger and smaller dwellinghouse split, and for the first time a modest rear extension. For a unit with several redundant buildings, the practical 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If a consultant, agent or article quotes 465 square metres, 100 square metre smaller dwellings or five homes, it is out of date.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.