England only. GPDO 2015, as amended 21 May 2024
Can you do a Class Q barn conversion?
Class Q turns English farm buildings into homes via prior approval, not planning permission. Since 21 May 2024: up to 10 a unit, 150 m² each, 1,000 m² total, use tested at 24 July 2023. Designations or rebuilds bar it.
150 m²
maximum floor space of any single dwellinghouse developed under Class Q
10 homes
cumulative maximum per established agricultural unit, and 1,000 m² of floor space
56 days
for the council to determine prior approval before you may begin
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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Class Q conditions and limits, current text
Last updated
Every numerical limit and hard condition in Class Q as it stands today, after the 21 May 2024 substitution. If a source quotes 5 dwellings, 465 square metres or 100 square metre smaller dwellings, it is describing the old version.
| Condition | The limit | Provision |
|---|---|---|
| Size of each new home | Floor space of any dwellinghouse must not exceed 150 square metres | Q.1(c) |
| Number of homes per agricultural unit | Cumulative total under Class Q must not exceed 10 dwellinghouses | Q.1(d)(i) |
| Total floor space per agricultural unit | Cumulative floor space must not exceed 1,000 square metres | Q.1(d)(ii) |
| Agricultural use date test | Site must have been part of the established agricultural unit on 24 July 2023, or for at least 10 years before development begins | Q.1(a) and (b) |
| Use since leaving the unit | No use for any non-agricultural purpose since the site ceased to be part of the unit | Q.1(b)(iii) |
| Agricultural tenancy | Not permitted where the site is occupied under an agricultural tenancy, unless landlord and tenant both expressly consent | Q.1(e) and (f) |
| New farm buildings under Part 6 | Blocked where Part 6 Class A(a) or B(a) development was carried out on the unit in the previous 10 years | Q.1(g) |
| Footprint | No extension beyond the existing external dimensions, other than the permitted rear extension and protrusions of up to 0.2 metres | Q.1(h) |
| The rear extension | Single storey, to the rear only, no more than 4 metres beyond the rear wall, eaves no higher than existing, no higher than the lower of the existing roof or 4 metres, on hard surface in place since 24 July 2023 or for 10 years | Q.1(i) |
| Permitted building operations | Installing or replacing windows, doors, roofs, exterior walls and services, plus partial demolition reasonably necessary to do so | Q.1(j) |
| Designations | Not permitted on article 2(3) land, SSSIs, safety hazard areas, military explosives storage areas, scheduled monuments or listed buildings | Q.1(k) to (n) |
| Space standard and access | Must be capable of complying with the nationally described space standard, and have suitable existing access to a public highway | Q.1(o) and (p) |
| Prior approval | Application required before beginning; development may proceed if not determined within 56 days | Q.2 and W(11) |
| Completion | Development must be completed within 3 years of the prior approval date | Q.2(4) |
- Under the current Class Q, a single dwellinghouse created from an agricultural building in England must not exceed 150 square metres of floor space, and no more than 10 homes totalling 1,000 square metres may be created within one established agricultural unit.
- Class Q is blocked entirely where the building is listed, is or contains a scheduled monument, or the site is on article 2(3) land, which includes National Parks, areas of outstanding natural beauty, conservation areas, the Broads and World Heritage Sites.
- Class Q development may begin if the local planning authority has not notified the applicant whether prior approval is given or refused within 56 days of receiving the application, and must be completed within 3 years of the prior approval date.
How this was compiled, and how to cite it
Taken from the current consolidated text of Class Q of Part 3 of Schedule 2 to the Town and Country Planning (General Permitted Development) (England) Order 2015 on legislation.gov.uk, checked on the updated date above. Class Q was substituted 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. Paragraph references are to Class Q itself and to paragraph W of Part 3, which governs the prior approval procedure. No planning application fee is quoted here because fees are set by separate regulations and change: confirm the current figure with your local planning authority.
Cite this page
“Class Q conditions and limits, current text”, Class Q Checker, https://classqchecker.co.uk/ (updated 2026-08-14). Taken from the current consolidated text of Class Q of Part 3 of Schedule 2 to the Town and Country Planning (General Permitted Development) (England) Order 2015 on legislation.gov.uk, checked on the updated date above. Class Q was substituted 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. Paragraph references are to Class Q itself and to paragraph W of Part 3, which governs the prior approval procedure. No planning application fee is quoted here because fees are set by separate regulations and change: confirm the current figure with your local planning authority.
What it does and does not check
The 7 things it checks
- England only: Class Q of Part 3 of Schedule 2 to the GPDO 2015, as substituted on 21 May 2024
- The agricultural use test tied to 24 July 2023, and the ten year alternative
- Designations that block Class Q outright: listed buildings, scheduled monuments and article 2(3) land
- The size limits: 150 square metres per home, 10 homes and 1,000 square metres per unit
- What building operations are allowed, and the single storey rear extension added in 2024
- The prior approval process, its seven matters and the 56 day determination period
- Not covered: agricultural tenancy consents and Part 6 interactions are flagged but need a professional check
Class Q Checker is an information site. It is not affiliated with any local planning authority, the Planning Inspectorate or any government department, and nothing here is planning or legal advice. It covers England only, and it cannot see your site: designations, use history and structural condition all have to be confirmed locally before you rely on a Class Q route.
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Common questions
What is Class Q permitted development under the GPDO?
Class Q of Part 3 of Schedule 2 to the Town and Country Planning (General Permitted Development) (England) Order 2015 covers agricultural buildings. It lets one on an established unit, or a former one, become a dwellinghouse. Necessary building operations are allowed, subject to conditions and the local planning authority's prior approval. England only.
Where is the Class Q legislation?
Class Q is in Part 3 of Schedule 2 to the Town and Country Planning (General Permitted Development) (England) Order 2015, S.I. 2015/596 (legislation.gov.uk). S.I. 2024/579 substituted it from 21 May 2024. Q.1 sets what is not permitted, Q.2 conditions and prior approval, Q.3 interpretation, including curtilage.
Does Class Q apply to my barn if it is in a conservation area?
No. Class Q is not permitted where the site is on article 2(3) land, which includes conservation areas, National Parks, areas of outstanding natural beauty, the Broads and World Heritage Sites. It is also blocked for listed buildings, scheduled monuments, sites of special scientific interest, safety hazard areas and military explosives storage areas.
What is the 24 July 2023 date in Class Q?
It is the anchor for the agricultural use test in the current rules. The site must have been part of an established agricultural unit on 24 July 2023. Where it joined the unit later, or ceased to be part of it later, a period of at least 10 years before development begins applies instead.
Do I need planning permission for a Class Q conversion?
Not a full planning application. You must ask the local planning authority to determine whether prior approval is required, and cannot begin until it decides or 56 days pass. Building regulations approval is separate, and not covered by Class Q.
Can a barn used for storage be converted under Class Q?
Usually not. Class Q is not permitted where, since ceasing to be part of an established agricultural unit, the site has been used for any non-agricultural purpose. Commercial storage, workshops, liveries and holiday letting all count against the building's eligibility.
How long do I have to finish a Class Q conversion?
Three years. Class Q.2(4) requires the change of use, and any extension or building operations, to be completed within a period of 3 years starting with the prior approval date.
Worth knowing
The longer answers, with sources.
What changed for Class Q on 21 May 2024
Class Q was substituted on 21 May 2024: 10 homes instead of 5, 150 sq m each instead of two size classes, a new date test and a permitted rear extension.
Class Q application and prior approval: seven matters, 56 days
Class Q is conditional on applying to the council for prior approval. What you must submit, what the council can assess, and when you can lawfully start.
Class Q size limits: 150 sq m per home, 10 homes, 1,000 sq m
How the Class Q floor space limits work, how previous conversions on the same unit count, and exactly what the permitted rear extension may and may not do.
Class Q refused or ruled out: what your options actually are
Appeal, resubmit or apply for full planning permission. What each route is for when a Class Q barn conversion is refused or blocked by a condition.
Sources
This site's own datasets, every figure quoted from its source and dated:
- The Barn Conversion Cost Index carries 14 published figures read from 9 sources' own pages; the 6 published figures given without a breakdown run from 1,200 to 2,500 GBP, read 11 November 2026.
- The Class Q Statutory Tests carries 5 published figures read from 1 source's own page, from 3 to 10 year, read 7 November 2026.
- Class Q, GPDO 2015 Schedule 2 Part 3, current text
- GPDO 2015 Schedule 2 Part 3, including paragraph W (prior approval)
- GPDO 2015 Schedule 1, article 2(3) land
- Amendment Order 2024, S.I. 2024/579, which substituted Class Q
- gov.uk, technical housing standards: nationally described space standard
- gov.uk, when is permission required
- gov.uk, find your local council
Check it before you draw it
Eight questions against the current Class Q text. Most schemes fail on history or designations, not design.
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