Do you need planning permission for an outbuilding in London?
Often not. A garden outbuilding is permitted development if it stays within the Class E limits, which include 2.5 metres high within 2 metres of a boundary, otherwise 3 metres, or 4 m with a dual-pitched roof, and no more than half the garden covered. Break any limit and you need to apply.
Prefer to talk it through?
The height limits in Class E
Outbuildings for incidental use, such as a shed, a summerhouse or a garden office, are covered by Class E of Part 1 in Schedule 2 to the General Permitted Development Order 2015 (legislation.gov.uk). The height rules depend on where the building stands.
Within 2 metres of the boundary of the garden, the building may be up to 2.5 metres high. Elsewhere, the limit is 3 metres in any other case, rising to 4 m where the roof is dual-pitched. So a pitched-roof studio set in the middle of the garden can be taller than one tucked against the fence.
How much of the garden you can cover
Class E.1(b) limits the total ground covered by buildings, enclosures, pools and containers in the curtilage, other than the original house, to 50% of the curtilage. Count everything else already in the garden before you add the new building, including earlier extensions and existing sheds.
Class E also restricts raised platforms, and a platform counts as raised when it is higher than 0.3 metres, so a raised deck or base can take a building outside the right.
Our garden room permitted development drawings start at £495; see the garden room drawings page.
When you do need to apply
You apply if the design breaks any of these limits, if it would stand forward of the front wall of the house, if it has more than one storey or exceeds the Class E eaves limit, if the building would be used as living accommodation, or if the right has been withdrawn or restricted on your property. In a conservation area or on other designated land, additional restrictions can apply, so ask the council before you order a building.
If you apply, an application for operations within the curtilage of a house for ancillary purposes such as an outbuilding carries a fee of £272 from 1 April 2026 (category 7 of SI 2012/2920 as indexed, per the government fee table). Our garden room planning guide covers the case of a room used as an office or studio.
Building Regulations are a separate test
Permitted development under planning does not answer the Building Regulations question. Schedule 2 of the Building Regulations 2010 exempts a detached building with a floor area not exceeding 15m2 and no sleeping accommodation. A detached single-storey building up to 30m2 with no sleeping accommodation is also exempt if it is at least one metre from the boundary or built substantially of non-combustible material.
Over those sizes, or if someone will sleep in it, building control will be involved. Our guide on Building Regulations approval explains when approval is needed and who gives it.
Get the drawings right before you build
Whether you rely on permitted development or apply, a drawing that shows the footprint, the heights and the distance to each boundary is what proves the building is within the limits. If you want certainty, a lawful development certificate puts the council's confirmation on record.
Our garden room permitted development drawings start at £495; see the garden room drawings page. For the wider picture, our lawful development certificate guide explains the certificate.
Sources
Every figure on this page, where it comes from and a link to the original.
| Figure | Source | Link |
|---|---|---|
| 2.5 metres | GPDO 2015 Sch 2 Pt 1 Class E.1(e)(ii): an outbuilding within 2 metres of the curtilage boundary may be up to 2.5 metres high (source wording: "2.5 metres in the case of a building ... within 2 metres of the boundary") | www.legislation.gov.uk |
| 3 metres | GPDO 2015 Sch 2 Pt 1 Class E.1(e)(iii): in any other case an outbuilding may be up to 3 metres high (source wording: "3 metres in any other case") | www.legislation.gov.uk |
| 4 | GPDO 2015 Sch 2 Pt 1 Class E para E.1(e)(i): max height of building with dual-pitched roof (source wording: 4 metres) | www.legislation.gov.uk |
| 50% | GPDO 2015 Sch 2 Pt 1 Class E para E.1(b): total ground cover of buildings, enclosures, pools and containers must not exceed 50% of curtilage | www.legislation.gov.uk |
| 0.3 | GPDO 2015 Sch 2 Pt 1 Class E.1(h) and para I: raised platform means a platform with a height greater than 0.3 metres (source wording: 0.3 metres) | www.legislation.gov.uk |
| 15m2 | Building Regulations 2010 Sch 2 Class 6 para 3: a detached building with a floor area not exceeding 15m2 and no sleeping accommodation is exempt (source wording: "not exceed 15m2") | www.legislation.gov.uk |
| 30m2 | Building Regulations 2010 Sch 2 Class 6 para 1: a detached single-storey building not exceeding 30m2, with no sleeping accommodation and at least one metre from the boundary or built substantially of non-combustible material, is exempt (source wording: "not exceed 30m2") | www.legislation.gov.uk |
| £272 | Fees for planning applications in England from 1 April 2026 (MHCLG, SI 2012/2920 as annually indexed), category 7: operations within the curtilage of a house for purposes ancillary to its enjoyment, such as an outbuilding, or gates, fences and walls on its boundary (source wording: £272) | assets.publishing.service.gov.uk |
| £495 | DrawingsDirect starting fixed fee for garden room permitted development drawings, from the published price list | drawingsdirect.co.uk |