In most cases you do not need planning permission for a garden room in Southwark.
Most garden offices, studios and garden rooms are built under permitted development, which means
no planning application at all. The exceptions matter though, and in this borough they catch more
people out than you would expect, because Southwark has a lot of conservation areas and a lot of
flats.
Here is how it actually works, and how to check your own address before you commit to a design.
The permitted development rules that decide it
A garden building is normally permitted development if all of the following are true:
- It is single storey, with eaves no higher than 2.5 metres.
- Overall height is no more than 4 metres for a dual-pitched roof, or
3 metres for any other roof shape. - If any part of it sits within two metres of a boundary, the whole thing must
be no more than 2.5 metres tall. In a typical London garden this is the rule that
bites first. - It does not sit forward of the principal elevation of the house, meaning it is
behind the front wall. - Together with any other outbuildings and extensions, it covers no more than half
of the land around the original house. - It has no veranda, balcony or raised platform over 0.3 metres.
- It is incidental to the enjoyment of the house. An office, gym, studio or
workshop is fine. Somewhere to sleep is not.
When you will need planning permission in Southwark
You live in a flat or maisonette
Permitted development rights for outbuildings apply to houses, not to flats or maisonettes. If
your home is a flat, you need planning permission for a garden building regardless of its size.
Given how much of Southwark is converted Victorian terraces split into flats, this catches a lot
of people.
Your property is in a conservation area
Southwark has a large number of conservation areas, including parts of Dulwich, Herne Hill and
Camberwell. In a conservation area two extra restrictions apply. You cannot build to the
side of the house under permitted development, and a building of more than 10 square
metres sited more than 20 metres from the house also loses permitted development
rights.
Your house is listed
A listed building needs listed building consent for work in its curtilage, which includes a
garden building. This is separate from planning permission and you may need both.
An Article 4 direction applies
Councils can remove permitted development rights from specific areas using an Article 4
direction. If one covers your street, the normal rules do not apply. This is worth checking rather
than assuming.
How to check your own address
Do not rely on what a neighbour got away with. Two things to do before you design anything:
- Check Southwark’s planning map for your address, to see whether you are in a
conservation area, whether the building is listed, and whether an Article 4 direction applies.
Southwark’s planning pages are at
southwark.gov.uk. - Consider a Lawful Development Certificate. If the build is permitted
development, you can apply to the council for a certificate confirming it. It is not compulsory,
but it costs far less than a planning application and it is the document a buyer’s solicitor will
ask for when you sell.
For the national picture rather than the Southwark detail, see our guide to planning permission for a garden room. If your address is in a conservation area, read what conservation area status means for a garden building.
Building regulations are a separate question
Planning permission and building regulations are two different systems. You can need one, both
or neither.
- Detached, single storey, under 15 square metres of floor area: generally no
building regulations approval needed. - 15 to 30 square metres: usually still no approval needed, provided there is no
sleeping accommodation and the building is either at least one metre from any boundary or built
substantially from non-combustible materials. - Over 30 square metres: building regulations approval is required.
Electrical work is notifiable under Part P whatever the size, so any garden building with power
run to it needs that side signing off.
How we handle this
We check planning constraints at the site visit, before any design work. If your address is in
a conservation area, or the boundary distance means the 2.5 metre limit applies, we design around
it rather than discovering it halfway through. If an application is genuinely needed, we tell you
before you commit to anything.
You can see what that looks like in practice across our
garden building project gallery, or on the
project map, street by street.
Frequently asked questions
Do I need planning permission for a garden room in Southwark?
Usually not. Most garden rooms are built under permitted development, which means no planning application is needed. You will need permission if the building sits forward of the front of your house, is taller than the limits, covers more than half your garden, or if your property is a flat, is listed, or sits in a conservation area where the rules are tighter.
How tall can a garden room be without planning permission?
Up to 2.5 metres if any part of it is within two metres of a boundary. If it is further than two metres from every boundary, you can go to 3 metres for a flat or mono-pitched roof, or 4 metres for a dual-pitched roof, with eaves no higher than 2.5 metres.
Can I put a garden room in a Dulwich conservation area?
Often yes, but the rules are tighter. In a conservation area you cannot build to the side of the house under permitted development, and a building over 10 square metres sited more than 20 metres from the house also loses permitted development rights. Check your address on Southwark’s planning map before committing to a design.
Do garden rooms need building regulations approval?
A detached single storey garden room under 15 square metres of floor area generally does not need building regulations approval. Between 15 and 30 square metres it usually still does not, provided there is no sleeping accommodation and it is either at least one metre from any boundary or built substantially from non-combustible materials. Over 30 square metres, approval is required. Electrical work is notifiable either way.
Can I sleep in my garden room?
Not under permitted development. Permitted development covers buildings that are incidental to the enjoyment of the house, such as an office, gym or studio. A building intended for sleeping or as self-contained accommodation is a different use and needs planning permission, and building regulations approval.
Thinking about a garden building?
We build garden room builders in South London,
garden office builders in East Dulwich,
garden art and music studios,
garden yoga and exercise studios and
bespoke garden sheds and storage across East Dulwich and South London.
Book a free site visit and we will tell you where you stand on planning
before you spend anything.
This article is general guidance, not planning advice. Permitted development rules change
and every address is different. Always confirm your own situation with Southwark Council or a
planning consultant before you build.