Do you need planning permission for a garden office?
Usually not. A garden office in your own back garden is normally permitted development under Class E, which means it is lawful without anyone approving it. The catch is that "normally" is doing a lot of work, and the rules that decide it are specific.
The short answer
If your garden office is single storey, sits behind the front wall of your house, is no more than 2.5 m tall where it is close to a boundary, and covers a reasonable share of the garden, you almost certainly do not need planning permission. It is permitted development under Class E of the General Permitted Development Order.
That is a statement about the law, not a decision anyone has made about your building. Nobody has checked it. Nobody has written it down. There is no document.
For most people that is fine, right up until it isn't. It stops being fine when you sell the house, when a buyer's solicitor asks what the building in the garden is, when a lender wants proof, or when a neighbour complains and the council writes to you. At that point "it was permitted development" is a thing you believe rather than a thing you can show.
A Lawful Development Certificate is the council writing it down. You apply, they check the facts against Class E, and if it qualifies they issue a certificate confirming the building is lawful. It is not permission. It is proof you never needed permission.
Does your garden office qualify? Ten things that decide it
These are the Class E conditions that matter for a garden building. Get any one of them wrong and the building is not permitted development, whatever the supplier told you.
- It is in your garden, not beyond it. Class E only applies within the curtilage of your house. A building on an adjoining paddock or a separate parcel of land is outside Class E even if you own it and it is next door. This is a question of how the land is actually laid out and used, not of what the deeds say.
- It is single storey. No mezzanine floor, no room in the roof.
- It is behind the front of the house. No part of it can be forward of the wall forming the principal elevation, which for most houses means the front wall facing the road. A front garden studio is not permitted development.
- Its eaves are 2.5 m or lower. This one has no exceptions and it catches people out, because a flat roof design can push the eaves higher than expected.
- It is under the right height limit for where it sits. The overall height cap is 4 m for a dual pitched roof, 3 m for anything else, and 2.5 m for any building where any part is within 2 m of a boundary. Most garden offices sit near a fence, so 2.5 m is the number that usually applies.
- The buildings in your garden cover less than half of it. The 50% cap counts every building in the curtilage except the original house. Sheds, a detached garage, a summerhouse and the new office all pool together against one limit.
- It has no verandah, balcony or raised platform. A raised platform is anything more than 0.3 m high, so a decked area with a step up to it can breach this.
- It is used for something incidental to the house. An office, a gym, a studio, a hobby room or storage are all fine. The test is whether it serves the house rather than functioning as somewhere separate to live.
- It is not sleeping accommodation. A bedroom takes it outside Class E.
- It has no kitchen and no shower. A WC on its own is generally accepted. Add a kitchenette or a shower room and you are arguing that a building with all the facilities for daily living is still incidental to the house, which is an argument people lose.
The 50% rule catches more people than the height rules
The height limits are easy to measure and easy to comply with. The 50% cap is where people get caught, because it is cumulative and because nobody thinks about the shed.
The rule counts the ground area of every building within the curtilage other than the original house, and compares it with the total area of the curtilage. The original house is excluded. Everything else is not: the old shed at the bottom of the garden, the detached garage, the greenhouse on a base, the summerhouse the previous owner left, and the new office. They are added together.
The word "original" matters as well. It means the house as it stood on 1 July 1948, or as first built if later. If a previous owner added a rear extension, that extension is a building in the curtilage and counts towards the cap even though it is attached to the house.
This is also why Class A and Class E cannot be considered separately. A rear extension and a garden office draw on the same allowance. Build one and you have less room for the other.
What it costs
A garden office is an operation within the curtilage of a house, which puts it in a cheaper statutory fee band than an extension. That is worth knowing, because plenty of services quote one flat council fee whatever you are building.
| Planned, not built yet | Already built | |
|---|---|---|
| Which certificate | Section 192, proposed | Section 191, existing |
| Council fee | £136 | £272 |
| Our fee | £349 | £349 |
| Total | £485 | £621 |
The council fee is set by regulation and is the same at every council in England. We pass it through at cost. If the council refuses, we refund our £349 in full. We cannot refund the council fee, because the council keeps it whether it says yes or no.
For comparison, a planning consultant will usually charge £600 to £1,500 to prepare the same application, and an architect more.
Planned or already built
Both are worth doing and they are different applications.
If you have not built it yet, a Section 192 certificate confirms in advance that the building you are describing would be lawful. It is cheaper, the evidence is simply your own drawings and measurements, and it means you find out before you have spent money on the building rather than after.
If it is already there, a Section 191 certificate confirms the building as it stands is lawful. This is the one most people come to us for, usually because a sale is under way. It costs more and it needs evidence: photographs, invoices, and a statement of truth setting out what was built and when.
For a retrospective case the strongest argument is almost always that the building was permitted development when it went up, not that it has been there long enough for the council to have run out of time to act. The first argument does not depend on dates at all. The second one does, and the time limits changed in April 2024.
The three mistakes we see most
Believing the supplier
Garden office companies say "no planning permission required" because it is true of the product in general. It is not a statement about your garden, your boundary distances, or what else you already have out there. The supplier is not checking your curtilage and is not liable if the council disagrees.
Adding the shower later
A building that was clearly incidental when it was an office stops being obviously incidental when someone fits a shower room and a kitchenette. If you are getting a certificate for an office, get it for the office you actually have, and understand that changing the building later can change its status.
Describing it loosely
The single most common self-inflicted refusal is a vague description. "Outbuilding for home office use" tells a case officer nothing. The application needs exact dimensions, the materials, and what each part of the building is for, room by room. If the description is imprecise the officer cannot certify what you have actually built, so they refuse.
How we handle it
- You answer the questions. About ten minutes. Measurements you can take with a tape measure, what is already in the garden, what the building is used for. We check your postcode against the national planning data for conservation areas, Article 4 directions and listed buildings while you are doing it.
- We tell you if it will not work. If your answers put the building outside Class E we say so on screen, before you pay anything. We would rather lose the sale than take money for an application we expect to fail.
- We draft the application. The statement, the application form and the covering letter, working through the Class E conditions one at a time with your figures against each one. You review all of it before anything is sent.
- We file it and deal with the council. Including any questions the case officer asks during the eight week determination period. You get the certificate.
Questions people actually ask
My garden office is on a concrete base and could be moved. Does it still count as a building?
Almost certainly yes. Whether something is a building for planning purposes depends on its size, its permanence and how attached it is to the ground, not on whether it arrived flat packed. A garden room on a base, connected to power, used year round, is a building.
Does the office need to be under 30 m² or 15 m²?
Those figures come from Building Regulations, not planning. A building under 15 m² generally does not need building regulations approval, and one between 15 m² and 30 m² may not if it contains no sleeping accommodation and meets conditions on its position and construction. None of that has anything to do with whether it is permitted development. Planning and Building Regulations are separate systems and you can comply with one and not the other.
Can I run a business from it?
Working from home in it is fine, and that is what most people mean. It becomes a planning problem if the use stops being incidental to living in the house, for example if staff and customers come and go, or if the building is effectively separate business premises. Ordinary remote work is not that.
What if I am in a conservation area?
Class E is restricted on that kind of land and outbuildings to the side of the house are removed altogether. We do not currently take conservation area cases, or Article 4 areas, or listed buildings. The intake checks all three from your postcode and tells you straight away rather than taking your money first.
Does a certificate expire?
No. It attaches to the building and the facts as they were. It stays valid as long as the building stays as described. If you materially change it, the certificate covers the old building rather than the new one.
How long does it take?
The council has eight weeks to decide. That is a statutory period and we cannot speed it up. What we control is the part before filing, which is usually where the delay actually is: we draft within two working days of payment, and same day on the Express tier.
The honest position
Most garden offices are lawful and their owners will never need to prove it. If you are not selling and nobody has asked, you can reasonably leave it.
The people who should get a certificate are the ones with a transaction in view, the ones whose building sits close to a limit, and the ones who want the question closed permanently rather than reopened by every future buyer. If that is you, the intake will tell you in five minutes whether your building qualifies, and it costs nothing to find out.
Check if your garden office qualifies →Related reading
- What is a Certificate of Lawfulness? The full explanation of what the document is and does.
- Loft conversions and Class B for the 40 m³ and 50 m³ volume rules.
- Rear extensions and Class A which shares the 50% curtilage cap with garden buildings.
- What an LDC costs including the fee bands by project type.
- How LDC Express works from intake to certificate.