If you need more space and you have the garden for it, a garden room gets you there in
weeks rather than months, usually without a planning application and without moving out.
An extension adds floor area to the house itself and usually adds more to its value. They solve
different problems.
The honest comparison
Time
A garden room is typically a matter of weeks on site. A rear extension is months, plus the
planning and building control process before anyone starts.
Disruption
This is the big one. An extension means opening up the back of your house, dust through every
room, and often no kitchen for a stretch. A garden room is built at the end of the garden. You
carry on living normally.
Planning
Most garden rooms are permitted development. Many extensions are too, but the moment you go
beyond the permitted limits you are into an application, and in a conservation area the bar is
higher again.
Value
An extension adds internal floor area, which is what valuers measure, so it generally adds more.
A well built garden room still adds value, and it costs considerably less to get there.
What you actually get
An extension usually makes an existing room bigger. A garden room gives you a separate space
with a door you can close, which is the whole point if you are working from home or need somewhere
quiet.
When an extension is the better answer
- You need more bedrooms. A garden room cannot be sleeping accommodation under
permitted development. - You need a bigger kitchen or living space connected to the rest of the house.
- Your garden is too small to lose any of it.
- You are optimising purely for resale value per pound spent.
When a garden room is the better answer
- You need a separate room to work, train or make things in.
- You cannot face the disruption of building work through the house.
- You want it this year, not next.
- Your garden is long enough that losing the far end costs you nothing you use.
Most of the garden office builders in East Dulwich we build are for exactly this reason. People wanted an extra room and
did not want to lose a bedroom, move house, or live through six months of building work.
Frequently asked questions
Is a garden room cheaper than an extension?
Generally yes, and by a significant margin, because there are no structural alterations to the house, no making good inside, and a much shorter build programme.
Does a garden room add value to a house?
A well built, insulated garden room with power does add value, though an extension typically adds more because valuers measure internal floor area. The gap narrows once you account for the difference in cost.
Can a garden room replace a bedroom?
Not under permitted development. A building used for sleeping is a different use and needs planning permission and building regulations approval.
Which is quicker, a garden room or an extension?
A garden room, by a wide margin. Weeks on site rather than months, and usually no planning application to wait for.
Thinking about a garden building?
We design and build bespoke garden rooms and studios, purpose built garden offices, garden art and music studios, garden yoga and exercise studios and bespoke garden sheds and storage across East Dulwich, Dulwich, Peckham and the surrounding South London areas. See our garden building project gallery or the project map of every build, then book a free site visit and we will give you an honest estimate with no obligation.