Garage conversions

Have you got a garage that's full of bikes, a chest freezer and about nine years of things you meant to take to the tip, and you've started wondering whether it could be a room instead?

It's one of the best value projects going and we'd encourage most people to at least look into it. The walls are already up, the roof's already on, the foundations are in the ground, and you're adding proper heated living space without extending the footprint of the house by a single brick or losing any garden. We've turned garages into offices, playrooms, bedrooms, utility rooms, gyms, a very good home cinema and one rather nice snug with a log burner in it.

But a garage was built to keep a car dry, not to keep people warm, and that gap between the two is where all the work lives. There's more on the sort of conversions we design over on the conversions we've worked on.

Usually not, if it's an integral or attached garage and you aren't making the building any bigger. Converting the inside and filling in the garage door opening is normally covered by Permitted Development, because from the council's point of view the building is the same size and shape it always was and only the use of the space inside has changed.

Usually, though. Not always, and the exceptions catch people out.

If you're in a Conservation Area, check. If there's an Article 4 Direction on your street, check, and bear in mind there's nothing on your house to tell you one exists. If you live in a flat you have no Permitted Development rights whatsoever and you'll need a full application.

And then there's the one that catches most people on any estate built since about 1990. A great many modern housing developments were granted planning permission with a condition attached requiring the garage to be kept available for parking a car, and that condition binds you now even though it was agreed between the council and a developer years before you moved in. Converting the garage breaches it. We come across this regularly, the only way to know is to look up the original permission for the house on the council's online register, and most people have never thought to. (We check this as standard, so please just ask.)

A detached garage is a different question again, because you're changing the use of a separate building rather than altering your house, and that far more often needs an application.

Yes. Always, without exception. There is no version of a garage conversion that doesn't need Building Regulations approval, because the whole point of what you're doing is turning a space that wasn't fit for people to live in into one that is, and that's precisely the territory Building Regulations exist to cover.

That's the approval that actually governs the work, and it's the one that produces the completion certificate you'll be asked for when you sell.

Go and stand in your garage for ten minutes and have a proper look at a few things, because the answers will tell you a lot about what you're taking on.

Damp is the first one. Look at the walls, particularly low down, for staining, salting or crumbling plaster. Garages very often have no damp proof course in the walls at all and no damp proof membrane under the floor slab, because neither of those matters much to a car, and both may need dealing with before you can line anything out.

The floor slab is the next thing and it's usually worse than people hope. Garage floors tend to be a fairly thin slab laid straight onto hardcore with no insulation and no membrane underneath, and they're often deliberately laid to fall towards the door so that rainwater and melted snow run out rather than pooling round the tyres. Which means your finished floor isn't level, and sometimes you can build up over the top and sometimes the slab has to come out altogether.

Contamination is worth a sniff. If a car lived in there for thirty years there may well be petrol or oil soaked into the slab, and it smells, and it comes through finishes eventually. Better to know now than after the carpet's down.

Have a look for cracks and movement, especially around the junction between the garage and the house. Garages were often built on shallower foundations than the house they're attached to, because they were only ever carrying a lightweight roof, and differential movement between the two is common. It needs looking at properly rather than filling.

Then the walls themselves. A lot of attached garages are single skin brickwork rather than a proper cavity wall, and single skin won't get anywhere near current insulation requirements and won't reliably keep the weather out either. So you're looking at either building a new inner leaf or insulating internally, and both of those eat into the floor area you were hoping to gain.

And measure the head height before you plan anything at all, because it can disappear faster than you'd think once you've built the floor up over that sloping slab and insulated the ceiling.

This bit gets bodged more often than any other part of the project, and the results show up within a couple of years.

The new wall needs a foundation underneath it. You cannot simply build off the existing slab, because that slab was designed to support a car sitting on it and not a masonry wall pressing down in a line, so that means digging out and putting in a proper footing before you lay a single brick.

If you're putting a window into the new wall then that needs a lintel over it, sized correctly. And whatever you build has to tie in properly to the existing brickwork on either side rather than just butting up against it, or you'll get a straight vertical crack running up the joint within two or three winters, which is both ugly and a route for water.

Getting the new brickwork to match the existing house is the other headache, particularly on older properties where the bricks simply aren't made any more. Sometimes the honest answer is to accept that it won't match and render the whole elevation, or to build the new panel back slightly so the change reads as a deliberate design decision rather than as an obvious patch where a garage door used to be. We'd rather have that conversation with you at the drawing stage than have you look at it every day for twenty years.

Your garage probably has a strip light and a single socket, and that's it.

A habitable room needs proper power, decent lighting, heating and ventilation, and all of it has to meet current standards. If you're extending the central heating into the new room then that's another radiator on a system that was sized without it, so it's worth checking the boiler can actually cope rather than discovering in January that it can't. Any electrical work needs doing by a competent person and certificating under Part P.

Ask yourself this at the beginning rather than at the end.

Losing off street parking affects what your house is worth, and on some streets it affects whether you can park anywhere at all. Estate agents will tell you a garage conversion adds value and generally it does, but not if it leaves a four bedroom family house with nowhere to put two cars.

If there's a driveway in front of the garage you're almost certainly fine, because the parking was never really in the garage anyway. If the garage was the parking, think about it hard before you commit.

Nearly always, if the garage isn't actually being used as a garage. You're getting a proper heated room for a fraction of what an extension would cost, with no loss of garden and no need to touch the roof.

The projects that go wrong are the ones where somebody skipped the Building Regulations entirely, filled the door opening in off the existing slab with no foundation under it, and put a radiator on a single skin wall. Six years later there's damp tracking up the new brickwork, a crack up the joint, no insulation worth the name, and no completion certificate at all when they try to sell.

Get it surveyed, drawn and approved properly and it's one of the best things you can do to a house.

We come and survey the garage, tell you honestly what you're dealing with, and produce the Building Regulation drawings your builder works from. If it turns out you do need planning permission we'll handle that as well.

For more information please call us on 07773 899 597 or contact us through this website.