Not every Blackburn house has one
Walk down most streets near the town centre and you won't see a garage door. Terraced houses make up over 46% of the borough's homes, according to the council's housing strategy, and the classic mill worker's house was built with a yard behind it opening onto a back street. The car lives on the road. There's nothing to convert.
So the work here is mostly on other kinds of house. Semis are about a quarter of the stock and detached homes 11%. Think of the interwar semis at Green Lane, the private houses that went up along Buncer Lane and Pleckgate, and the newer estates the council's strategy pictures at Gib Lane, Roman Road, Whalley Old Road and Sunnybower. That's where a spare garage full of bikes and boxes tends to be.
Count the bedrooms before you count the cars
Turning a garage into a room normally needs no planning application, says the Planning Portal, as long as the work is inside and the building isn't made any bigger. Where an application is needed, Blackburn with Darwen looks at parking under Local Plan policy DM29. Its committee reports have quoted the BwD Parking Standards (2014), which ask for two car spaces for a house with two or three bedrooms and three spaces for four bedrooms or more.
Do the sum for your own house. A three bed that gains a ground floor bedroom becomes a four bed, and the standard goes up by a space just as the garage space disappears. If the drive takes two cars end to end, say so on the drawings. If it takes one, expect the question.
On a newer estate, read the original decision notice first. The Planning Portal warns that some houses, particularly on new developments, have had their permitted development rights for garage conversions taken away. Any such condition is listed at the end of the notice, and a lawful development certificate settles it if the wording is unclear.
Choosing what to turn it into
Roughly in the order they come up on Blackburn's semis and estate houses. Each links to a longer guide.
Integral garage. Built into the house. Check the decision notice before anything else, because this is the type where a removed right is most likely to bite.
Single garage. Beside a semi it gives one room, and the new wall where the door was will probably need its own footing.
Read our full guide: Single Garage Conversion: What Is Involved and What to Budget For →
Bedroom. Useful for a relative who can't manage the stairs. Just remember it adds to the bedroom count the parking standard is based on.
Home office. No extra bedroom, so the parking sum doesn't change. A good choice on a three bed where the drive is tight.
Utility or playroom. Moving the washing machine out of a small kitchen and into the old garage frees more room than you'd expect, and there's no new bedroom to count.
Double garage. Found on some detached houses. Converting one bay and keeping the other for a car is the easiest way to answer a parking objection.
Detached garage. Used as a workshop, gym or office for the household, it stays part of the house. Someone living in it as a separate home is another matter, and the Planning Portal says that may need permission whatever building work is done.
Gym or studio. Where your garage backs onto next door's, put sound insulation in the budget before the rubber flooring.
Planning and building control. Planning depends on your house's permission history and where it sits. Building Regulations approval is needed almost every time the garage becomes a room people use.
Cost and value. No prices here. The footing under the old door, the state of the slab and whether you need to make room for another car on the drive are what split the quotes.
Footings, floors and the ground underneath
The Planning Portal expects the old door opening to be filled with a new wall, perhaps with a window, and says a new foundation may be needed for it. The floor, walls and ventilation all have to come up to the standard of a room someone lives in. Here the inspection is done by Pennine Lancashire Building Control, which the council runs with Burnley, unless your builder uses a private inspector.
A footing is digging, however short. Blackburn has old coal workings in more places than people expect, so check the Mining Remediation Authority's map before the trench goes in.
Radon is less of a worry here than in some parts of the country. When the government's radon survey reported in 2016, none of the 30 homes tested in Blackburn with Darwen reached the action level. That's a small sample, so still look your postcode up on the UKradon map.
One more check if you're near the River Darwen around Ewood or the Blakewater between Cob Wall and the town centre. A bedroom on the ground floor is the room you least want water in, so look at the flood map before choosing it over an office or utility. In a conservation area, ask the council before swapping a garage door for a wall and window.
Where these facts come from
- Blackburn with Darwen Council: committee report citing DM29 and the Residential Design Guide
- Blackburn with Darwen Housing Strategy 2026-2036
- Cotton Town: terraced and modern housing
- Cotton Town: housing between the wars
- Planning Portal: garage conversion planning permission
- Planning Portal: building regulations for garage conversions
- UKHSA: radon in homes in England, 2016 data report
- Mining Remediation Authority: home improvements in former coal mining areas
- Cotton Town: coal mining in the area
- Environment Agency: River Darwen at Ewood flood warning area
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Questions people in Blackburn ask
We live on one of the newer estates. How do we find out if the garage has to stay a garage?
Look up the permission for the estate on the council's planning register and read the conditions at the end of the decision notice. If one removes permitted development rights or says the garage must be kept for parking, you'll need to apply. If the wording is unclear, a lawful development certificate gives you a firm answer.
Our three bed semi only has room on the drive for one car. Will converting the garage be refused?
If no application is needed, parking isn't tested. If one is, the council's 2014 parking standards ask for two spaces on a two or three bed house and three on a four bed, so a bedroom conversion with one space on the drive is the hardest case. An office or playroom keeps the bedroom count the same.
Do I need to worry about radon in a converted garage in Blackburn?
The national survey found low readings across the borough, with none of the homes tested reaching the action level. It's still worth a postcode check on UKradon before the new floor goes down.