The lowest floor in a low town
A garage slab is usually the lowest floor a house has. In most places that's a detail. In Boston, built on drained fen with much of the land below sea level, it is the first thing we'd look at.
The Planning Portal's own building regulations notes say the old garage floor will usually need a new damp proof membrane and insulation, and that you may want to lift it to match the rest of the house. Here we'd treat that as the starting point rather than an option. A floor level with the hall is warmer and a little further from any water.
Think hard about who sleeps in the room. The local plan's flood policy is written for changes of use, not for a family converting its own garage, but its logic is sound. In the town's higher hazard areas it won't support self-contained ground floor homes, and it wants people to have unrestricted access to a habitable room above the flood level. In a two storey semi that's the stairs. In a bungalow there is no upstairs, so a garage bedroom for an older relative deserves a frank talk with your designer first.
Where Boston's garages are
Lincolnshire County Council's survey of the town never mentions garages, but it does say where the driveways are, and that's a fair guide. The planned semis and bungalows north of the centre sit on plots with a garden and often a drive, with cul-de-sacs becoming more usual from the late twentieth century. The 1950 to 1975 estates out east wind along long cul-de-sacs, many with a drive in front. West of the centre, on the newer streets, some of the parking is behind the houses.
The railway terraces around Tower Street and James Street are the other extreme. The survey says no parking was provided at all, so garages there are rare.
Choosing the right kind of conversion
Integral. Typical of the later estates north and east of the centre. The Planning Portal warns that rights to convert are sometimes removed on newer developments, so ask the council for your estate's original decision notice before paying for drawings.
Home office. Our first suggestion on a bungalow, where the garage is the only room you can add without building out. A desk copes with a low floor far better than a bed does.
Single. A new wall fills the door opening, and the Portal notes it may need its own foundation. On drained fen, building control will want to see what the existing footing sits on before agreeing a design.
Read our full guide: Single Garage Conversion: What Is Involved and What to Budget For →
Utility or playroom. A utility is the low-risk way to use a garage floor that can't easily be raised. A playroom is living space, so it goes through building control like any other room.
Bedroom. Fine in a house with an upstairs to retreat to, once building control is happy with the window and ventilation. Read the flood section above before planning one in a bungalow.
Double. Found on the bigger detached houses. Keeping one bay for the car and converting the other is often the tidiest answer.
Detached. Used by the household as a gym or study, it stays part of the home. Turn it into a separate house, whoever lives there, and the Portal says permission may be needed whatever the works. In Boston's higher hazard flood areas the local plan won't back new self-contained ground floor homes through a change of use.
Gym or studio. A concrete floor suits weights. Line the walls if the garage joins next door's.
Planning and approval. Internal work that doesn't enlarge the house usually needs no planning application. Building regulations approval is a separate step, and the council treats a garage turned into habitable rooms as its own category of job.
Cost. We don't print Boston prices. Lifting the floor and putting a new footing under the infill wall are what move a local quote most.
Central Park, Article 4 and the front of the house
One corner of Boston has had tighter rules since 26 September 1988. An Article 4 direction around Central Park covers parts of Thorold Street, Norfolk Street and Tawney Street. There, changing any wall that faces a public highway needs planning permission, and the direction names windows, window openings, doors and facing brickwork. Bricking up a street-facing garage door and fitting a window is exactly that kind of change. Laying a hardstanding for a drive in front of the house is caught too.
The council's appraisal of the town centre conservation area recommends extending Article 4 controls to more streets, including Tunnard Street, Witham Bank and Haven Bank. Ask the council whether your street has been added before you order a window. The appraisal also complains about plastic replacing original timber, so match the house rather than the catalogue.
Moving the car onto the drive
Lincolnshire County Council, not the borough, deals with dropped kerbs. It builds only the part on the highway, and only in tarmac, or you can have a contractor do it. If the new access affects a ditch or watercourse, the county wants the drainage board's consent first.
Building control is Boston Borough Council's own team at Municipal Buildings. A full plans application gets the drawings checked before the builder starts.
Where these facts come from
- South East Lincolnshire Local Plan 2011 to 2036 (adopted 2019)
- Boston Borough Council: Boston Conservation Area Appraisal and Management Plan
- Lincolnshire County Council: Boston Extensive Urban Survey
- Lincolnshire County Council: apply for a dropped kerb or vehicle access
- Boston Borough Council: building control forms and charges
- Boston Borough Council: building control overview
- Planning Portal: garage conversion
- Planning Portal: garage conversion building regulations
- Planning Portal: garage conversion flooring
- Planning Portal: in-filling the garage door
How FirQuote works in Boston: We connect you with local specialists who visit your property before giving you a price. You get up to 3 written quotes — no call centres, no estimates from photos, no obligation to accept any quote.
Questions people in Boston ask
Our house is near Central Park. Can we turn the garage door into a window?
If the house is covered by the 1988 Article 4 direction and the garage faces the street, you need planning permission first. Ask the council to confirm whether your address is included.
Should we raise the garage floor in Boston?
In most cases we would, to match the house. It's warmer and puts the room a little higher. Your builder and building control will agree the detail once they've seen the existing slab.
We live in a bungalow off Carlton Road. Is a garage bedroom a bad idea?
Not always, but there's no upstairs to go to if water ever gets in. We'd lean towards a study or utility in the garage and keep bedrooms where they are, unless your flood risk is low and you've checked it.
Can we let the converted garage as a separate flat?
That goes well beyond a conversion. A separate dwelling may need planning permission whatever the works, and in the higher hazard flood areas the local plan won't support new self-contained ground floor homes created by a change of use.