Castlederg · County Tyrone

Extensions over a garage in Castlederg

For an extension over a garage in Castlederg, the first questions are always the same: how big, which approvals, and what it will cost. This page answers all three for County Tyrone.

Useful details for planning an extension over a garage in Castlederg.

Postcode districts
BT81
County / area
County Tyrone, Northern Ireland
Price region
Northern Ireland
Guide price
£27,500–£40,500 (£1,540–£2,240 per m²)
Approval route
Planning permission is needed: permitted development side extensions in Northern Ireland can't be more than 4 m high, which rules out two storeys.
Nearest towns
Sion Mills (7.4 miles), Strabane (9.5 miles), Omagh (13.9 miles)
Distance to Omagh
about 13.9 miles
First visit
Free, no obligation

About an extension over a garage

An extension over a garage is a new first-floor room built on top of an existing attached garage, usually a bedroom, en-suite or study. It uses a footprint you already have, so it adds floor space without taking any garden. The garage walls and foundations often need strengthening or replacing to carry the new floor.

We cover postcode district BT81 in and around Castlederg, along with neighbouring Sion Mills, Strabane and Omagh.

What it costs in Castlederg

Using our Northern Ireland rates, an extension over a garage with 3 m × 6 m of new first-floor space (18 m²) comes to about £27,500–£40,500, including VAT. Bigger or more glazed designs cost more per m². The fastest way to a firmer number is a free site visit, after which we price the design stage in writing.

SpecPer m²3 m × 6 m of new first-floor space (18 m²)
Essential£1,420–£2,060 per m²£25,500–£37,000
Standard£1,540–£2,240 per m²£27,500–£40,500
Premium£1,850–£2,690 per m²£33,500–£48,500

Planning and building control in Castlederg

In Northern Ireland, permitted development for two-storey work is set out for rear extensions, so building over a side garage normally needs a planning application, which costs £347 per dwelling. Councils aim for an average of 15 weeks for local applications. Building control approval is also needed, including fire separation if the garage stays in use.

Approval in Northern Ireland: Planning application for works to a house: £347. Councils aim to decide local applications within an average of 15 weeks; many take longer.

Building control: Building control approval from the local council under the Building Regulations (Northern Ireland), using the Technical Booklets.

Design points for Castlederg homes

Matching the house

A room over a garage usually sits beside the front of the house in full view, so roof form, ridge height, windows and brick matter. Setting the front wall and ridge back slightly from the main house usually helps it look as if it belongs.

Checking the garage foundations

Garages are often built on shallow strip footings sized for a single-storey wall and a light roof. A trial hole shows their depth and condition, and the engineer decides whether they can carry two storeys or need underpinning or new foundations inside the garage.

How we'd run your project

  1. Look at the house

    We start in Castlederg with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.

  2. Plans, then approval

    Measured survey, design, then the right approval route for your house. We explain each step before we take it.

  3. Structure and building control

    A structural engineer sizes the foundations and steels, and we get building regulations approval before work starts.

  4. Build and hand over

    We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.

Questions about extensions over a garage in Castlederg

Do I need planning permission for an extension over a garage in Castlederg?

Castlederg is in Northern Ireland. Planning permission is needed: permitted development side extensions in Northern Ireland can't be more than 4 m high, which rules out two storeys.

Which postcodes do you cover around Castlederg?

We cover Castlederg (BT81) and nearby places including Sion Mills, Strabane and Omagh, plus the rest of County Tyrone. The first site visit is free.

How much does an extension over a garage cost in Castlederg?

Our guide for Northern Ireland, which covers Castlederg, is £1,540–£2,240 per m² including VAT. A typical project with 3 m × 6 m of new first-floor space (18 m²) comes to about £27,500–£40,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

How do I get into a room over the garage?

Usually through a new opening off the existing landing or a bedroom, so the stairs stay where they are. If the floor levels do not match, a step or two may be needed inside the new room. Where a landing opening is not practical, a new stair from a converted garage is an option.

Do I need to convert the garage as well?

No. You can keep the garage for parking or storage and build only the room above, as long as the floor between them and any door into the house meet fire separation rules. Converting the garage at the same time is often good value, because the walls and foundations may be upgraded anyway.

Nearby

We also cover places near Castlederg, including:

Other extensions in Castlederg

All two-storey extension services in Castlederg · Extensions over a garage across County Tyrone

Book a free site visit in Castlederg and we'll tell you what's possible, what approvals you need and what the design stage would cost.

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