Steel BeamInstallers
Garage conversion with the old door opening being bricked up around a new window

Garage conversion openings · Lisburn

Garage conversion openings in Lisburn

Steelwork, approvals and making good for garage conversion openings in Lisburn and nearby.

  • Price fixed in writing once scope is agreed
  • Building control arranged
  • Temporary works and making good included

Free survey in Lisburn

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  • Free survey visit
  • Engineer's calculations arranged
  • Building control handled
  • Fixed written price once scope is agreed
  • England, Wales, mainland Scotland & NI

Planning garage conversion openings in Lisburn

We carry out garage conversion openings in Lisburn, covering the BT17, BT27 and BT28 postcode districts. We also cover the surrounding towns and villages in Lisburn and Castlereagh. The job starts with a free survey visit so the engineer's calculations are based on your actual walls, floors and loads.

Converting a garage is a popular way to add a room without extending. Structurally, two things usually happen: the big garage door opening is filled in with a wall, window or door on proper foundations, and a doorway or wider opening is formed through the wall between the garage and the house.

Key points for your project

  • Garage floors often sit lower than the house floor and may have no damp-proof membrane. The infill wall needs a damp-proof course linked to the existing walls, and the floor usually needs a membrane, insulation and screed raised to the house level.
  • Garages built before 2000 can contain asbestos cement in roof sheets, wall panels or the garage door itself. A survey of the materials being disturbed is needed before work starts, so any asbestos can be removed or managed correctly.
  • A converted garage used as a bedroom needs a suitable means of escape, often an escape window, and every habitable room needs ventilation. These affect the size and type of window in the infill wall, so they are agreed before brickwork starts.
  • An integral garage is usually separated from the house by fire-resisting construction. If part of it stays as a garage or store, that separation must be kept, and any new door between garage and house normally needs to be a fire door.
  • The price depends on whether the garage door beam needs replacing, the foundation needed for the infill, whether a new opening is formed into the house, the brick or cladding finish, and any fire separation work that has to be kept or added.

What happens, step by step

  1. Free visit

    A short visit to Lisburn to see the job, agree what you want and check the bearings, floors and services that affect the design.

  2. Calculations

    The engineer's calculations and a simple drawing are prepared for your opening and shared with you before anything is ordered.

  3. Building control

    A full plans application or building notice goes to Lisburn and Castlereagh City Council under the Building Regulations (Northern Ireland) 2012 before work begins.

  4. Steel in, made good

    On site we prop, open up, fit and pack the steel, then fire protect, box in and plaster once the inspection is done.

How much should I budget in Lisburn?

As a guide, budget £860–£2,580 including VAT for garage door opening infill (structural part) in Lisburn, based on published UK cost guides adjusted for prices in Northern Ireland (-14%).

JobTypical guide rangeWhat it usually covers
Garage door opening infill (structural part)£860–£2,580Beam or lintel checked or replaced, foundation and infill wall for the old door opening (window and finishes extra)
Steel beam replacement£1,700–£4,750Propping, removing the failed beam, new steel on proper bearings, approval and making good
Structural calculations for a beam£220–£640Site measure or photos, beam and padstone design and calculations for building control
Lintel replacement£340–£1,030 per lintelPropping, removing the old lintel, new lintel set on beds and brickwork made good

Figures include our approximate regional adjustment for prices in Northern Ireland (-14%) and are rounded. How these figures are worked out.

Building control and neighbours in Lisburn

Building control in Lisburn is run by Lisburn and Castlereagh City Council. Beams and new openings are controlled work under the Northern Ireland regulations, so we apply before anything is removed and the steel is inspected before it is covered.

Northern Ireland has no Party Wall Act, so there is no statutory notice to serve. Where the steel bears into a shared wall, the title deeds and the general law apply, and agreeing the work with your neighbour in writing first is good practice.

Building rules in Northern Ireland

Garage conversion openings near Lisburn

Local questions answered

Who approves garage conversion openings in Lisburn?

Structural work in Lisburn needs a full plans application or building notice to Lisburn and Castlereagh City Council. We prepare and submit it with the structural engineer's calculations and arrange the inspections, so the completion paperwork follows the job.

How much do garage conversion openings cost in Lisburn?

As a guide, budget £860–£2,580 including VAT for garage door opening infill (structural part) in Lisburn, based on published UK cost guides adjusted for prices in Northern Ireland (-14%). The exact figure depends on the span, what the wall carries, access and the finish, and is fixed in writing once the scope is agreed.

Does the infill wall need foundations?

Yes. A new masonry wall across the garage door opening needs a proper footing, as the existing garage slab is usually not designed to carry it. A trench is dug across the opening and a foundation is formed to the engineer's and building control's requirements, then inspected before the wall is built.

Is my garage floor suitable for a living room?

Rarely as it stands. Garage floors are often lower than the house, may slope towards the door and usually lack insulation and a damp-proof membrane. The floor is normally built up with a membrane, insulation and screed or a timber floor to meet the house level and the building regulations.

What happens to the beam over my garage door?

It is checked by the engineer. Many can stay, carrying the wall above as before, with the infill built underneath. If it is timber that has rotted, a corroded steel section or simply undersized for the loads, it is replaced, with the wall or room above propped while the new steel goes in.

Do you also work near Lisburn?

Yes. We also cover nearby towns including Castlereagh, Newtownabbey, Newtownards and Craigavon.

Planning to take a wall out?

Book a free survey visit. You get an itemised written quote covering calculations, building control, steel and making good.