House Extensions and Conversions in Ireland
Looking for a house extension in Ireland? Post your job on ShamFix for free and get quotes from local extension builders — house extensions, attic and garage conversions and extension design. Compare profiles and choose who to hire.
What shapes the price of home extensions and conversions
- Volume is the first driver: a single-storey rear extension of a set floor area costs less than a two-storey side extension with the same footprint because of extra structural work, scaffolding, and roof.
- Access matters in Irish towns and rural sites alike: narrow side entrances, shared driveways, overhead cables, and sloped ground can add labour and plant time.
- Condition of the existing house is another factor: older stone or block walls, damp, subsidence, or a roof that needs altering before the extension ties in.
- Materials and specification change the figure too, from standard block and render to brick, timber frame, or large glazing.
- Conversion costs depend on whether the space is already serviced, whether head height allows insulation and a floor build-up, and whether a new stairs, bathroom, or kitchen is included.
- A builder may charge separately for design, structural calculations, and building control fees, so ask for these to be itemised rather than bundled into one figure.
How long home extensions and conversions takes
A typical single-storey extension takes several weeks on site once foundations are in, with two-storey work and complex conversions running longer. The full process from first enquiry to completion often spans months, because design, planning permission where required, building control, and material lead times come before groundworks. Conversion of an attic or garage can be quicker if the structure and services are straightforward, but it still depends on access and on how much of the existing fabric must be opened up. Realistic start dates depend on the builder's current schedule and on when any permission or certification is in place. Ask for a start window in writing and treat it as an estimate rather than a guarantee, since Irish weather and supply chains can move it.
What to ask before you hire
- 01Ask for a written quote that separates labour, materials, plant hire, waste removal, and VAT, so you can compare like with like.
- 02Ask whether the price is fixed or subject to remeasure, and what would trigger a variation.
- 03Ask which professional body they are a member of, and whether they carry insurance that covers extension and conversion work, including public liability and, where relevant, employer's liability.
- 04Ask for the policy numbers and check they are current.
- 05Ask who is responsible for building control compliance, structural calculations, and any certification needed for the work.
- 06Ask who tidies up at the end of each day and who removes rubble and surplus materials.
- 07Ask what deposit is expected and how payments are staged against progress.
- 08Ask for a written programme with start and finish dates, and ask what happens if the weather or a supply delay pushes those dates back.
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House extensions and attic conversions in Ireland
With high house prices, many families in Dublin, Cork, Galway and commuter counties extend or convert instead of moving. Single-storey rear extensions up to 40 square metres can be exempt from planning permission if they meet set conditions, while larger, two-storey or front extensions usually need planning. An attic can only be counted as a habitable room if it meets Building Regulations on fire safety, stairs and head height, otherwise it is classed as storage. Projects are typically planned over winter and built from spring. When you post a task, describe the house, the size and use of the space you want, whether you have drawings or planning, and your target start date.
Typical extension and conversion jobs
- Single-storey rear kitchen extension
- Two-storey side extension
- Attic conversion to a habitable bedroom
- Attic conversion for storage with Velux windows
- Garage conversion into a living space
- Granny flat or family flat extension
- Sunroom or garden room build
- Dormer window installation
- Ground floor wet room extension
- Architect drawings and planning application
Home extensions and conversions questions people ask
Do I need planning permission for a home extension in Ireland?
Many rear and side extensions fall under exempted development rules, but limits apply to height, floor area, and how close the extension comes to boundaries or the public road. A conversion to a separate living unit usually needs permission. Ask your builder or a planning consultant to confirm the position for your exact house before work starts.
How long does a home extension take to build?
A straightforward single-storey extension often takes several weeks on site after foundations, while two-storey extensions and full conversions run longer. The whole project from design to completion can take months because permission, building control, and material deliveries come first. Get a written programme from your builder and expect weather to affect it.
What is usually included in a written quote for an extension?
A good quote lists labour, materials, plant hire, waste removal, and VAT separately, and states whether the price is fixed or subject to remeasure. It should also say who handles structural calculations, building control, and certification. If design or planning fees are extra, ask for those in writing too.
Can I convert my attic or garage without moving out?
Often yes, because the work is contained and the house stays habitable for much of the job. Dust, noise, and temporary loss of a bathroom or storage can still be disruptive. Ask the builder how they will protect floors, stairs, and living areas, and how they will manage access to the rest of the house.
Who is responsible for clearing rubble and cleaning up after the work?
Responsibility should be agreed before work starts and written into the quote. Most builders remove construction waste, but confirm whether the price includes a skip and final clean. Ask who tidies up each day and who disposes of surplus materials, so there is no surprise cost at the end.
What insurance should a builder have for extension work?
Ask for current public liability insurance and, if they employ others, employer's liability insurance. Request the policy numbers and check the cover is valid for the type and scale of your project. Also ask whether the work is covered for structural defects, and keep copies of the documents for your records.
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