Average Cost of House Extensions, Renovations & Home Upgrades in Ireland 2026

Irish building costs remain elevated. The CSO reported that construction-product prices were 3.3% higher in July 2026 than a year earlier, while its combined Building and Construction Index, covering materials and wages, was 3.4% higher. Read our full guide to building material costs in Ireland in 2026 for a breakdown of concrete, copper, plaster, insulation, steel and other key materials.

There is no fixed national price for an extension or renovation. Location, drawings, access, ground conditions, structural steel, glazing, kitchens, bathrooms, heating and the standard of finish can move the final quotation significantly.

House Extension Costs Ireland 2026

For early budgeting, Trade Source IRE uses an indicative range of approximately €2,200–€3,900 per m² for many single-storey house extensions. Premium finishes, major structural alterations, restricted access and high-cost urban projects can exceed this range.

These are early build-cost estimates, not complete project quotations. Professional fees, kitchens, specialist glazing, utility alterations, flooring, landscaping, VAT and unforeseen works may be additional. For a deeper breakdown, read our complete house extension cost guide for Ireland 2026.

What pushes an extension quotation higher?

A straightforward block-built rear extension with standard finishes will generally cost less than an open-plan kitchen extension requiring RSJs, large sliding doors, rooflights, underfloor heating and bespoke joinery.

Your overall budget may need to include:

• Architectural or architectural-technologist drawings
• Structural engineering
• Foundations and groundworks
• Steel beams and temporary supports
• Windows, external doors and rooflights
• Kitchen and utility-room fitting
• Plumbing, heating and electrical work
• Plastering, flooring and decorating
• Skip hire, scaffolding and waste removal
• BER improvements and ventilation
• Planning and Building Control requirements
• VAT and a contingency for unforeseen work

Do You Need Planning Permission for an Extension?

Since 27 July 2026, a rear house extension of up to a total relevant floor area of 45 m² may qualify as exempted development. However, the exemption is not automatic.

Previous extensions count towards the total, while detailed limits also apply to height, boundaries, windows, upper-floor areas and the amount of private open space remaining. Building Regulations and Building Control requirements can still apply even when planning permission is not needed.

Check our Planning Permission Ireland 2026 guide before appointing a builder or ordering materials.

House Renovation Costs Ireland 2026

A renovation can mean anything from redecorating and replacing finishes to a complete strip-out, rewire, replumb, layout change and energy retrofit.

Buildcost’s First Half 2026 Construction Cost Guide provides the following general refurbishment benchmarks:

Buildcost states that its benchmark rates exclude items such as VAT, siteworks, professional fees, furniture, fittings, equipment, developer overheads and abnormal costs. Its Second Half 2026 guide places refurbishment and fit-out works to existing Georgian buildings at approximately €4,000–€6,000 per m², illustrating how protected, period and complicated properties can cost considerably more.

Older Irish houses can uncover defective floors, damp, outdated wiring, poor insulation, lead pipework, weak roof timbers or structural movement once opening-up work begins. A measured survey, clear specification and suitable contingency are essential.

For broader project figures, see our builder costs in Ireland 2026 guide.

Popular Home Improvement Costs

Trade Source IRE’s current indicative 2026 budgeting ranges include:

These figures exclude VAT and can rise substantially where the project involves premium fittings, drainage changes, structural work, specialist glazing or a complete relocation of services.

Attic conversion costs

Current indicative attic-conversion figures include:

• Storage-only attic upgrade: €5,000–€10,000
• Rooflight or Velux-style conversion: €18,000–€28,000
• Rear dormer conversion: €40,000–€60,000
• Hip-to-gable or major roof remodel: €55,000–€75,000+

These figures exclude VAT. A storage attic is not automatically suitable for use as a bedroom, and habitable conversions must address structure, stairs, fire safety, insulation, ventilation and electrical requirements. Read our attic conversion costs and 2026 dormer rules guide before starting work.

Home Energy Upgrade Costs Ireland 2026

An extension or renovation is often the best time to upgrade insulation, heating, windows, ventilation or solar PV because walls, floors and services are already being opened.

The latest SEAI individual-upgrade cost report is based on 47,067 grant-supported upgrades completed during 2025. These are national median costs recorded at grant-payment stage—not fixed quotations.

For complete home-energy upgrades delivered through registered One Stop Shops, SEAI recorded a median works cost of €60,805 for a semi-D or end-terrace house and €69,795 for a detached house. The median amounts paid by homeowners after grants were €38,932 and €45,067 respectively. Actual costs and grant support depend on the measures required, technical eligibility and property type.

Before starting grant-supported work, read our SEAI Grants Ireland 2026 guide, BER rating and home energy efficiency guide and home energy upgrades that can save money. SEAI grant approval generally needs to be in place before eligible work starts, and homeowners must follow the registration requirements for the relevant measure.

Remember VAT

Revenue states that the reduced VAT rate generally applies to construction services, including building, extensions, alterations, electrical work, plumbing, heating, plastering, painting, roofing and flooring.

Ireland’s reduced VAT rate is 13.5% in 2026, although the correct treatment can depend on the service, materials and specific tax rules. Your written quotation should state clearly whether VAT is included and which rate applies.

Which Tradesmen Might Your Project Need?

An extension or full renovation rarely involves only one trade. Depending on the work, you may need:

• Builders in Ireland for extensions, renovations, structural alterations and conversions
• Electricians in Ireland for first fix, second fix, rewiring, lighting and consumer-unit work
• Plumbers in Ireland for pipework, bathrooms, heating and hot-water systems
• Carpenters in Ireland for roofs, floors, doors, kitchens and finish carpentry
• Insulation contractors for attic, cavity, internal and external insulation
• Roofing contractors for roof alterations, repairs, slates, tiles and flat roofs
• Tilers in Ireland for kitchens, bathrooms, walls and floors
• Plasterers in Ireland for skimming, dry lining, rendering and repairs
• Window and door specialists for glazing, entrance doors and replacement windows
• Painters and decorators for final finishes and full-property decoration

Browse Specific Tradesmen from the Network

Homeowners can view individual company profiles and examples of completed work through the Trade Source IRE Tradesmen Showcase.

Builders and renovation contractors

Harapu Construction covers Dublin and surrounding counties, with preferred work including extensions, loft conversions, new builds, refurbishments and general building.

Aidan Byrnes Building covers Limerick and the South West for new builds, extensions, renovations, retrofit work and civil construction.

Paul Smyth Building Services lists Dublin, Monaghan and Louth as its main areas for new builds, renovations, extensions and commercial work.

Edal Construction Limited covers Dublin and surrounding counties for extensions, complete home rebuilds, renovations, bathrooms, roofing, plastering and attic conversions.

Energy-upgrade and retrofit specialists

HECO Construction LTD covers Dublin and surrounding counties for internal, external, attic and cavity-wall insulation, ventilation upgrades and retrofit work.

Brusna Energy Solutions covers Sligo and the North West for insulation, heat pumps, ventilation, heating upgrades and complete home-energy retrofits.

Attics, carpentry, windows and doors

UP2U Attics provides attic conversions, attic stairs and garden rooms across Dublin, Kildare, Meath and Wicklow.

Claxton Windows & Doors showcases replacement-window, entrance-door and installation projects across Dublin, Kildare, Meath and Wicklow.

Let Trade Source IRE Do the Legwork

Finding the right team should not be the hardest part of improving your home. Submit one enquiry for an extension, renovation, attic conversion, bathroom, kitchen or energy upgrade and tell us:

• Where the property is located
• The type and approximate size of the project
• Your preferred timeframe
• Your available budget
• Whether you have drawings, planning permission or a BER
• Which trades you require

We review the details and help route the enquiry towards potentially suitable tradesmen where available. You compare quotations, experience and availability—and you decide who to proceed with.

It is free to submit a project, with no obligation to appoint a contractor. Contractors are reviewed before joining the network, but customers should always complete their own insurance, registration, reference and suitability checks.