# Garage Conversion Structural Engineer Dublin | Infill & Floors > Garage conversion structural engineer in Dublin: door infill wall and foundation, lintels, floor build-up and openings into the house. Fixed fee in writing. URL: https://structuralengineer.ie/garage-conversion-structural-engineer/ # Garage Conversion Structural Engineer in Dublin The infill wall where the garage door was, the foundation under it, the floor that turns a garage slab into a room, and any opening through to the house. [Call 01 270 9764](tel:+35312709764) [Get a fixed fee](#quote) _Image: Blockwork infill wall being built across a former garage door opening on an Irish estate house_ - I.S. EN 1992-1-1 Concrete design - I.S. EN 1996-1-1 Masonry design - I.S. EN 1997-1 Geotechnical design - TGD A Structure - TGD C Moisture - TGD L Energy Last updated: 14 October 2026 · Reviewed by Joachim Louw, CEng MIEI [StructuralEngineer.ie](https://structuralengineer.ie/) is a Chartered garage conversion structural engineer for homes in Dublin, Kildare, Meath and Wicklow. Most integral and attached garages in 1990s and 2000s estates convert well. The structural work sits in four places: the new wall where the garage door was, the foundation it stands on, the lintel or beam over any new window or door, and the opening through to the house if the garage is joining the kitchen. Irish cost guides put a garage conversion at €15,000–€45,000 in total. The engineering is a small share of that, and the fee is fixed in writing before the visit. ## What happens on the first visit On the first visit the engineer checks what the garage door opening is carrying, what the infill wall will stand on, and what the existing floor slab is like. If the garage is opening into the house, the dividing wall is checked as a possible load-bearing wall too. - Check the lintel or beam over the garage door and what sits on it, often a bedroom above - Look at the existing kerb or footing under the door opening - Check the garage slab level against the house floor, and look for cracks and damp - Check whether the wall between garage and house is load-bearing - Note drains and services running through the garage - Agree window and door positions in the new infill wall ## The infill wall and its foundation Garage door openings usually have a shallow kerb or nothing at all across the threshold, because the doorway wasn't designed to carry a wall. A new cavity infill wall needs a foundation designed for it, often a short strip footing tied into the existing foundations at each side, inspected before it is concreted. The existing lintel or steel over the door was sized for the door opening. It stays, but the engineer checks that it suits the new wall and any window below it, and specifies how the new wall is tied in at the reveals. ## Turning a garage slab into a habitable floor Garage floors are often a step down from the house, with no insulation and sometimes no damp-proof membrane. The new floor build-up of insulation, screed or a raised timber floor has to meet Technical Guidance Document L for energy and Part C for moisture. Where the slab is cracked or uneven, the engineer checks whether it is sound enough to build on or needs breaking out. ## Planning and Building Regulations for garage conversions Converting an integral or attached garage to a habitable room is often treated as exempted development under Class 1 of the Planning and Development Regulations, because it counts towards the extension allowance. Estate conditions and front-elevation changes can affect that, so a Section 5 declaration from your council is the safe way to confirm it. The Building Regulations apply in full: structure, fire separation where the garage adjoins the house, ventilation, energy and moisture. The engineer's opinion of compliance with Part A covers the structural side when you sell. ## What's included - Site visit by a Chartered Engineer - Infill wall and foundation design - Lintel and opening checks for new windows and doors - Load check on the garage-to-house wall - Floor slab assessment and build-up advice - Calcs and marked-up drawings - Inspection of the infill foundation before concrete - Signed opinion of compliance with Part A Typical market range: **€15,000–€45,000** (garage conversion, total; engineering is a small share). Source: onlinetradesmen.ie, 2026. Fixed fee confirmed in writing before the visit. ## Builder's standard infill, online calcs or an engineer on site The infill foundation and the opening into the house are where garage conversions go wrong. | Check | Builder's standard detail | Online calcs, no visit | Chartered Engineer on site | | --- | --- | --- | --- | | Foundation under the infill wall designed | assumed | assumed | Yes | | Existing door lintel checked for the new wall | No | assumed | Yes | | Garage-to-house wall checked if opened | No | No | Yes | | Slab condition assessed on site | No | No | Yes | | Foundation inspected before concrete | No | No | Yes | | Certificate a buyer's solicitor will accept | No | limited | Yes | Sources - [OnlineTradesmen.ie: garage conversion costs](https://www.onlinetradesmen.ie/AMP_EDN/5129/create-space-you-need-617.amp.html) - [Kelleher Associates: 2026 planning exemption regulations](https://www.kelleherassociates.ie/new-2026-planning-exemptions-regulations-come-into-effect/) Talk to the engineer 01 270 9764 Mon–Fri 8:00–18:00. Callback the same working day. [Call now](tel:+35312709764) Fixed fee confirmed in writing before the visit. Standards we design to - I.S. EN 1992-1-1 Concrete design - I.S. EN 1996-1-1 Masonry design - I.S. EN 1997-1 Geotechnical design - TGD A Structure - TGD C Moisture - TGD L Energy Before you book: costs and rules - [Garage Conversion Cost in Dublin (2026)](https://structuralengineer.ie/guide/garage-conversion-cost-dublin/) - [45m2 Extension Exemption: What Changed in July 2026](https://structuralengineer.ie/guide/45m2-extension-exemption/) - [How Much Does a Structural Engineer Cost in Dublin? (2026)](https://structuralengineer.ie/guide/structural-engineer-cost-dublin/) How the job runs ## How a garage conversion is designed and signed off - 01 ### Call and fixed quote Describe the garage and the room you want. You get a fixed fee in writing. - 02 ### Site visit Door opening, threshold, slab, the garage-to-house wall and drains are checked. - 03 ### Design Infill wall, foundation, lintels and any opening into the house, with calcs and drawings. - 04 ### Inspection and sign-off The foundation is inspected before concrete, then the signed opinion of compliance is issued. Converting the garage? Get the infill wall and foundation designed first. Fixed fee confirmed in writing before the visit. [Call 01 270 9764](tel:+35312709764) [Request a fixed fee](#quote) Questions ## Garage conversion engineer: common questions **Do I need a structural engineer for a garage conversion?** For the infill wall foundation, any new openings and any wall knocked through to the house, yes in practice. These are structural items under Building Regulations Part A, and the buyer's solicitor will want an engineer's opinion of compliance when you sell. A conversion that only insulates and lines the garage, with no structural changes, needs less engineering. **Do I need planning permission to convert my garage?** Often not. Converting an integral or attached garage is commonly treated as exempted development, counted against the rear extension allowance. Estate planning conditions and changes to the front of the house can change that, so a Section 5 declaration from your council confirms it in writing. **Can the garage door lintel stay?** Usually yes. The existing lintel or steel over the door already carries the wall or bedroom above. The engineer checks it against the new infill wall and any window opening in it, and details how the new wall is tied in at the sides. **What happens to the garage floor?** Garage slabs are usually lower than the house floor and uninsulated. The new build-up of insulation, damp-proof membrane and screed or timber floor brings it level and meets Technical Guidance Documents C and L. Cracked or uneven slabs are assessed first, and some need breaking out. **What areas do you cover?** Dublin and the Greater Dublin Area (Kildare, Meath and Wicklow). Site visits are booked from the Blackrock office. Site visit usually within 5 working days. ## Related services [### Extensions Foundations, steel and BCAR sign-off for rear and side extensions, including the new 45 m² exemption.](https://structuralengineer.ie/structural-engineer-for-extensions/) [### Load-Bearing Wall Removal Steel beam and padstone design, propping, inspection and a signed certificate for knock-throughs.](https://structuralengineer.ie/load-bearing-wall-removal/) [### Opinions of Compliance Engineer's certificate for past works when you sell, remortgage or regularise an extension.](https://structuralengineer.ie/opinion-of-compliance/) Next step Get a fixed fee for your garage conversion Call [01 270 9764](tel:+35312709764), or send the details and we'll call you back. Request a fixed engineering fee Prefer to talk? [Call 01 270 9764](tel:+35312709764). A live person answers during office hours.