Garden offices and insulated garden rooms in Ireland
An insulated, wired and lined garden office of 12 to 16 m² costs €18,000 to €32,000 supplied and fitted (including 13.5% VAT), and a larger 20 to 30 m² garden room or gym costs €28,000 to €55,000. Since 27 July 2026 (S.I. No. 338 of 2026), the Class 3 planning exemption limit for non-habitable garden rooms is 30 m² (up from 25 m²).
Year-round insulated garden offices, gyms and music studios up to the 30 m² Class 3 limit.
Free, no obligation. One vetted modular supplier covering your county prices it, not five.
Configure your size, cost and planning exemption
Pick your floor area, specification and use. Shows our 13.5% VAT price guide and whether your build falls under Class 3 (up to 30 m² non-habitable) or Class 3A (32 to 45 m² habitable garden dwelling, S.I. No. 340 of 2026).
Guide price (incl. 13.5% VAT) & planning status
€40,000 to €60,000
Class 3 Exempt (25 m² ≤ 30 m² limit)
Based on 25 m² at our insulated & fitted room guide rate of €1,600 to €2,400 a m² (including 13.5% VAT on supply and installation). Exempt from planning permission under Class 3 (S.I. No. 338 of 2026, raised from 25 m² to 30 m² on 27 July 2026), provided it sits behind the front wall of the house, total garden structures do not exceed 30 m², at least 25 m² of private open space remains, height is within 3 m (flat roof) or 4 m (pitched), and it is not used for human habitation.
Send this for a written quoteGarden office and room prices by size
| Footprint | Typical dimensions | Suits | Insulated & fitted (13.5% VAT) |
|---|---|---|---|
| 9 to 12 m² | 3 × 3 m or 4 × 3 m | 1 to 2 person home office or therapy room | €16,000 to €26,000 |
| 15 to 16 m² | 5 × 3 m or 4 × 4 m | Office + sofa / meeting space or home gym | €18,000 to €32,000 |
| 20 to 25 m² | 5 × 4 m or 6 × 4.2 m | Gym + office split, teen den or music studio | €28,000 to €48,000 |
| 30 m² (Class 3 max) | 6 × 5 m or 7.5 × 4 m | Largest planning-exempt non-habitable room | €35,000 to €55,000 |
Five things that separate an all-year room from a summer shed
- Wall, roof and floor insulation. At least 100 mm PIR or structural insulated panels (SIPs) / mineral wool in the walls, roof and floor, with a breather membrane outside and vapour barrier inside so condensation cannot form.
- Residential-grade glazing. Argon-filled A-rated double or triple glazing in uPVC or thermally broken aluminium frames, with multi-point locks.
- Proper foundations. Ground screws ({r(BASE_SCREW)} a m²) or a concrete base that keeps the floor structure clear of wet soil and allows airflow underneath.
- Dedicated electrical sub-board. An armoured SWA cable trenched from your house fuse board to a dedicated consumer unit in the garden room, certified by a Safe Electric registered electrician, plus Cat 6 ethernet run in the same trench for rock-solid broadband.
- Low-maintenance exterior. Composite cladding, cedar, thermowood or architectural steel with an EPDM rubber or standing-seam metal roof carrying a 20+ year membrane warranty.
What modular buildings cost in Ireland
Our price guide by size and specification, including 13.5% VAT on supply and installation.
| Job | Typical cost | What moves the price |
|---|---|---|
| Insulated garden office or studio, 12 to 16 m² (Class 3) | €18,000 to €32,000 | Cladding, glazing, base and cable run from the house |
| Large garden room or gym, 20 to 30 m² (Class 3 max) | €28,000 to €55,000 | Up to the 30 m² non-habitable exemption limit; no plumbing or kitchen |
| Class 3A habitable garden dwelling, 32 to 37 m² (1-bed) | €65,000 to €105,000 | Kitchen, shower room, Building Regs insulation, base and service hook-ups |
| Class 3A maximum garden dwelling, 40 to 45 m² (1 to 2 bed) | €80,000 to €135,000 | Largest exempt rear-garden unit (45 m² total garden structures cap) |
| Standalone 2 to 3 bed modular home, 75 to 85 m² | €175,000 to €255,000 | Full planning permission, BCAR, foundations and site services |
| Factory shell only (weathertight exterior), per m² | €1,200 to €1,800 a m² | Excludes groundworks, internal plumbing/kitchen and service connections |
| Insulated & fitted garden room rate, per m² | €1,600 to €2,400 a m² | Includes 13.5% VAT when supplied and installed by the builder |
| Turnkey habitable modular home rate, per m² | €2,400 to €3,200 a m² | All-in with kitchen, bathroom, foundations and 13.5% VAT |
Get a modular building price in 4 taps
Tap what you want to build, the size and your county. Your request goes to one vetted modular building supplier that covers your county, and they ring you with a written specification and price.
Questions people ask
Can I put a toilet in a Class 3 garden office?
A small WC/washbasin in a home office or gym is sometimes requested, but adding a shower, kitchen and bed turns the structure into habitable accommodation — which is not allowed under Class 3 (up to 30 m²) and must instead meet the 32 to 45 m² Class 3A garden dwelling rules or have planning permission.
How close to the boundary fence can a garden room go?
Planning exemption rules don't set a boundary setback for Class 3, but keeping 500 mm to 1 m clear of fences and walls gives the crew room to fit cladding and gutters and prevents roof overhang or rainwater discharging onto a neighbour's property.
Get a written turnkey price for your modular building
One vetted supplier covering your county checks access, foundations and service connections, and gives you a written price.