How long a modular building takes from order to keys
A Class 3 garden office takes 4 to 6 weeks from order (including 3 to 7 days on site). A 32 to 45 m² Class 3A turnkey garden dwelling takes 6 to 10 weeks in total: 14 days prior council notice, 4 to 8 weeks factory fabrication running in parallel with groundworks, and 1 to 3 weeks on-site commissioning.
Every stage in order, from site survey and council notice to crane day and handover.
Free, no obligation. One vetted modular supplier covering your county prices it, not five.
Stage-by-stage timeline for a modular build
| Stage | Class 3 garden room (up to 30 m²) | Class 3A garden dwelling (32–45 m²) | Standalone modular home (45 m²+) |
|---|---|---|---|
| 1. Site survey, spec & contract | Week 1 | Week 1 to 2 | Weeks 1 to 4 (drawings) |
| 2. Planning / council notice | None (exempt if within Class 3) | 14-day written notice to council | 8 to 16+ weeks planning & BCAR |
| 3. Factory manufacture | Weeks 2 to 5 | Weeks 3 to 8 | Weeks 1 to 10 after planning |
| 4. Foundations & service trench | 1 to 2 days (ground screws) | 3 to 5 days (screws/slab + trench) | 2 to 3 weeks (slab + connections) |
| 5. Delivery, crane/assembly & fit-out | 2 to 5 days on site | 3 days (volumetric) to 3 weeks (panelised) | 1 to 4 weeks on site |
| Total from order to keys | 4 to 6 weeks | 6 to 10 weeks | 4 to 7 months (incl. planning) |
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
When do I submit the 14-day Class 3A notification to the council?
Submit it at least 14 days before any groundworks or foundation installation starts in your garden. Because factory fabrication takes 4 to 8 weeks, you can send the council notification right after ordering so the 14 days pass well before the groundworks crew arrives.
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.