The full dormer project timeline
From 'I'm considering it' to 'it's there': 3-6 months without permit, 4-8 with. Many owners underestimate lead times, especially the installer queue and permit procedure. Plan ahead, especially for summer installs.
- Total without permit
- 3-6 months
- Total with permit
- 4-8 months
- Permit procedure
- 8 weeks regular, 26 weeks extended
- Installer queue
- 4-12 weeks (peak May-Sept)
- Prefab production
- 3-6 weeks after contract
Month 1: orientation and quotes
Week 1: self-orient (websites, examples in your street), define wishes (size, material, side). Weeks 2-3: 3-5 quotes from different companies (prefab supplier, local builder, dormer specialist).
Week 4: compare on price, warranty, references and chemistry. On doubt ask for reference addresses and call 2-3 past customers. Avoid pressure to sign fast — the best companies have queues and don't need this pressure.
Month 2: choice, contract and permit
Sign contract with 10-30% deposit standard. Permit application via Omgevingsloket — installer or architect usually does this, €450-€1,500 including drawings.
If permit-free: skip this step, go directly to month 4. Always request written confirmation of permit-free status from your municipality before build.
Months 3-4: municipal review and production
Municipality reviews 8 weeks (regular) or 26 weeks (extended, listed/protected). During this period the prefab factory starts production as soon as contract is signed — 3-6 weeks lead.
After grant, a 6-week objection period still runs. Pragmatic installers start production during this period if you sign a risk acceptance; waiting for 'irrevocable' is safer but 6 weeks later.
Months 4-6: queue, install and handover
Popular installers have 4-12 weeks queue after 'ready to build'. May-August peak (16+ weeks not unusual). November-February shortest (2-4 weeks).
Install itself 1-5 days. Interior finishing 1-3 extra days over 2 weeks. Handover with signature, warranty certificates and final invoice (70-90%).
FAQ
- Can I speed up the timeline?
- Limited. Choosing prefab saves 1-2 weeks build, pre-consultation saves 2-4 weeks permit, winter install saves 6-10 weeks queue.
- Summer or winter install?
- Summer (May-Sept) is popular but busy; longer queues. Winter (Nov-Feb) has shorter queues and equal prices but some rain risk on open roofs. Spring is the sweet spot.
- How much buffer should I plan?
- 10-20% above minimum. To target 'before summer' start with quotes in January.
- What do neighbour objections do to the timeline?
- +12-26 weeks for municipal review, on court appeal another +6-12 months.
- Can I postpone install after contract?
- Usually yes by 4-8 weeks pre-production; afterwards costs accrue (prefab storage €100-€200/week).