Replacing an existing dormer
On replacement the original position and (often) size stay; only the build is renewed. Permit often not required (if no size change, not a listed building). Replacement runs €5,500-€9,000 plus old demolition.
- Replacement price range
- €5,500-€9,000 (3-4 m)
- Old dormer demolition
- €600-€1,200 incl. removal
- Permit required
- Usually no (at same size)
- Build time
- 2-4 days (demo + install + finish)
- Asbestos inventory
- Mandatory before demolition for dormers <1994
How it differs from new install
No opening to cut (already exists), but demolition of the old dormer (€600-€1,200 including removal). Faster or permit-free procedure.
Structure needn't be re-evaluated if size is identical. But: all junctions (lead, insulation, interior finish) are fully renewed. With prefab same-day install possible (demo morning, new in afternoon).
The demolition process
Day 1 morning: interior finish and frames removed, roof covering opened, old dormer skeleton lifted out by crane. Lead and zinc collected for recycling.
For asbestos-containing dormers (houses <1994 with asbestos sheathing): asbestos inventory mandatory beforehand (€350-€600), removal by certified firm (€1,500-€3,500). Don't DIY — legal requirement.
What to do with the old dormer
PVC: barely any return at the recycling centre; the installer recycles. Timber: often a second life via reuse channels (frames can go to Marktplaats or building reuse shops).
Lead: scrap value (€2-€4/kg) — a 3 m dormer yields €40-€120 in lead money. Confirm with the installer that removal is in the quote or if you must arrange a skip (€250-€450).
Upgrades to bundle with replacement
Often the moment for upgrades: HR++ to triple glass (+€400-€700, U 0.7 vs 1.1), R 3.5 to R 6.5 insulation (+€350-€600 against €350/yr heating savings), or shading integration (€800-€1,800).
Size increase at the same time: 2 m to 3 m costs +€2,000-€3,500 extra vs same size — relatively cheap since all peripheral work (permit, roof, crane) is done anyway. Request both variants quoted.
FAQ
- Is replacement permit-free?
- Usually yes, if size and position stay equal, not a listed building and not in a protected view. Check with municipality if uncertain €0-€100.
- Do I get a discount vs new install?
- Sometimes €500-€1,000 less than full new (no opening to cut, often no permit). But add demolition €600-€1,200 — net roughly equal total.
- How long is the roof 'open' during replacement?
- Prefab same-day: 3-5 hours. Traditional with demolition: 2-3 days with tarp overnight.
- What does replacement do to property value?
- Marginally positive: a well-kept dormer keeps WOZ stable; a dated dormer can lower WOZ 3-5%. Replacement neutralises this.
- Can I keep items in the loft during demolition?
- Better not. Expect heavy demolition with dust and possibly water. Empty the loft completely or sheet everything.