Finishing your dormer inside: complete guide
Most dormer suppliers deliver 'shell-ready' as standard — plasterboard on walls and sloped ceiling, ready for wallpaper or plaster. Between 'shell-ready' and 'move-in ready' lies another €1,500–€4,000 for plaster, paint, flooring, skirting, light points and sockets. Many customers are surprised because this is missing from the standard quote. Honest breakdown below.
- Standard ('shell-ready')
- Plasterboard + vapour barrier, unpainted
- Wall + ceiling plaster
- €700–€1,300 (3-metre)
- Painting 2 coats
- €500–€900 (3-metre)
- Floor finish laminate/PVC
- €450–€800 (3-metre)
- Skirting + trim
- €250–€500
- Extra socket/light point
- €80–€150 each
What's included in a standard dormer quote?
Standard interior at major suppliers (Mr Dakkapel, Hoogenboom, De Vries): 12.5 mm plasterboard on steel profiles, taped seams, vapour barrier behind boards, NO plaster, NO paint, NO flooring, NO skirting. One light point and 2 sockets are often included, sometimes for €150–€250 extra.
Almost always missing: plaster, paint, flooring, skirting, curtain rails, interior windowsills, and connection to existing socket circuit (often needs new fuse group €350–€600 in the meter cabinet).
Plaster or wallpaper-ready?
Standard plasterboard is 'wallpaper-ready' after seam-fill. For paint or thin wallpaper it's too rough — visible joints show. Two options:
Skim coat (1–2 mm): €15–€22/m². For a 3-metre dormer (~22 m² walls+ceiling): €330–€480. Then paint.
Smooth plaster (3–5 mm): €25–€35/m². €550–€770 for same surface. Higher-end result, longer drying (2–3 weeks before paint).
Flooring, skirting and trim
The dormer floor is OSB on the joists. On top: laminate (€20–€35/m² incl. laying), PVC-click (€40–€65/m²), vinyl (€30–€50/m²) or carpet (€25–€45/m²). A 3-metre dormer has 4–6 m² of new floor, plus existing attic.
Skirting: primed white MDF €8–€15/m, painted €15–€25/m. Trim around interior windows €10–€18/m. A 3-metre dormer needs ~10 m skirting and 12 m trim.
Interior windowsill: not standard with PVC frames. Solid surface or wood sill €60–€120/m, mounting €80–€120. A 3-metre dormer ~3 m sill, total €260–€480.
Electrics: don't forget the fuse group
A dormer with 1 light and 2 sockets can usually connect to an existing attic circuit. More (LED spots, screen motors, AC): separate fuse group needed (€350–€600), including RCD.
Adding points in the dormer: €80–€150 per socket, €120–€220 per light/LED spot, €150–€250 per wired thermostat or dimmer switch.
For screen motors or electric awnings: separate 230V supply with empty conduit to control point, ~€150–€250 per screen.
FAQ
- How much above the dormer price for move-in ready?
- Budget €1,500–€4,000 above a 'shell' quote for plaster, paint, floor, skirting and extra sockets. With ambitious finish (solid wood floor, designer lighting) it can reach €5,000+.
- Can I do the interior myself?
- Yes — saves €1,500–€2,500 in labour. Plaster and paint are DIY-friendly. Electrics must be done by a certified installer (NEN 1010) for insurance and warranty.
- How long to wait before painting?
- Skim coat: 5–7 days drying. Smooth plaster: 14–21 days. Paint only when a moisture meter shows <2% in the plaster, otherwise paint peels within 2 years.
- What if I want a vapour-open wall instead of barrier?
- Possible — requires different insulation (wood fibre or cellulose instead of mineral wool) and vapour-open film both sides. €1,000–€2,000 extra. Better for old houses; request a hygrothermal calculation.
- Warranty on plaster and paint?
- From a contractor: 2 years standard on plaster (shrinkage cracks), 1 year on paint. DIY: none. First-winter shrinkage cracks are normal as plasterboard and plaster cure; repair €100–€250.