Dormer installation for space and light in your loft
Want more space and daylight in your loft? A dormer turns your loft into a proper room. We install prefab, PVC and timber dormers, including window frames, insulation and the interior finishing. One dedicated team, one point of contact and a clear price agreed up front.
From a dark loft to a proper room
A dormer looks like a small job, but the roof has to be opened and the joint must be watertight and well insulated. As a dedicated construction company in Rotterdam, we install dormers with one team: the roof is only open briefly, the dormer is finished neatly and you are left with a bright, usable space.
Prefab for speed, PVC for easy maintenance or timber for a classic look: we advise on what suits your home and the local aesthetic-quality requirements. You receive a clear quote up front with a transparent price breakdown, including the permit check.
Request your free dormer adviceOne dedicated team
Our own craftsmen, one point of contact, no miscommunication.
Clear price up front
A clear quote, with no surprises afterwards.
Guaranteed & certified
A guarantee on our work, plus CO certification, STEK, NEN 1010 and VCA.
Local in Rotterdam
Familiar with Rotterdam's homes and the local council.
Recent projects in Rotterdam and the Randstad
A selection of our completed projects. View the full portfolio for more.
What our clients say
We only publish genuine, verified reviews. Our clients' reviews will soon be shown here via Google.
What a dormer installation involves
From choice to finishing: we handle the whole project, with the roof open for just one day where possible.
Prefab dormer
Quickly installed, often in a single day, neatly finished and well insulated.
PVC or timber
Low-maintenance PVC or a classic timber version, the choice is yours.
Frames & windows
Tilt-and-turn windows with HR++ glazing for light and ventilation.
Roof insulation
A well-insulated dormer, warm in winter and cool in summer.
Interior finishing
Walls, window sill and paintwork, neatly finished.
Need more space?
A whole extra floor? Take a look at our roof extension.
How we install your dormer
A tight process in five steps, from advice to handover.
Advice & survey
We visit, take measurements and advise on the type, material and permit.
Quote & schedule
You receive a clear quote with a transparent price breakdown and schedule.
Installation
The roof is opened, the dormer is fitted and connected watertight.
Insulation & finishing
Insulation, window frames and the complete interior finishing.
Handover & guarantee
We walk through everything together and hand over neatly, with a guarantee on the work.
Our own team, no subcontractors
Your entire job handled by our own 20 to 30 craftsmen. Short lines, one point of contact.
One price up front, no surprises
You know where you stand from the outset. No unexpected extra costs afterwards.
1-year guarantee on the renovation
We stand behind our work and are only finished when you are satisfied.
Dormer installation in Rotterdam and across the Randstad
Rotterdamse Bouwbedrijf is at home in Rotterdam, but we install dormers across the whole Randstad. From Rotterdam and Dordrecht to The Hague, Leiden and Amsterdam, and everywhere in between. Don't see your town listed? Do get in touch, we work throughout the region.
And also in, among others
We work with reliable A-brands, for a durable result with a manufacturer's warranty.
Questions about dormer installation
Do I need a permit for a dormer?
How long does installing a dormer take?
Prefab or built on site?
PVC or timber dormer?
Which municipalities do you install dormers in?
Ready for more space in your loft?
Arrange a free, no-obligation consultation. We come to you, discuss the options and draw up a personal plan with a clear price.
What you should know about a dormer
A dormer turns a sloping loft into a proper room. The installation is quick; the quality lies in the insulation and the watertight joint.
Prefab or built on site
A prefab dormer is made in the factory and installed in a single day: fast and with little disruption. Building on site gives more freedom in dimensions and detail. For most homes, prefab is the most efficient choice.
Insulation and the joint with the roof
The gain lies in good insulation of the cheeks and the roof, and in a watertight joint with the existing roof covering. It is precisely at that seam that leaks otherwise develop. We finish the lead flashing and joints with care.
Permit: front or rear
A dormer on the rear roof face is often permit-free; at the front, aesthetic-quality rules usually apply and therefore a permit. We check your council's rules in advance, so you are not caught out by surprises.
Common mistakes
- Too little insulation in the cheeks and roof, giving stifling heat in summer and cold in winter.
- A sloppy joint with the roof covering, causing leaks at the first heavy rain.
- Assuming the front is permit-free, with council enforcement as the risk.
Want a whole extra floor rather than a single room? Then take a look at a roof extension. Replacing the glazing anyway? Combine it with window frames and insulation. Still unsure whether your loft is suitable? Our article on converting a loft into living space explains what to watch for in terms of headroom, floor loading and insulation.