On top of an existing extension
A floor built on a single-storey extension at the back. 12 to 18 m² extra upstairs, as long as the extension's foundation and walls can take it.
A roof extension for a whole extra floor
Roof extensions and extra floors across Brabant, in English.When a dormer is not enough. A roof extension (in Dutch: dakopbouw) gives your house a complete extra floor, for two bedrooms or a bedroom with its own bathroom. Structure checked and calculated, permit arranged, and the whole job done by one team.
22 years
in the trade
250+
projects delivered
CO-keur certified
STEK registered
NEN 1010 electrical
GPI certified
VCA safety certifiedCO-keur certifiedSTEK registeredNEN 1010 electricalGPI certifiedVCA safety certifiedCO-keur certifiedSTEK registeredNEN 1010 electricalGPI certifiedVCA safety certifiedA complete extra floor
on your own house
A roof extension adds a full floor to your house. On a flat roof we build a new storey on top. On a pitched roof the existing roof often comes off and a full storey with a new roof goes on. Either way, you gain 25 to 40 square metres of real living space: two bedrooms, a master bedroom with an en-suite bathroom, or a home office that is actually separate from the rest of the house.
It is a structural job. The walls and the foundation have to carry the extra weight, and that has to be calculated before anything else. At Boers & Breuer Totaalbouw we arrange the structural calculation, the permit and the complete build, including electrics, plumbing and finishing, with our own team. Joeri Boers is your contact throughout, in English.
We build roof extensions in Eindhoven, Veldhoven, Den Bosch, Tilburg, Breda and Helmond.
One point of contact
Joeri guides your renovation from the first visit to the handover.
Transparent pricing
A clear quote up front, the price agreed in writing. No surprises afterwards.
Clear planning
One project at a time, tightly planned. Handover date agreed before we start.
Building, electrics & installation
Every trade under one roof. No loose subcontractors.
How we build your roof extension
The structure comes first. Then everything goes fast, because the house is only open for a short time.
1
Visit & structural check
Joeri looks at the walls, floors, foundation and the existing roof. A structural engineer calculates whether the house can carry the new floor, and what needs reinforcing if not.
2
Design, permit & quote
We draw the new floor with you, apply for the permit and send an itemised quote in English with the price and the planning agreed in writing.
3
Build & weathertight
Scaffolding, the roof opened or removed, the new structure placed, and the house closed again as quickly as possible. We plan this around the weather forecast.
4
Stairs, installations & finish
Staircase, electrics, heating, a bathroom if you want one, insulation, plasterboard and floors. We hand over a finished floor, not a shell.
What our clients say
Most of our reviews are written in Dutch. Your browser can translate them in one click.
Recent work by our team
A roof extension on a farmhouse in Waspik and other structural work by our team.
Roof extension, Waspik
A new roof structure and an extra floor on a farmhouse, built by our own team.
Home extension
A spacious extension, from foundation and structure to the complete interior finish.
Full renovation, Waalwijk
Complete finish of a villa: herringbone floor, open kitchen and sliding doors to the garden.
Which roof extension suits your house?
Four common variants. The existing roof and the structure below decide which one is possible.
Full floor on a flat roof
A new storey across the full width of a house with a flat roof. Usually two bedrooms, or one large room with a bathroom.
Roof off, new floor on
The pitched roof comes off, a full storey goes on, and a new roof on top of that. The biggest intervention, with the biggest result.
Floor with bedroom and bathroom
A complete sleeping floor with its own bathroom. Extra pipework, a drain with the right fall to the soil pipe, and a heavier floor structure.
What does a roof extension cost?
Guide prices for a complete roof extension, including structural work, the new floor, roof, frames, insulation, staircase, electrics and interior finish. The structural calculation and the permit application are part of the process.
On top of an existing extension
12 to 18 m² extra above the extension. First we check whether its foundation and walls can carry it.
Fully finished
€40,000 to €70,000
Full floor on a flat roof
25 to 40 m² extra across the whole width. Usually two bedrooms, or one large room with a bathroom.
Fully finished
€70,000 to €125,000
Roof off, new floor on
The existing roof comes off and a full storey with a new roof goes on. The heaviest job, with the most space.
Fully finished
€95,000 to €160,000
Floor with bedroom and bathroom
A complete sleeping floor with its own bathroom, extra pipework and a heavier floor.
Fully finished
€95,000 to €150,000
| On an extension | On a flat roof | Roof off, floor on | With bathroom | |
|---|---|---|---|---|
| Guide price | €40,000 to €70,000 | €70,000 to €125,000 | €95,000 to €160,000 | €95,000 to €150,000 |
| Extra floor area | 12 to 18 m² | 25 to 40 m² | 30 to 45 m² | 25 to 40 m² |
| Duration | 6 to 10 weeks | 10 to 16 weeks | 14 to 22 weeks | 12 to 18 weeks |
| House open to the weather | A few days | About one week | One to two weeks | About one week |
| Permit | Yes | Yes | Yes | Yes |
Why the calculation comes before the design
A new floor weighs tens of tonnes, and all of it goes down through your existing walls into the foundation. In many Dutch houses from the 1960s and 1970s the inner walls are light and the foundation was never designed for a third storey. That does not mean a roof extension is impossible, but it does mean the structural engineer has the first word, not the architect. We start there, so the design never has to be redone.
- Structural calculation of walls, floors and foundation before the design is final
- Steel or timber structure chosen for weight and span
- Weather planning: the house is open for as few days as possible
- Sound insulation between the floors, so the new bedrooms are quiet
- Fire safety and escape route checked against the building regulations
- Staircase that meets the rules for a new stair, with enough headroom
Rules for your roof extension
A roof extension always needs a permit. This is what the municipality looks at.
Always a permit
Unlike many extensions and rear dormers, a roof extension always needs an omgevingsvergunning. The municipality checks the height against the zoning plan and how the new floor fits the street. We prepare the drawings and the application.
Neighbours and daylight
A higher house takes light from the neighbours. In terraced streets, municipalities often want a roof extension to follow a set pattern, so the street stays consistent. We check what has already been approved in your street.
Building regulations for new floors
A new floor is built to current rules: insulation values, ventilation, fire safety, stair dimensions and headroom. Those rules apply to the new part even if the rest of the house is old.
Where a roof extension goes wrong
Four mistakes that cost a lot of money, and how we avoid them.
1
Design first, calculation later
A beautiful drawing that the structure cannot carry means starting over, or unexpected steel and foundation work halfway through. The structural check has to come first.
2
The house open for too long
Every extra day the roof is off is a risk of rain damage. A good planning has materials on site and the crew ready, so the house is weathertight again within days, not weeks.
3
Forgetting the stairs
A new floor needs a proper staircase, and that takes space on the floor below. Plan where it goes before the rest of the design is fixed.
4
No sound insulation between floors
A light timber floor without acoustic insulation means you hear every step upstairs. We build in sound insulation as standard, especially above bedrooms.
Roof extensions across Brabant
Where we see the most potential, and what to watch for.
Eindhoven
Flat-roofed houses from the 1960s and 1970s in Woensel and Tongelre are good candidates for a full extra floor. In Philipsdorp and near the old centres, heritage rules limit what is possible. More about Eindhoven.
Veldhoven
Family homes where the attic is too small for a proper room and a dormer is not enough. Often the most cost-effective way to add two bedrooms. More about Veldhoven.
Den Bosch
Terraced houses in Maaspoort and Rosmalen where the street already has roof extensions, which makes the permit easier. More about Den Bosch.
Tilburg
1970s and 1980s homes in the Reeshof and Tilburg Noord with flat or low-pitched roofs. More about Tilburg.
Breda
Houses in the Haagse Beemden and around Princenhage where a floor on top of an existing extension adds a master bedroom. More about Breda.
Helmond
Houses from the 1970s in Brouwhuis and Rijpelberg with flat roofs that suit an extra floor. More about Helmond.
Often combined with this
Work that goes well together with a roof extension.
Frequently asked questions about roof extension
Answers to the questions we are asked most, in plain English.
A floor on top of an existing extension costs €40,000 to €70,000. A full floor on a flat roof runs from €70,000 to €125,000. Removing a pitched roof and building a full storey with a new roof costs €95,000 to €160,000, and a floor with a bedroom and bathroom €95,000 to €150,000. Structural work, roof, frames, insulation, stairs, electrics and finishing are included.
Yes, always. The municipality checks the height against the zoning plan and how the new floor fits the street. We prepare the drawings and the structural calculation and submit the application. A decision usually takes about eight weeks.
Not every house, but more than people think. The walls and foundation have to carry the extra weight. A structural engineer calculates that first, and often reinforcement makes it possible where it first looked impossible.
On top of an extension 6 to 10 weeks, a full floor on a flat roof 10 to 16 weeks, roof off and a new floor 14 to 22 weeks. The permit comes on top of that. The house itself is only open to the weather for a short part of that time.
Usually yes. The work happens on top of the house, and the floors below stay usable. There are a few noisy days and the moment the new stairs are connected. We tell you in advance when those are.
A dormer gives you standing height on one side of the attic. A roof extension gives you a complete extra floor with full height everywhere. It costs more and always needs a permit, but it adds far more space.
Usually a timber frame structure, because it is light and quick to build. Where the span or the load requires it, we add steel. The structural engineer decides, based on your house.
Yes. The main question is where the drain can go, because it needs a steady fall to the existing soil pipe. We plan the bathroom position together with the structure, so the drain and the floor work together.
It has to meet current building regulations, which are much stricter than when most houses were built. Often the new floor is the best insulated part of the house.
With a floor on a flat roof, nothing, because there is no attic. With the roof off, the attic disappears and becomes a full storey. Anything you store there has to move out before we start.
Yes, across Noord-Brabant, including Eindhoven, Veldhoven, Best, Nuenen, Helmond, Den Bosch, Tilburg and Breda, from our base in Waalwijk.
Often yes, especially in Brabant, where a house with one extra bedroom costs a lot more to buy and the transfer tax, notary and moving costs come on top. Our guide dormer, roof extension or home extension helps you compare.
Good to know about a roof extension
A roof extension is the biggest structural change most homeowners ever make, and it is also one of the most effective. For €70,000 to €125,000 you typically add 25 to 40 square metres of full-height living space on a flat roof. Removing a pitched roof and building a new storey costs more, but gives you a floor with no sloping ceilings at all.
The structural calculation decides everything. Walls and foundation carry the extra weight, and in many houses from the 1960s and 1970s some reinforcement is needed. That is why we start with the engineer, not with the drawing. After that, the priority is speed on the roof: the house is open to the weather for as few days as possible.
We build roof extensions for English-speaking clients in Eindhoven, Veldhoven, Best, Nuenen, Helmond, Den Bosch, Tilburg and Breda. You will see the Dutch word dakopbouw on your quote and permit. More Dutch terms are explained in our renovation terms guide.
Ready for your roof extension?
Book a no-obligation visit. Joeri looks at the structure of your house, tells you honestly whether an extra floor is possible and what it will roughly cost, in English.
✓ Joeri contacts you personally to talk through your plans
✓ A no-obligation visit at your home
✓ Honest advice, in English, no sales talk