Make the most of the square metres you already have. An attic conversion is the most cost-efficient way to create extra living space. We produce the permit-ready drawing from €1,195, ready in 4 weeks, for any municipality in the Netherlands.
An attic conversion turns an unused attic into a full bedroom, study or bathroom by making use of existing floor area. An internal renovation without roof alterations is often permit-free. The permit-ready drawing costs from €1,195 and is ready in 4 weeks or express in 1-2 weeks. Drawing services across the Netherlands.
An attic conversion makes use of the space that is already there. No foundation work, but skilled craftsmanship is still required: floor structure, insulation, headroom and installations all need to be right. These are the elements we map out.
Roof plane insulation is mandatory when converting to habitable space. We specify the Rc value and build-up (cavity or sarking), so your contractor knows immediately what is required.
Existing floor joists are designed for storage loads (100-150 kg/m²); a habitable room requires at least 175 kg/m². We check whether additional joists or a steel flat bar are needed.
The knee wall closes off the triangular section and forms the sloped wall finish. Its position and height determine how much usable rectangular space you retain.
A habitable room requires a light opening of at least 10% of the floor area. A roof light is internal (often permit-free); a dormer or ridge raising for standing height requires a permit.
A habitable room requires a fixed staircase (no loft ladder). In addition a fire safety requirement applies: a second escape route via a roof window or dormer may be mandatory.
A bathroom requires pipework and mechanical ventilation. A bedroom requires at least heat recovery ventilation or controlled ventilation. We indicate the installation spaces in the drawing.
Four questions, about 30 seconds. No obligation.
An internal attic conversion without any changes to the roof is permit-free in most cases. We produce the permit-ready drawing that complies with the Building Decree. From €1.195. Request a no-obligation quote for your exact situation.
Indicative calculator. The drawing is a fixed price; the construction you commission separately through a contractor.
* Build costs are indicative, based on approximately €1,200 per m² for internal finishing. Demolition, foundations or roofwork are not included. Request a quote for the exact drawing costs.
From a simple internal bedroom to a full suite with dormer. We advise on what is feasible in your home.
Interior renovation only: floor, insulation, staircase and roof window. No changes to the roof itself. Most affordable option, often permit-free.
When the attic height is too low, a rear dormer provides the required 2.60 m headroom. A building permit is required for the dormer itself.
A complete master suite with bedroom, bathroom, walk-in wardrobe and private access. Requires a wide dormer or ridge raising plus structural calculation for the wet area.
An attic conversion makes use of existing space, making it the most cost-efficient way to add usable living area. Here is how it compares to a dormer and a roof extension.
The permit requirement depends heavily on exactly what you do to the roof and the property. An overview of common situations.
Example project · internal · permit-free · +18 m² living area
Challenge: A family in Amersfoort used their attic only for storage. They wanted a proper bedroom for their eldest child but did not know whether the floor was strong enough and how much light was required for a habitable room.
Our approach: We calculated the existing beam structure. It proved sufficient for a bedroom without additional reinforcement. We drew a roof window on the rear roof slope to meet the daylighting requirement and designed the escape route via the window in accordance with the Building Decree. No permit required: purely internal, with no alteration to the roof itself.
Result: 18 m² of extra living space added, a light and fully functional bedroom. Drawing in 4 weeks; the renovation itself took 3 weeks with the contractor.
An attic conversion is the most efficient way to add living space. What you still need to know.
No changes to the roof, no alteration to the load-bearing structure and not a listed building: in most cases an internal attic conversion is permit-free. We verify this in the drawing and provide written confirmation.
SOURCE · BBL / ENVIRONMENT ACT 2026A converted attic adds directly usable living space. Estate agents typically calculate +€1,500 to €2,500 per extra m² of living area in the WOZ value for a well-executed attic conversion.
SOURCE · NVM HOUSING MARKET FIGURES 2025An attic conversion increases the property value and can be co-financed in a renovation mortgage (up to 106% of the post-renovation value). We provide the drawing your bank or valuer needs.
BRON · NHG.NL 2026Not always. A purely internal attic conversion, where the roof is not altered, is often permit-free. As soon as you add a dormer, a roof window (larger than the permit-free size), or a ridge raising for extra headroom, a building permit is required. A permit is also always required for a listed building. We check your situation free of charge.
A permit-ready attic drawing costs from €1,195 (excl. VAT). The exact price depends on the attic area, the intended use (bedroom, bathroom or suite) and whether a dormer or ridge raising is included. The construction costs themselves (by a contractor) average between €15,000 and €35,000, depending on the level of finish.
That depends on the existing floor joists. A storage attic often has a floor load capacity of 100-150 kg/m², while a habitable room requires at least 175 kg/m² (NEN 6702). If in doubt, we include a structural calculation in the commission so you know exactly what needs to be reinforced.
According to the Building Decree, a habitable room must have a minimum clear height of 2.60 m over at least 50% of the floor area. For daylight, a minimum window opening of 10% of the floor area applies. If that height is not achieved, a dormer or ridge raising is the solution and we arrange that drawing alongside.
We deliver the drawing within 4 weeks. Express delivery is possible in 1-2 weeks. If a building permit is required (for a dormer, larger roof window or listed building), allow for an 8-week municipal decision period on top of the drawing period.
Yes. We draw attic conversions across the Netherlands from our office in Amsterdam. The drawings are done entirely remotely; any required permit is submitted to your municipality. For every municipality we know or verify the building regulations.
A fixed-price quote within 1 working day. Free check on whether your attic conversion is permit-free. No obligation.