A garage door as a system — from larch to Douglas
Why larch was not the option, how several specialist suppliers sharpened the material choice, and what is now being built in the workshop.
Somewhere between the first sketches and the arrival of the timber, a design shifts from idea to object. For this project that moment is concrete: Douglas fir has been delivered by Houthandel Bunnik, the sections are in the workshop and the dimensions match the drawings. That it became Douglas and not larch was not self-evident.
Larch was the starting point
The project began with European larch (Larix decidua) as the material. For exterior joinery, larch is a proven choice: dense-grained, tough, durable with good detailing — with the option to weather untreated or to finish, depending on the desired appearance and maintenance level. The quiet silvery weathering is familiar from old shutters and exterior doors across the Netherlands and Belgium.
But larch in the right sections proved almost impossible to source in the Netherlands. Heavy stock profiles — 75 × 150 mm for the frame, 100 × 100 and 120 × 120 mm for stiles and rails — are not standard stock here. Delivery times of weeks, inconsistent import quality, no rift-sawn sections in the required dimensions. The theoretically better choice turned out to be practically unworkable.
Around the specialist suppliers
After comparing several specialist timber yards, the picture became clearer. Each supplier contributed something to the material choice or the construction:
- Houthandel Bunnik (Leusden) offered Douglas fir in exactly the required stock sections — rift-sawn, air-dried. The most direct and buildable route. Bunnik also supplied the 18 × 135 mm featheredge KD for the cladding.
- HouthandelOnline stressed stability requirements: heavy Douglas requires precise joinery, careful gluing and clamping. A structural detail that matters in assembly.
- Van Laere flagged moisture content: kiln-dried interior timber absorbs moisture outdoors and can swell. The choice of air-dried (AD) over KD interior is deliberate — and depends on correctly detailed framing with ventilation.
- Van Gelder offered a bespoke machining route with rebating and profiling — available as an alternative for components that cannot be achieved from stock sections.
The system
The door is 2390 × 2135 mm — developed from a concrete existing situation. The bespoke system is designed around available stock profiles, so each component can eventually be replaced individually without a bespoke order. The leaf is a layer build-up: Douglas featheredge cladding on the outside, approx. 50–53 mm PIR insulation, 9 mm birch plywood inner skin. Total leaf depth approx. 80 mm. Glass, rebates and seals are confirmed through production preparation and a trial detail.
Douglas: durable with good detailing
Douglas fir (Pseudotsuga menziesii, FSC/PEFC) weathers evenly with correct detailing: sufficient overhang, drainage and ventilation around the frame. The choice between untreated weathering, oiling or finishing remains open — depending on the desired appearance and maintenance level. A deliberate choice, not a default.
First realisation
The first realisation is now underway. The system is being assembled in the workshop as a working reference project, validating material choice, glazing build-up, hardware, sealing and assembly in practice. Drawings and documentation are fully developed to assembly level.
Parametric design as a production advantage
The proportions of glazing, stiles, rails and cladding are worked out parametrically. The system can therefore be adapted quickly to different widths, heights, timber sections and glazing layouts — without rebuilding the design from scratch. Each configuration generates updated drawings, cut lists and order schedules directly.
Bespoke for comparable situations
The system can be adapted to existing openings, facade rhythm, preferred timber species, glazing layout, insulation value and hardware. It applies to garage openings, workshops, outbuildings, studios and renovations where daylight, thermal performance and crafted finish come together.
Do you have an existing opening that needs a bespoke door? Studio Bartholomeus can adapt the system to your dimensions, material, insulation and finish. Get in touch.