Timber - the classic choice

In our production, we only use top quality timber, where one of the requirements is also that it must be knot-free, thus avoiding the brown rings from the knots that eventually penetrate the paint.

Windows and doors in timber heartwood

We exclusively use timber that is at least 90% heartwood. Heartwood is naturally waterproof due to the high content of oils and resins, which also contain fungicidal substances. Heartwood timber is well suited for making windows and exterior doors. Our goal is for our windows and doors to suit all buildings and environments. So it is important to let us know if you have special requests for the design of your windows and doors. There might be more opportunities to make your dream home a reality than you think.


At STM it is possible to customise components to meet individual needs.


We have a complete window and door program, made to order and according to your measurements, using modern production methods and high-tech woodworking machines. This lets you customise windows for “odd angles” and unique buildings. 


Wood is a natural product, and like all other materials, can be degraded by wind and weather and the sun’s UV rays. Therefore the right surface treatment is of the utmost importance.


All of STM’s timber components are surface treated, cf. “2ØKO”, which is environmentally friendly, and together with STM’s solid frame/frame design, it has a long life.



We exclusively use top quality timber with a high proportion of heartwood which, due to its firmness, only absorbs 20% moisture. As the decay process first starts at 30% moisture, timber heartwood is extremely well-suited for production of windows and exterior doors.


Surface treatment:

Timber components are exclusively delivered in knot-free heartwood, which is very strong and resistant with no knots in the paint. The timber is treated with the system “2 ØKO”, and is then sanded and top coated with water-based paint in an electrostatic plant. STM uses 20-30% more paint than the danish windows industri requirement of 80 microns.


2 ØKO requirements:

The entire exterior part of the component (from the sealing outward) consists of 100% heartwood.



Our components come in 17 standard colours, but if you do not find the colour you want amongst these, you can choose special colours for a small surcharge.


See examples of model drawings here


Click on the pictures below to see product data