Fenestrum specialises and manufactures these products:

  • Euro type window in 78mm (A energy efficiency class).
  • Euro type window in 100mm (A+ energy efficiency class.
  • Timber windows for passive houses (A++ energy efficiency class).
  • HS systems for entering the terrace.
  • Patio S systems for entering the terrace.
  • Bifold type doors for entering the terrace.
  • Timber entrance doors (available in 78mm and 100mm).
  • Sash spring windows (for the UK market).
  • Sash box windows (for the UK market).
  • Casement flush windows (for the UK market).
  • Casement stormproof windows (for the UK market).

Windows manufactured by Fenestrum can be seen in luxurious Vilnius old towns’ houses, public spaces or even churches and of course in individual houses in prestigious places in Lithuania. Fenestrum production is well appreciated by English, Russian and German architects, and real estate developers.



Fenestrum’s products are in high demand because are made of certified high-quality timber. In the process of making timber windows Fenestrum uses only ecological and coatings that are made on water basis and let timber window to “breathe”. The manufacturing process itself is ecological too because the timber sawdust is carefully collected to make a sawdust briquette from it. The final Fenestrum’s products are ecological and harmless for both human and the environment. Timber windows and doors are impregnated with water based impregnates (they changed the acrylates and alkyds, that mean became more human and environment friendly), primed coated with water-based paints and varnish. There are no harmful substances in the coatings, such as formaldehydes.



By choosing Fenestrum timber windows and doors its’ clients not only create the cosiness, luxury and warmth in their homes but also ensures effective usage of energetic resources which is no doubt especially important for the planet’s future. Being environmentally friendly Fenestrum’s timber windows also stands out for its’ high quality, aesthetics and longevity. Fenestrum timber windows and doors also has wide possibilities in design changes, are CE certified and meets all energy efficiency and sound isolation requirements.