A window is an important architectural detail of whatever building. The flow of light into the room, ventilation, possibility to look outside and a certain aesthetic value make window selection an important designer’s task.

Windows can be classified by various properties.


Wood. Wood was the first and is still a popular material to make window frames of. Wooden windows are warm, good-looking, available in a great variety of sizes and designs, can create a comfortable indoor ambient without hothouse effect. However, they are rather expensive, care-demanding, need waterproofing, pest proofing, mould- and rot-proofing.

Plastic. Plastic windows are easy to care, user-friendly, durable, available in different colours and shapes. However, they need scrupulous compliance with the manufacturing and installation techniques, lest overtightness would promote mould and fungi in the room.

Aluminium. These are light-weight, durable, user-friendly windows that are good-looking and affordable in terms of price. The disadvantages include low thermal insulation, therefore, aluminium windows are most often used for premises of seasonal use or where high temperature is needed permanently.

Reinforced plastic windows with reinforcing metal framing in PVC cladding.

Glass unit structure

Single glazing nowadays can hardly be seen anywhere except outbuildings and premises of seasonal use, while multiple glazing is used for residential buildings. Here a glass unit consists of two or more glass panes with an intermediate filling appropriate to render required properties. Two glass panes with a gas filled clearance in-between comprise a single chamber.

Glass units can be classified by the number of chambers as follows:

  • Single-chamber units applicable to balconies, verandas, decks, summer houses, outbuildings
  • Double-chamber units consisting of three panes and two gas filled chambers between them, generally used for residential premises
  • Three-chamber units consisting of four panes and three gas filled chambers between them. These are rare, used in environments of high noise level or extreme temperatures

Opening schemes

Dead windows can’t be open.

Hinged windows can be open either inwards or outwards, swung open in horizontal or vertical plane.

Tilt windows is a kind of hinged windows with a limited opening angle.

Tilt and turn windows combine both opening schemes.

Bi-fold windows.

Sliding windows.


Rectangular — most common





Complex — combination of elements of various shapes

Windows with special properties

Soundproof windows have a thicker outer pane and a wider clearance between the panes.

Impact-resistant windows can have hardened outer glazing, reinforcement film, outer multilayer triplex, or a combination of such features.

Energy efficient windows feature low-emission glazing with metal oxide coating intended to reflect heat rays and send them back to the room.

Tinted windows have darkened glasses (mass-coloured or coated with film).

Solar control windows feature film-coated outer glazing or special glass with UV absorbance ability.

Electrically heated windows feature a glass heating system and condensation prevention.

Electrochromic windows provide electronic adjustment of glass tint degree.

Self-cleaning windows have an extra coating with reduced adhesion to moisture and dust.

Multifunctional windows can combine several of the above properties.

Ornamental windows have various patterns made on the glass with strips or transom.

Stained glass windows consist of multi-colored elements that make up a pattern visible in the light.


Windows can be horizontal or vertical, panoramic, with one, two, three or more opening leaves.

In addition to the frames and glasses, windows include hardware of various materials and designs, can optionally be child-safe and/or burglar-proof.