Frequently asked questions

Window insulation ratings are based on the U-value. With modern windows, the U-value ranges from 0.7-1.0. The value mostly depends on the type and size of the window and the components of the insulated glazing. The smaller the U-value, the better the insulation properties. The U-value (Uw) of a window shows how many watts of heat escapes the room per one squaremetre of window surface if the outside temperature is 1 degree below the temperature indoors.

In spring and summer, strong solar radiation can cause indoor temperatures to rapidly rise. If you want to maintain a lower temperature, use sun protection glazing. These usually include a special surface coat. Selective glazing with sun protection ensures good insulation (low U-value) and keeps excess solar energy from entering the room.

Sun protection is expressed with the g-value or SF-value. The bigger the g-value, the strong the so-called greenhouse effect. The smaller the g-value, the more stable the room temperature.

The noise reduction property of glass is measured through the noise reduction index value Rw or Rw+Ctr value expressed in decibels (dB). The bigger the value, the better the noise reduction properties of glass. Buildings adjacent to high traffic streets, railways, airports or motorways should use noise reduction windows. The following factors are important when it comes to the noise reduction properties of windows:

  • for double frame windows, the architrave should be as wide as possible, keeping the two fames at a maximum distance
  • glass panes should be of a different thickness and also as thick as possible: glazing comprising panes of different thickness and an asymmetrical construction improve sound insulation
  • lamination of glass: glass used two or more layers of glass. From a noise reduction standpoint the best strategy is to use a noise reduction film.

LT shows what percentage (%) of visible light is transmitted through the glass.

Safe glazing is either toughened or laminated glass. This glass does not generate sharp shards upon breaking and for this reason it is used for large windows and windows and balcony doors starting from the floor.

Air vents help ensure functioning ventilation in your home by keeping indoor air fresh and healthy. The vents are designed to mix outdoor air with the warm indoor air in the upper part on the room, thereby avoiding draught. Read more HERE.

Due to thermal stress, glass may be at greater risk of breaking in steam rooms. This is why we recommend using toughened glass with suitable finishing in saunas.

It all depends on the size and type of the window and what insulated glazing is used. There are a number of different options. Contact our sales team and we will find a solution that works for you!

A thermal break, i.e. thermal stress may occur when the temperature differences in different points of the glass exceeds a certain limit. Thermal breaking depends on the type and quality of glass. Thermal stress usually starts at a 90-degree angle to the edges of the glass and is followed by a winding crack.

What ever finish you like. Take a closer look at what we have to offer HERE

A German type window has a single frame and opens inwards (tilt and turn). This is the window that is used most often in new buildings and public buildings in Estonia. See more HERE

A Finnish type window is a double frame window that you turn to open inwards. This type is used most often when the objective is to ensure excellent noise reduction inside the room. See more  HERE 

To prepare an initial quotation, the client should provide us with the technical specifications of the windows. If there is no such data, hand-drawn sketches will do. See HERE to read more about what you should focus on before ordering windows and balcony doors.

Yes, Fenestra windows and balcony doors have a 2-year warranty regardless of the person installing the windows. The warranty does not cover issues arising from incorrect installation.

For standard solutions, the production process is 4-5 weeks and can start from the moment all data (incl. those collected during measurement) are finalised. With special solutions you should take into account that production may take longer. In addition, delivery may also be longer in spring and summer (up to 8 weeks). To make sure windows and doors are ready by a specific time, we recommend making an advance booking for the time allowed for delivery.

By adding a CE marking on construction products, the manufacturer confirms that the product meets the requirements of any appropriate EU directives. Products with CE marking have been tested in accordance with European standards to ensure that all manufacturers are subject to equal requirements and conditions.

Certificates by test labs assure clients that the product has the properties promised. According to the product standard for windows, the manufacturer is required to disclose the product’s resistance to wind load, imperviousness to precipitation, permeability to air and thermal insulation classes.