Selection of a house design is one of the most time-consuming steps in the entire house construction process. There are several thousand ready-made designs available; there is also a possibility to create an individual design. Most of us, build a house for life, so this step requires us to go ahead and plan the future in order to live comfortably.

This is the moment when many key issues need to be carefully analysed, starting with the size, number and layout of rooms, ending with functionality and visual issues. An important issue that affects design cost estimate and functionality of a house are windows. This is the element we will focus on in this section. We will analyse step-by-step issues related to windows, which are worth taking into account in this process.

Size and number of windows

When selecting a house design, we should pay special attention to size and number of windows. Failure to do so may make us choose a solution that does not meet our needs or it will have a strong impact on our budget.

We often believe that the more windows the more expensive it will always be. This is not necessarily the case as the cost of a bricked up window opening, including building materials with insulation, plastering and labour can be comparable to the cost of a medium-class window. Price of window joinery consists of many factors and with simpler solutions the window does not have to be an element which will significantly increase the cost of construction; specifically if we manage to find small windows with classic shapes.

If you dream about large glazing, you have to consider cost increase, so it is worth to re-calculate the final cost of a solution during project selection.

Designers often draw visualization of a house and plan large window constructions, e.g. 3-metre high, two-sashed windows. It is not recommended to make such tilt and turn windows, because sash itself is very large and heavy element that is uncomfortable to operate. Then a good solution may be to divide the window into more sashes or reduce it.

Large and expensive HST structures can be replaced by other solutions, e.g. by selecting a balcony with a low double sill, where only a single part will be opened. Should the windows be smaller that 3-meter high, application of a tilt and slide solution may be considered.

If you opt for a design including windows from 3-metre high upwards, you should then consider installation of a more expensive HST solution, as only this one will ensure that such a structure is suitable for use.

Moreover, when selecting a design involving large glazing, we must be aware of the role played by heat transfer coefficients. When dreaming about very large and panoramic glazing, it is worth investing in very good parameters related to thermal transmittance (thermal transmittance should be as low as possible).

Usually windows are regarded as a location for heat loss, but it must be noted that they can be a source of passive solar heating in winter. Here, however, certain standards for passive buildings must be met.

Corner windows and non-standard shapes

Corner windows make up a solution that is gaining in popularity, especially in modern structures.

Corner windows provide better access to a lot of sunlight and emphasize modern nature of a building. Application of such a solution allows to obtain a unique visual effect. We can achieve the result of opening the house to the garden or terrace.

Such windows undoubtedly have a lot of advantages, but before selecting a design that offers such a solution it is worth considering few issues. It is necessary to plan them already at the house design step, because there is a need to implement dedicated solutions such as lintel preparation or ceiling reinforcement.

At this stage it is recommended to consider application of window covers, as not all types of roller shutters can be installed in case of corner windows.  We have to abandon top-mounted roller shutters as the boxes are located inside an apartment and these would overlap.  An alternative option is installation of incorporated roller shutters, but we must make a proper decision at the construction stage.

Non-standard window shapes make an important contribution to the design. Each arch, triangle and trapezoid makes a much higher cost of window joinery; it is estimated that a non-standard window is 60-70% more expensive than a square or a rectangle one.

Windows vs. the cardinal directions

Not everyone realizes that location of a house in relation to directions of the world makes it one of the key factors that we should take into account when planning layout and size of windows.

Southern exposure of windows will be associated with natural insulation of rooms. Living in such a setting should be looked for by those who seek a lot of sunlight in the early afternoon.

Eastern exposure will be ideal for kitchen, as the morning sun is not so strong and the kitchen keeps a lot of heat from cooking.

Anyone who likes to sleep longer should invest in blinds or place a bedroom to the south or north side of the apartment.

South-western exposure is a good selection for a living room; the sun would look inside it for most of the day, but without excessive temperature rise.

Windows facing north will mean much less natural light.

Functions of the premises

While reviewing house designs, it is also worthwhile to look at dedicated applications related to room's functions.

If a bathroom on the ground floor have been designed in close proximity to a busy street or neighbouring buildings, installation of ornamental glass or Venetian mirror panes, which allow avoiding roller blinds, is worth considering.

In the kitchen, on the other hand, windows with sliding fittings, instead of standard ones, work well. Such application allows the window to be opened by moving it sideways and allows the area near the window to be used freely.

Families with children are recommended to familiarize with the range of safe glass. In this case, tempered glass is a good solution. In case of breakage, toughened glass breaks down into small pieces with edges. Another solution is to use laminated glass. Such glass breaks on impact, but pieces of it remain in place. This is due to combining the glass panes with one or more intermediate layers.

Another solution which is worth considering in case of large glazing is self-cleaning glass that is covered with a special coating. Its cleaning can be carried out due to a technology that employs sunlight and rainfall. UV rays break down the dirt and rainwater removes it. Care of such windows is much easier.

Hidden hinges in windows make also an interesting concept. Windows with hidden hinges not only look better, but they are also much easier to keep clean, as dust has no space to settle.