Suppose you lived in a box! A box the size of your house. A box without windows, and only one door. There’s no daylight, no fresh air and no views. Electric lamps are the only light source, an air exchanger provides ventilation, and four walls are the only scenery. Could you live in such a box? Probably not!

Windows have an immense effect on our everyday comfort and contribute much to the atmosphere of a room. Whether building a new house, or remodelling an old one, the window treatment is an important design consideration for function and aesthetics. The size, shape and placement of windows has a major impact on both exterior and interior design.

On the exterior, the style and proportion of windows affects the overall look of a house. The style of windows should conform to the character of the house. Proportion relates to the ratio of the height to the width of a window, and pane sizes. Older houses tended to have taller proportioned windows, and smaller pane sizes due to the limited technology of the time.

Improvements in glass technology have increased window sizes. Glass can now span much greater distances than in the past, and even stretch from floor to ceiling if desired. When selecting replacement windows for an older house try to be as true as possible to the original materials, sizes and shapes to maintain the integrity of the style period. Many manufacturers are sensitive to this market and can supply windows with suitable design features, but with the latest technical advantages such as insulating glass, low emissivity coating and an argon gas filled cavity.

On the interior, the primary function of windows is to provide natural light. Many of our activities revolve around daylight. The level of daylight tells us when to get up, when to go to work, when it is suppertime, and when to go to bed.

In the design of a new house, consider the layout in relation to solar orientation. An ideal lot faces south. On the south side locate the living areas, thereby taking advantage of sunlight when these rooms are usually occupied. On the north side locate rooms which require little or no daylight, such as storage rooms. Bedrooms are mainly used at night and are best located on the north side. Bedroom windows need not be overly large, but local building codes require a minimum opening area for fire escape.

Consider the function of each room. How are windows best placed to provide daylight where it is needed most? Work areas such as kitchens and laundry rooms need high light levels. Consider the depth of a room. If a room is deep in relation to the exterior wall, use taller windows which cast light farther into the space.

What type of light is preferred at mealtimes? Do you like the bright morning sun at breakfast, or a dwindling sunset at supper? The deliberate placement of the kitchen or dining room in relation to the sun’s path is quite possible in the layout of a new house.

With modern, air-tight houses a breath of fresh air is often welcome. Think about the areas which require good ventilation. Bathrooms immediately come to mind, but kitchens, family rooms and living rooms require good air quality too. Consider fresh air needs when locating operable windows.

Views give us a sense of place and a connection with the outdoors. A good rule of thumb for the main living areas is to be able to see something near, something at middle distance, and something far. For the less used areas of the house try to get two of the three types of views if possible.

With window design consider all the variables before making the final selection. Think of the exterior effect you want to create. Look at each room regarding daylight, ventilation and views. Avoid choosing one type of window and then using it everywhere. There’s little or no cost difference in selecting the right windows versus the wrong ones. Make sure your windows suit the aesthetics and the function.

INSULATING GLASS

Windows lose much more heat than an equivalent area of insulated wall. Insulating glass reduces the heat loss and conserves energy. Insulating glass is a combination of two panes with a sealed air space in between, and is also called a “sealed unit”.

The sealed air space prevents direct contact of indoor air with outdoor air, and reduces the coefficient of heat transmission, or U-value of the window. Sealed units also reduce condensation. Insulating glass comes in an array of standard shapes and sizes, and can be customized to suit imaginative designs.

Insulating glass is available with a low emissivity, or Low-E, coating. This thin transparent film is installed on the sealed side of the glass and acts as a thermal mirror. Heat is reflected back into the house on the inside, and harmful rays from the sun are blocked on the outside. The air space in a sealed unit can also be filled with argon gas to further reduce heat transmission.