Window Room Size Ratio

As a general rule keep the total glass area of a house using ordinary windows between 20 30 of the total floor area.

Window room size ratio. We measure the total area of the window to be fitted vertically and horizontally to calculate the area of the window. 1 a given room must have a window or glass door that is sized to equal at least ten percent of the floor area of the room. Larger is better not only to make escape easier but also to allow firefighters packing tools and breathing equipment to enter the area quickly. The proportion of windows to outside wall space will depend on your home s style and location as well as your personal preferences.

Minimum window size is set by your local code. Adding a window to a room will change the proportion of windows on your home when viewed from the outside. There are also as stated egress requirements. If you know the right proportion you can determine the size of your windows to maintain that ratio.

This is the wall to window ratio of the building. This is called the glass to floor area ratio or the window to floor ratio and it applies for most standard window installations in extensions. How many windows do i need. It s 15 of the floor area here.

You can read more about it in document l1b on the uk government planning portal. Ideal window size based on floor area for standard clear glazing. The curtain will hang 3 inches below the bottom of the window sill. At a minimum the bottom of the window must be no more than 44 inches from the floor and that the actual opening be a minimum of 20 inches wide and 24 inches high.

In temperate climates higher levels of exposed thermal mass will enable greater areas of windows. As a general guide the total window area should be less than 25 per cent of the total floor area of the house. Divide the number of the total exterior wall area by the total area of all the window openings in the building. Be it a ground floor extension or loft conversion the general rule we advise for effective daylighting is that a room s glazing should be equivalent to 15 20 of the whole floorspace at a minimum to ensure daylight hits the whole area.

So if a room is 10 feet wide x 12 feet long then the room area would be 120 square feet and the minimum size of the window in that room would have to be12 square feet. We divide that by the total floor area in the room.