Standard door and window sizes
When you are recording a house that exists, you measure. When you are designing one, you need sizes that are known to work — and that a joiner can actually supply. These are the ones in ordinary use.
Doors
Almost every internal door in a house is the same height. What changes is the width, and it changes with what has to get through the opening.
| Door | Width | Height | Metric (approx) |
|---|---|---|---|
| Main entrance | 3'-0" | 6'-8" | 900 × 2030 mm |
| Bedroom / living | 2'-8" | 6'-8" | 800 × 2030 mm |
| Kitchen | 2'-8" | 6'-8" | 800 × 2030 mm |
| Bathroom / WC | 2'-4" – 2'-6" | 6'-8" | 700 – 750 mm |
| Store / utility | 2'-0" – 2'-4" | 6'-8" | 600 – 700 mm |
| Double / French | 5'-0" – 6'-0" | 6'-8" | 1500 – 1800 mm |
A quoted door size is the leaf, not the hole. The structural opening has to be bigger to take the frame and the fixing tolerance — usually 2 to 3 inches wider and 1 to 2 inches taller than the leaf. Plans are dimensioned to the structural opening, so say which one your figure is.
Widths that matter for access
If a wheelchair has to pass, a 2'-8" leaf is the practical minimum and 3'-0" is better, because the clear width is smaller than the leaf once the door is open and the stop is in the way. The same is true of a bed or a fridge: measure the appliance, not the doorway.
Windows
Window sizes are far more variable than doors, because they answer to the room rather than to a person walking through. The figures below are common starting points.
| Room | Width × height | Sill above floor |
|---|---|---|
| Living / bedroom | 4'-0" × 4'-0" | 3'-0" |
| Large living | 6'-0" × 4'-6" | 2'-6" |
| Kitchen, over a counter | 4'-0" × 3'-0" | 3'-6" |
| Bathroom | 2'-0" × 2'-0" | 5'-0" |
| Stair or corridor | 2'-6" × 4'-0" | 3'-0" |
How much window a room needs
Many building regulations set the glazed area as a fraction of the floor area — often around a tenth for daylight, with a smaller openable fraction for ventilation. A 12 ft × 12 ft bedroom at one tenth wants roughly 14 sq ft of glass, which a single 4'-0" × 4'-0" window does not quite meet. Check the rule that applies where you are building rather than assuming; it varies between countries and between local authorities.
Showing them on the plan
An opening on a drawing needs three things to be buildable:
- A position. Dimension from the nearest corner to the jamb, or to the centre line — one or the other, consistently.
- A size. Width and height, and for a window the sill height as well, since it never appears in plan.
- A mark. Doors are marked D1, D2 and so on, windows W1, W2, and every opening of the same type shares a mark. The marks then tie to a schedule listing the size, the quantity and the type.
The schedule is what a joiner prices from, which is why two windows of the same size must carry the same mark — otherwise the quantities are wrong.
DrawHousePlan does the schedule for you. Drop a door or a window into a wall at the size you want and it is marked automatically, openings of the same size share a mark, and the printed sheet set includes a door and window schedule with sizes, sill heights and quantities. The defaults are the standard sizes above, so you can draw first and adjust later.
A note on local practice
These are the sizes in common use in imperial-measured construction, which covers most house building in Sri Lanka, India and the United States. Metric markets work to different rounded sizes — a 762 mm or 838 mm door leaf in the UK, 820 mm in much of Europe — so if you are buying doors locally, ask the supplier for their stock sizes before you fix the openings on the drawing. It is much cheaper to design to a stock size than to order specials.