To get a price, you can type in how many square metres of cladding you need. It's very easy to work out.

We're going to work out the total area of one side of a building, then subtract the windows and doors, then add 10% extra for wastage.

1) For each wall that you’re cladding, measure the full width and the height in metres to work out the total area.

In this (expertly designed) example, the frontage is 9 metres wide and 4.7 metres high. 9 x 4.7 gives a total 42.3 square metres.

Total area of frontage = 9 * 4.7 = 42.3 square metres

2) Work out the area of the doors and windows

In this house front there are four windows and a door. Measure the width and height of each window and door, then add the areas together:

• Window 1: 1.9 x 1.2m = 2.28 square metres
• Window 2: 1.2 x 1.2m = 1.44 square metres
• Window 3: 1.2 x 1.2m = 1.44 square metres
• Window 4: 1.9 x 1.2m = 2.28 square metres
• Door: 1.0m x 2.0m = 2.00 square metres

Total area of windows and doors = 9.44 square metres

3) Subtract the area of the doors and windows from the total area of the wall.

We now have our total area (42.3 square metres) and the total area of the doors and the windows (9.44 square metres). Because we don't want cladding to cover the windows and door, we take the door and window area away from the total area.

Total area to clad = 42.3 – 9.44 = 32.86 square metres to clad

4) Add at least 10% spare for wastage

We recommend ordering at LEAST 10% more cladding than you've measured for to account for the required cutting and shaping.

32.86 square metres + 10% = 36.146 square metres. In this case, we'd round it up to 37 square metres.

Total to order = 37 square metres

Do the same for any other sides of the building, add them together and you'll have your grand total.