You will need:
Measure all the heated rooms in your home, including hallways and landings. Don’t include unheated areas or unconverted lofts.
For stairs, measure as if there were no stairs but floor in their place at each level.
For each room, draw its outline on a piece of paper. Don’t worry about your drawing skills, it’s the measurements that need to be accurate.
If it’s a simple rectangle, measure the width and the length of the room, then multiply these together to get the room’s area.
If it’s a complex shape, then split it up into simpler shapes. Work out the area of each shape individually, then add them together to get the room’s total area.
BBC Bitesize has information on how to break up complex shapes and how to calculate the areas of triangles, parallelograms, and trapeziums.
Once you have worked out the floor area for each room, add the areas together to get the total floor area for your home.
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