Comparing House Sizes

Since 1988 SI, or metric units, have been the sole legal units of measurement in Australia.

However many builders and real estate agents still quote property in squares, which is an Imperial measurement. Are they trying to confuse you or just slow to change?

Conversion

Basically one square is 100 square feet, for example; a square with sides of 10 feet in length. In metric that is 9.3 square metres so make sure that you don’t confuse a square with 10 square metres. One square metre is usually written as 1m2 and is equivalent to 10.75square feet or 0.1075 of a square.

Points to Remember

You also need to bear in mind is what is included in the dimensions quoted for example:

• Some people will quote the overall plan area which means that it includes the volume of the external walls which are typically 0.25m thick. That can mean a figure between 10 and 20m2 (that’s up to 2 squares) is external walls which is unusable space.
• Some will quote the area under the roof which if you have full eaves can amount to another 20 to 40m2
• If you are looking at a 2 storey house the documents will probably be based on doubling the ground floor area even though the stairs and stair void lose livable floor area.
• Some include the garage and others don’t.

I have also heard of qualifications in sale offer documents saying variations in dimensions of up to 10% are acceptable. How often would you think that you would get a bigger house?

The best advice I can give if you are comparing plans is to measure the plans yourself rather than relying on quoted documents and when it gets down to signing a contract check that the dimensions on the contract document match your original understanding.

Have you had any problems with comparing sizes?