How to calculate roof area.

[JamesAsus]

As many times as ive tried to calculate roof area im still confused.

Its a lean to gable end roof which buts up against the 2nd story wall of my house.

Is it literally a case of measuring the length of it and multiplying that with the rise?

For example the length from the front of the house is 2.7 metres. The rise from the front of the roof is about 1 metre.

So that would put the total area at 2.7 Metre Squared?

Or do i have to times this figure by 2? I see some calculations saying to times by 2?

Its like the below diagram, so ive measured the rise and length and multiplied them together?

 

[noseall]

As many times as ive tried to calculate roof area im still confused.

What are you trying to work out? The area of the tile coverage or roof volume?

 

[JamesAsus]

What are you trying to work out? The area of the tile coverage or roof volume?

Roof area mate.

NHBC say roof areas less than 3m squared dont need ventilation, im trying to work out if my roof fits within this.

Its 2.7 metres wide and the rise from the lowest to highest point is a metre, and its lean to style like the diagram above.

 

[Dereekoo]

Assuming the roof sticks out 2.7m the tiled area is 2.9m2 per meter length of roof (pythagoras and all that)