I need to get a bit of clarification about a roof im doing at the moment.

My architect has specced a set of roof beams very early on in my plans, but from what I know and what people have said when ive been pricing the steel seams a little large for the job...........................so,

Can anyone work out what size of beams I should be using?

the roof area is 86m2 and the building is 10m x 8m

the steel sizes ive been given to use are 203 x 133 x 30 @ 10m lengths x 3.

I'll try and give a few answers to what people will ask.

a, no i dont want wooden trusses of any sort.
b, I know over spec is great for strength but i would like to ensure im using the correct size for the job, as over size = over cost !
c, I cannot get hold of the architect, and have been unable to for 3 weeks now
d, the roof will be covered in Marley Modern concrete roof tiles.

Cheers all
Mark