An Architect wil probably use this meeting to get information and develop a brief. For example:
Size / shape / layout of house?
1 / 2 storey / dormer? (Planning dependant)
Sizes & number of rooms (bedrooms, recreational, utiluty, etc)
Storage
Heating - oil / gas / underfloor / solar etc
Finishes - internal and external
General finishes - floors, walls, etc
Kitchen - shape, layout, finishes
WC's
Most importantly, agree a scheme, establish your budget and stick to it. Get an architect to schedule out all major items of expenditure, so you can see where your money is going.
Further meetings will then develop this information into drawings for a planning application. Try and have every thing buttoned down before going to a builder - try to avoid changes during the build, these will be more expensive.