What a real specification looks like

Material brands, U-values, fire ratings, beam sizes, ironmongery. If the quote says 'as drawing' without a written spec, you are guessing what you will get.

Provisional sums

Allowances for items not yet specified — kitchens, bathrooms, finishes. Reasonable in some categories, abused in others. Pin them down where you can.

Comparing quotes

Line by line. If one builder includes scaffold and another excludes it, the totals are not comparable until you adjust for the difference.