The five main types of Construction Contracts are:
Lump Sum - A lump sum is agreed upon for a project, e.g. $20,000 to remodel the kitchen.
Time & materials - The customer pays for the actual costs of time and materials.
Costs plus - This is similar to time and materials, except that it also includes a "plus" for profit.
Unit price - The project is broken up into smaller chunks, or units, rather than one overall price.
Guaranteed Maximum Price - As it sounds, there is a guaranteed maximum, and the contractor becomes responsible for any cost above that guaranteed maximum.