Washington Cost Plus Residential Design-Build Contract is a type of construction contract used in the state of Washington. This type of contract is a combination of design and construction services provided by one contractor. Under this contract, the contractor is paid the actual cost of the materials and labor used in the project plus an additional fee for managing the project. The contractor is responsible for the design and construction of the project, and the homeowner is responsible for the cost of the project. There are two types of Washington Cost Plus Residential Design-Build Contract: 1. The Standard Cost Plus Contract — This contract provides the contractor with a fixed fee for design and construction services. This fee is determined based on the estimated cost of the project. 2. The Negotiated Cost Plus Contract — This contract allows the contractor to negotiate the fee for design and construction services. This fee is based on the estimated cost of the project as well as the contractor’s experience and expertise. Both types of contracts provide the homeowner with the ability to control costs while ensuring the quality of the project.