Construction law is a general reference to various areas of law as applied to the design, engineering, and construction of buildings—including residential buildings and commercial buildings—as well as bridges, roads, pipelines, railroads, water transmission and distribution systems, electrical power transmission systems, sewerage systems, and other structures.

In addition to the law governing the filing and removal of mechanic’s and materialmen’s liens (also known as contractor liens), construction law includes contract law, employment law, personal injury law, insurance law, zoning law, and real estate law.

In Washington State, construction law encompasses a wide range of legal areas as they relate to the construction industry. This includes the creation and enforcement of construction contracts, which detail the rights and obligations of parties involved in construction projects. Washington follows specific statutes regarding mechanic's and materialmen's liens, which are legal claims made by contractors and suppliers for payment for work performed or materials provided. These liens must be filed and removed in accordance with state law, particularly under the Revised Code of Washington (RCW) Title 60. Employment law aspects cover worker safety, labor disputes, and wage requirements, including compliance with the Washington State Prevailing Wage on Public Works Act. Personal injury law addresses accidents and injuries on construction sites, while insurance law deals with the types of coverage required for construction projects. Zoning and land use regulations, governed by local ordinances and state statutes, affect where and how structures can be built. Real estate law also plays a significant role, dealing with the purchase, sale, and development of property. All these areas are integral to the legal framework that governs construction in Washington State.