All OCPs are prepared under the authority of the Local Government Act (LGA). The LGA describes an OCP as a comprehensive guiding document, primarily in relation to land use planning. The LGA outlines required policy components (e.g. approximate location, amount and type of residential development to meet the community's expected housing needs for the next five years) and optional components (e.g. policies relating to social well-being in the community). Historically, New Westminster has chosen to include a wide range of optional policy areas in the OCP, including social, cultural, economic and environmental policies, where a local government can influence community success and livability.

The LGA states that a local government is not obligated to immediately meet the objectives of the OCP or to undertake any project included in the plan, or to retroactively amend existing bylaws. However, all of the City's subsequent policies, plans, capital projects or bylaws must conform to the adopted OCP. For example, the Zoning Bylaw and the Subdivision and Development Bylaw should be made consistent with the OCP over time.