Registered Building Control Approvers (RBCA), formally known as Approved Inspectors, are private sector companies who have been approved by government and the Building Safety Regulator (BSR) to provide building control services. Registered Building Control Approvers are governed by the Building Act 1984, the Building regulations and government issued procedural guidance. As a result the general format of building control services is the same for Registered Building Control Approvers and Local Authority Building Control.

Registered Building Control Approvers functions are primarily governed by the Building Act 1984 and Building regulations 2010, The Building (Registered Building Control Approvers etc.) (England) Regulations 2024. This legal framework was indroduced in 2024 as as result of the Hacket review by Dame Judith Hacket following the Grenfell Tower tragedy. Prior to this a RBCA was known as an Approved Inspector, which were first developed in the 1984 Building Act, and the first approved inspector to be approved and registered was the NHBC in 1985. Since 1997 the regulations were further developed and additional Approved Inspectors were registered. Today, Registered Building Control Approvers have replaced Approved Inspectors legally speaking, but many companies like BCS remain the same trusted company who have sucessfully registered under the new legal framework.

Local Authority Building Control functions are primarily governed by the Building Act and the Building Regulations.

Registered Building Control Approvers and private sector building control as a whole is ever changing. This is mainly driven by the desire of Registered Building Control Approvers to provide a high level of professional service and ensuring compliance, whilst maintaining a practical and reasonable approach.