The Standard Building Control Follows

Most homeowners walk into their first building control meeting expecting a judgment call. The BCO will look around, decide if it feels right, and tick a box. That's not what happens. Building control is compliance against a published statutory framework. The standard is a single Act of Parliament, a single statutory instrument made under it, and a published library of official guidance documents you can read for yourself this afternoon.

Every Part. Every reference. Where each one bites in your build and which document the BCO has open on their tablet when they arrive on site.

Yes, There Is a Standard

The legal duty sits in the Building Regulations 2010, statutory instrument SI 2010/2214, made under the Building Act 1984. The Act gives the Secretary of State the power to make regulations. The 2010 regulations are the current version of those regulations, and they have been amended several times since (most recently and most consequentially in October 2023 and April 2024).

Alongside the regulations, the government publishes the Approved Documents. There are currently 18 Approved Document Parts plus AD 7, the cross-cutting document on materials and workmanship. Each one explains how to comply with the corresponding requirement in the regulations. A homeowner's umbrella reference, the Manual to the Building Regulations, ties the system together and is the right place to start before opening any individual document.

SI 2010/2214

The statutory instrument number for the Building Regulations 2010. If you ever need to cite the law itself, this is the reference. The Approved Documents are guidance under it, not the law.

The Three Layers

This is the part that catches most homeowners out, and it's the single piece of knowledge that changes how you read every BCO interaction afterward.

The standard has three layers, not one.

Layer 1 is the law. The Building Regulations 2010 set out the legal requirements. Schedule 1 of the regulations contains the substantive requirements, lettered A through T. Each requirement is a short, abstract statement of what the building must achieve. Part A says the building shall be designed and constructed so the loads applied to it are sustained and transmitted safely. Part L says reasonable provision shall be made for the conservation of fuel and power. They don't tell you how. They tell you what.

Layer 2 is the guidance. The Approved Documents take each requirement and explain one accepted way to meet it. Approved Document A gives span tables, beam sizes, and bearing dimensions. Approved Document L gives U-values, airtightness targets, and SAP calculation methods. If your build follows the relevant Approved Document, building control treats that as compliance. That's the legal magic of an Approved Document: it creates a presumption of compliance without being a rule you must follow. You can deviate from it, provided you can demonstrate compliance with the underlying regulation by another route.

Layer 3 is the technical detail. The Approved Documents do not carry the precise numbers for everything. They cite British Standards (BS), European Norms (BS EN), and industry standards like NHBC chapters. Approved Document A points at the Eurocodes (BS EN 1990 series) for structural design. Approved Document P points at BS 7671 for electrical wiring. Approved Document G points at BS EN 806 and BS 8558 for water installations. When a structural engineer designs a beam, they're not reading AD A. They're reading the Eurocodes. AD A is the route map that tells you which standard applies.

So when the BCO turns up and points at "Part L", they're pointing at Layer 1 (the legal duty). They're checking against Layer 2 (the matching Approved Document) as the default route. And if you've deviated from Layer 2, they're going to want Layer 3 calculations on the table to prove the deviation still meets the regulation.