In England, structural alterations such as removing a load-bearing wall, forming a new opening, or installing beams for an extension or loft conversion are building work under the Building Regulations. That means the work needs to be approved and inspected - either by your local authority building control or by a registered building control approver.
Structural design (Approved Document A)
A structural engineer designs the steel and provides calculations showing the beam, its bearings and any padstones or posts are adequate. Building control reviews these, and inspects the work on site - typically when the steel is installed and before it is covered up.
Fire protection (Approved Document B)
Steel loses strength in a fire, so beams supporting floors or walls usually need fire protection. In many houses, 30 minutes' fire resistance is required, commonly achieved by boxing the steel in fire-rated plasterboard. Where the steel is to remain visible, an intumescent coating can be used instead. Building control will confirm what is needed for your property.
The Party Wall etc. Act 1996
If a new beam bears into a wall shared with a neighbour, or you cut into a party wall, you will usually need to serve a party wall notice before work starts. This is separate from building regulations and planning.
Planning permission
Planning permission is a separate question about what a building looks like and how it is used. Many internal structural changes don't need planning permission but still need building regulations approval. Extensions and loft conversions may need planning or fall under permitted development - check with your local authority or designer.
Who does what
- Structural engineer: designs the steel and produces calculations
- Building control: approves the design and inspects the work
- Steel fabricator: fabricates and supplies (and can install) the steel to the engineer's design
- Builder: temporary propping, padstones, installation if not by the fabricator, and making good
This guide is general information for projects in England, not legal advice. Always confirm requirements with your building control body and designer.