The Building Regulations stipulates that all building work requires a building permit, unless the work is specifically exempt under schedule 3 of the regulations. A building permit is written approval from a registered building surveyor certifying that your drawings and documents comply with the Building Regulations. Apply for a building permit here.
You must have a Building Permit before any work can begin. Please note you may also need a Planning Permit for the proposed works (even where a building permit may not be required). Penalties may apply if you commence building work without the correct permits, you may also be compelled to demolish illegal buildings, so never rely on informal or verbal advice that permits are not needed.
Select a category above for a list of works that require a Building Permit.
Several items in Schedule 3 of the Building Regulations 2018 exempt work from the requirement for a building and occupancy permit if the building work will not "adversely affect the structural soundness of the building" and "will not adversely affect the safety of the public or occupiers of the building". These terms should be interpreted to apply to the construction process and the completed building. For example, even if the finished building will be structurally sound, if during construction there will be an adverse effect on any structural element or on the safety of the public or occupiers then the exemption does not apply. This means that any building work which involves work to structural or load bearing elements of an existing building, regardless of cost, will require a building permit.
Always speak to a registered building surveyor before you commence work to ensure you have the required approvals in place.