Southampton City Council

You are here:home > Environment > Building control > What do I need permission For?

What do I need permission For?

Key Online Services
Submit an application online
  • Build an extension to my house? Yes, but a porch or conservatory built at ground level and under 30m2 in floor area is exempt provided that it complies with the safety glazing requirements of the Building Regulations (Part N).
  • Convert my loft into a room? Yes. This will ensure, for example, that the structural strength of the floor is acceptable, that there is safe escape from fire, and the stability of the structure is sufficient.
  • Convert garage into a habitable room? Yes.
  • Make internal alterations? Yes, it is likely the building regulations will apply if the building work will involve alterations to the structure of the building, or will affect fire precautions and access facilities for disabled people.
  • Install cavity insulation? Yes. This is defined in the Building Regulations as `building work`. The regulations will be applied so as to ensure that the insulation used is safe and suitable for the wall construction. If you use an approved installer they will generally submit a Building Notice on your behalf.
  • Construct a detached garage? No, providing the building is under 30m 2 in floor area, single storey, does not contain any sleeping accommodation, and it is built substantially of non-combustible material or when built it is no less than 1m from the boundary of the property.
  • Build a carport? No, as long as it is open at least two sides and under 30m2 it is exempt from the Building Regulations.
  • Build a covered yard/way to my house? No, provided the floor area is under 30m2.
  • Construct a porch or a conservatory? No, providing the floor area is under 30m2 and the glazing conforms to Part N of the Building Regulations. An Exemption Certificate can be applied for by contacting the Building Control Section. A porch or conservatory not separated from the existing house will require consent and an application should be made.
  • Install replacement windows/doors? Yes, if you are replacing the whole of the fixed frame and opening parts. No, if the work amounts to no more than replacing broken glass, replacing fogged double-glazing units, etc.
  • Make repairs to my house? No, if the repairs are minor. Yes, if the repair work is more significant, i.e. removing and rebuilding a wall, or underpinning a building.
  • Convert my house into flats? Yes, this is defined as `material change of use` and the whole or part of the building must comply.
  • Carry out underpinning to my house? Yes, this is specified as a structural alteration. The Building Regulations are to ensure the underpinning will stabilise the movement of the building.
  • Construct a boundary wall? No, this is not covered by the Building Regulations, but you should make sure the work is constructed safely.
  • Install fittings & appliances? Yes, if the fittings to be installed, such as WC, shower, and kitchen sink, include alterations to the drainage stack or an underground drain.
    No, if the work only involves installing additional fittings or fittings in the same location providing it does not include extensions to the drainage pipework.
  • Install/reposition heating appliances? All Gas Appliances: Yes, but if a CORGI registered installer is employed, you will not need to involve the Building Control Service.
    Solid Fuel Appliances: Yes, but if a HETAS registered installer is employed to install the appliance in a building not more than 3-storeys, you will not need to involve the Building Control Service.
    Oil Appliances: Yes, but if the building is not more than 3-storeys and an OFTEC registered installer is employed, you will not need to involve the Building Control Service.
  • Replace underground drains? Yes, unless the work would constitute a minor repair.
  • Do I need to provide disabled access? New buildings - Requirements apply to newly erected and reconstructed buildings. Extensions - extensions to dwellings are excluded from Part M.
    Alterations - no obligation to improve access, however access should not be reduced.
  • Build other small, detached buildings on my land? No, providing the building/s is no more than 30m2, single storey, contains no sleeping accommodation and is built of non-combustible material.
  • Re-roof my house? Yes, replacement roof tiles will often add considerable weight to the existing roof, which may require strengthening.

Contact information

If you want to contact us regarding the content of this page please contact us at:

For any other council related enquiries please contact: