Building control inspection process

You must give us notice when your building work reaches a certain stage so we can inspect it to make sure you have complied with building regulations. There are several stages of inspection.

Commencement (statutory)

When you start the building work, we will discuss the project and remind you about approval conditions and check that your site is as shown, especially drain layout and depths.

Foundation excavation

We check that the ground is strong enough to hold the building, and:

  • how close and deep drains and manholes are
  • for signs of filled ground or limited areas
  • how deep the foundation is
  • how close trees are
  • if any trees have been removed

Ground made of clay must be at least 1000mm deep

Foundation concrete

We don’t inspect concrete in the ground. All blockwork should be damp-proof level and we will inspect the work before backfilling.


We inspect the way you prepare the area underneath the floor before you add concrete or cover (known as the oversite). For example:

  • hardcore - hard non- absorbing materials for filling such as broken bricks, stone or concrete
  • damp-proof membrane (DPM) – material to prevent moisture being transmitted such as polyethylene sheeting laid under a concrete slab
  • floor insulation laid tightly under beam and floors


We will inspect the damp-proof course (DPC) to make sure the materials are suitable and wide enough to prevent water rising from the ground into the property.

Concrete fillings must be at least 225mm below DPC level.

 You may also add some walling above DPC level to ensure external wall construction is correct.

Laying of drains

Submit a request before you backfill the drains.

We will look at how you laid drains in the property including:

  • material suitability
  • drains’ fall and line
  • material for bed and border
  • access points

Floor joists

We will check the size, grade, centre, bearings, lateral restraint straps and herringbone strutting or noggins of joists.

Roof timbers

We will check the size, grade and centre bracing, lateral restraint and wall plate straps of the roof timbers.

Ask us to inspect the property before adding the felt and battens.

Test on drains

Please arrange an appointment for us carry out a drains test on your property. Make sure the property is ready when we call.

Occupation (Statutory)

Let us know if someone is staying in the property before you complete the work.

Completion (Statutory)

We will check these items when you complete the building work:

  • Fire precautions and requirements (even for a small extension)
  • Ventilation to rooms and roof voids
  • Waste
  • Roof coverings and insulation
  • Staircase
  • Safety glazing

Completion certificate

We will give you a completion certificate when you finish the work. It confirms your work complies with building regulations. Keep the certificate in a safe place as you will need it if you want to sell the property. 

Failure to obtain a completion certificate could jeopardise your sale of the property.