Site Inspections

1. Commencement

Before work commences on site you should inform the Building Control Service that work is about to begin. It may be necessary or desirable to have a site meeting at this stage to discuss the project and work through any possible problems that may not be apparent from just a check of the plans alone.

 

Once the foundations for the proposed building have been excavated it is essential that prior to concrete being placed the Council be invited to inspect the works to date. At this stage Building Control will consider the depth of excavation in relation to strata type, location of trees, proximity of drains or wells and adjacent buildings or basements.

After the foundations for your building are concreted an inspection of the completed Foundations must be made. We will be looking to ensure that the concrete is of sufficient depth and quality to allow the safe transfer of load from the new Building to the Ground.

 

4. Damp Proof Course

When the Damp Proof Course (D.P.C.) is laid on a solid or cavity wall it will need to be inspected to ensure that it will fulfill its function in preventing rising damp in the buildings fabric. In general a D.P.C. should be positioned 150mm above external ground level and be linked with all abutting D.P.C.s and the Damp Proof Membrane (D.P.M.).

 

5. Over-site Inspection

When the over-site (floor) preparation is ready to pour the concrete, notice should be given to the Building Control provider, to enable it to be inspected before the floor slab is cast. The over-site preparation should include well compacted and blinded hardcore together with a 1200 gauge damp proof membrane (Or 1000 gauge if to the P.I.F.A standard).

The membrane is usually continuous with the dpc. Variations of the membrane position may be necessary. e.g. radon proof barrier. Insulation will usually be required, which may go above or below the concrete slab. Depending upon the design, steel reinforcement may also be necessary.

Other forms of ground floor construction will also need to be inspected before they are covered over.

 

6. Drains before backfilling

All laid drains be they for Foul or Rainwater must be inspected before they are covered over. This is to ensure that adequate falls accessibility and capacity is provided and that the drains are provided with adequate protection once covered. A test of the drainage to ensure a watertight system may be undertaken at this stage and again at the completion stage

 

7. Drains before backfilling (testing)

When the drainage has been covered a supervised test to ensure a watertight system should be undertaken and again at the completion stage.

 

Though not a stage of construction requiring statutory notification, most surveyors will wish to carry out an interim site visit often referred to as a pre-plaster inspection, or sometimes simply as a roof inspection. The exact timing of this visit will vary depending on the nature of the project and the requirements of the surveyor in question, so it is advisable to check with your Building Control department to establish when this should occur.

This can be a valuable opportunity to both review the work that has been carried out up to that point, perhaps identifying any problems while they are still relatively easy to rectify, and to discuss the future works necessary to progress the works through to a successful completion.

Listed below are some of the areas that may be discussed at this stage, along with some of the more common pitfalls. This list is based on a typical new dwelling, and is not exhaustive since no two projects are the same. It will however give some useful pointers.

Roof structure: In the case of a prefabricated truss roof, checks will be made on the verticality and spacing of the trusses, the quantity and positioning of timber roof bracing and the installation of metal gable and wall-plate restraint straps. Manufacturers design calculations will be requested for the trusses if not already provided. In the case of a traditional cut roof, the survey will also address the sizes of the timbers used, and the general workmanship of connections, notches and joints.

The method of providing ventilation to the roof space may be discussed, which can be achieved through installation of proprietary eaves ventilators (along with ridge vents if sloping ceilings are planned), or may be provided through the use of a vapour permeable roofing felt. In the case of the former, the relationship between airflow and roof insulation should be considered. If the latter is proposed, then it must be exactly as per the manufacturers certified details, which may include counter-battening or other measures which would not otherwise be considered necessary.

First floor joists: The size of the joists in relation to the span will be checked, as will the installation of structural noggins and wall restraint straps where required. Where they bear onto external walls, the joists should either be on hangers, or built in via proprietary sealing units.

Insulation (type and thickness in relation to the required U-values) may be inspected or discussed at this stage. Insulation to the roof and to sections of sloping ceiling may already be in place. In the case of timber frame structures, the insulation and vapour barrier to external walls may also be viewed prior to plasterboarding. Remember that walls and floors abutting unheated spaces (eg. garages and loftspaces) must achieve the same thermal values as if they were external elements.

For acoustic purposes, some form of insulation may also be required to the majority of internal floors and hollow partitions. If you are building more than one attached dwelling, far more rigorous standards will apply to the separating wall/floor elements, and you should consult carefully from the start with your Building Control Department as well as your appointed designer.

Stairs and Balustrades: If the stairs have been installed at this stage, then checks will be made, to include the following: The pitch of the stairs (which should be less than 42 degrees), the size of landings, including any restrictions imposed by doors which swing onto them, the height of balustrades (generally 900mm to internal stairs/landings) and the spacing of balusters (no more than 99mm).

Doors to the Ground Floor: The main entrance door should provide a clear opening of at least 775mm wide. The minimum width for internal doors will range from 750mm to 800mm, depending on their relationship to the hallway or corridor off which they open. Remember that clear opening widths must allow for the thickness of the door itself, and so a 750mm door will not provide a clear opening of 750mm.

Wall sockets and switches should all be mounted within a zone of 450 – 1200mm from the finished floor.

A ground floor WC is required, to a size and layout which complies with the guidance in Approved Document M, and this will normally be far enough advanced to verify at this stage. An outward opening door will almost certainly be a requirement.

Windows and Doors: the glazing specification will be checked to ensure that it complies thermally (a u-value of 2.0 or under for timber or plastic windows, or 2.2 for metal windows) and that safety glass has been used where necessary (within 800mm of the floor, or 1500mm in the case of glazed doors/glazing to either side of doors). Windows which are required to provide escape in the event of a fire may also be checked at this stage to confirm that they provide a large enough clear opening – a minimum of 0.33M2 and no less than 450mm in width or height, with the bottom of the opening falling between 800 and 1100mm of the floor. (escape windows are required primarily to bedrooms, but can be called for in other rooms depending on circumstances). Finally, the provision of background ventilation to all rooms, most commonly achieved through the inclusion of vents in the heads of the windows, can also be seen at this point.

Electrical Installation: Electrical works that are not being installed by a contractor under the government’s ‘competent persons’ scheme will require inspecting at this stage.

If the installation is being carried out by a contractor under the ‘competent persons’ scheme an inspection at this stage is also a useful way of checking that the other requirements of the Building Regulations are being met.

In any case the surveyor will normally remind the contractor at this stage that a copy of the commissioning certificate will be required at completion. Failure to provide a suitable certificate will result in the completion certificate being held back.

Future works often discussed during this visit may include the following:

Requirements for extract ventilation to kitchens, utility rooms and bathrooms. Fans provided to windowless rooms should operate with the light switch, and operate on a timed over-run.

The provision of smoke detectors, which must be mains operated, inter linked and backed up with a battery. At least one per storey will be required, but sometimes more depending on the size and layout of the dwelling.

Proposals for a ramped or level access to the property, leading to an accessible threshold (with no steps greater than 14mm).

Thickness and type of any insulation still to be installed.

Lengths and diameters of internal waste & sanitary pipework.

Fire Protection of the Structure – Any structural elements which form part of, or give support to a floor in a dwelling are required to be fire resistant for a minimum period of 30 minutes. This may include walls, steel or timber beams and timber floor joists. Methods of protection could be by cladding/lining (eg. plasterboard), applying intumescent paint treatments and, in the case of some timber structural elements, over-sizing to ensure they will remain structurally sound for the required period even when burning. In the case of plasterboard ceiling linings, which tends to be the most common solution, consider the measures necessary where penetrations occur to the ceiling (eg. where inset spotlight fittings are cut into the ceiling).

Fire separation of fire risk areas – most commonly an integral or attached garage, which must be separated from the dwelling by 30 minute fire-resisting construction complete with self-closing fire doors if access is to be provided between the garage and the house.

Position and type of central heating boiler, especially the flue terminal, in relation to any opening windows, doors or vents. The provision of ventilation to any open flue appliances (including open fireplaces and wood burners) may also be discussed. Gas boilers should be of the condensing variety unless proven to be unreasonable to be installed.

Positioning, where relevant, of LPG or oil storage tanks. The level of fire risk to the building or any boundary will be relevant, as will the possibility of polluting watercourses in the case of oil tanks.

Paperwork which may be required for completion, eg. outstanding structural calculations, SAP ratings etc.

9. Occupied before completion (where applicable)

This inspection is carried out if the new building is to be occupied before it can be considered complete for the purposes of the Building Regulations.

 

10. Work Completed

This inspection is carried out as the name suggests when all work is completed. Most aspects of the construction are gone over a second time to ensure the building works are satisfactory. A drains test for example may be undertaken on any new drainage installed. If the work is found to be satisfactory and all other relevant inspections have been made a Completion Certificate for the work will be issued.

MOST HOUSE SALES WILL REQUIRE A COMPLETION CERTIFICATE FOR ANY WORKS UNDERTAKEN THAT HAVE REQUIRED BUILDING REGULATIONS APPROVAL.

In the case of non-domestic work, staged completions may be required. For example, completion of all works relating to fire precautions and means of escape.

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