Building Regulations

Building Regulations- a guide for your home extension

What are Building Regulations?building regulations

The building regulations control the construction of a building but are generally less concerned with its appearance and layout (other than some critical aspects such as means of escape in the event of a fire). They were originally intended to primarily control health and safety but have been extended to aspects such as energy conservation and disabled access. This section covers their form in England, different rules occur in Scotland, Northern Ireland and Wales.
Since 1985 the regulations have been in the form where the basic regulations are fairly brief but these are supported by approved documents which give in a more detailed and technical manner ways of complying with the requirements. In theory this allows a greater flexibility in complying with the basic legal requirement by other means (perhaps new materials or methods) or arguing that the normal approved document recommendations are too onerous in a particular situation. Mostly these are issued by the Communities and Local Government Department and downloadable from In practice it is not essential to be familiar with all the documents, which can run to many hundreds of pages, many of which will not apply to a modest extension.
  • Most building work other than minor repairs and refurbishment require building regulation approval, examples of the type of work that might need approval include:• Structural alterations, perhaps removing a supporting wall or a new opening in a wall.
  • Removal of structure that may have a significance in protecting against fire such as perhaps the walls around the stairs of a three storey house (even if not load bearing).
  • New bathroom (but not just replacing existing sanitary ware), new boiler, rewiring, replacement windows etc.There are a number of exemptions for extension type buildings:
  • Conservatories under 30m² floor area and at ground floor level, which should in general have a translucent type of roof (e.g. glass or polycarbonate) and the low level glazing should comply with the normal safety glass requirements (if it did not comply then the exemption would not apply so it would be necessary to make a building regulation application which would almost certainly be refused because the glazing was not acceptable!). The doors and/or windows between the conservatory and main house should be retained and if replaced should be double glazed to external standards.
  • Porches up to 30m ² floor area. Carports, covered ways etc. open on at last 2 sides up to 30m ² floor area.
  • Detached single storey buildings not used for sleeping accommodation of up to 30m ² floor area but if it is within 1 metre of the boundary should largely be non-combustible material such as brick and slate externally. For smaller buildings up to 15m ² floor area any construction can be used even within 1 metre of the boundary.
Even where the main building work is exempt some aspects such as the electrical installation may need to comply. See Town Planning and see Other Legal Requirements .

Obtaining Building Regulations Approval

There are basically two main approaches to obtaining approval either full plans or building notice.
Full Plans

  • Plans are prepared and submitted to the council’s Building Control Department with the necessary forms, any other supporting documentation such as calculations and the councils’ fees. Individual councils set their own fees although they are broadly similar amounts
  • The fee is usually paid in two parts, an initial amount when the application is submitted and the remainder when work commences although particularly with smaller amounts they may be combined and paid at the beginning. There are some exemptions such as works for the benefit of a disabled person.
  • Plans are then examined, quite often a letter will be sent raising some queries and eventually a decision is made to approve or refuse the application. 
  • The examination and decision is carried out by Building Control officers and would not generally be referred to council committees or seek the opinion of neighbours as it is basically a technical exercise judged against the requirements of the regulations, not taking into account aspects such as appearance or overlooking. 
  • The approval can sometimes be conditional, either adding some additional requirements that may have been omitted or asking for additional information (structural calculations etc.) to be provided at some future date.
  • It is possible to commence the works before a decision is made provided the required 48 hours notice is given; however, it has the disadvantage of not having an agreed scheme to work to.
  • When the work commences the Building Inspector will make inspections, there are some that are particularly important such as foundations, drains, damp proof course (dpc) etc. but they may choose to inspect other aspects as well on a regular basis.
Building Notice:
  • Under this procedure only minimal information is provided to the council at the beginning; usually a form, a small scale site plan and the council’s fee. (This can sometimes be higher than the combined plan submission and site inspection fees under the full plans procedure).
  • In practice the council might for example require structural calculations which in turn could require an accurate plan for an engineer to assess the loads and the council to check. None the less in a number of straightforward cases it can save on the necessity of detailed plans but it is best suited to minor works such as drainage alterations etc. rather than major building works.
  • Building Notice does require the builder to be very familiar with the regulations and acceptable forms of construction as he will not be working to approved plans.
  • Site inspections will be made in the same way as the Full Plans procedure although in practice they may need to be longer or more frequent in order to clarify what has been done or needs to be done to comply with the regulations.
Self Certification
With legislation increasingly covering aspects of building work that were traditionally not controlled by the building regulations such as electrical work and replacement windows it potentially became more difficult to rely on building inspectors to inspect all aspects and so some organisations were permitted to allow their members to self certify their work. This usually involves their members going through some initial checking of their competency plus some on going inspection of samples of their work, they in turn certify that a job has been completed to the required standard and inform the council. Examples of this process are FENSA (for windows), Gas Safe (for gas boilers), NICEIC (for electrical work) together with a number of other regulators. The procedure is perhaps of more use for isolated work on the main property rather than an extension. There is probably little benefit whether the windows are installed in an extension by a FENSA registered contractor – provided they are done properly and to the required standard, as this aspect of the work will be inspected as part of the extension by the building control officer in any event.
Completion Certificate:
Provided the works have been assessed as having complied with the building regulations then a Completion Certificate will be issued. This may or may not coincide with completion in terms of a builder’s contract, for example it will not generally be necessary to fully decorate internally to comply unless required for fire or weather resisting criteria. Some clients may choose to do some aspects of the works such as fitting out a bathroom themselves; this might delay the building control officer from issuing a Completion Certificate on the main construction carried out by the builder. A Completion Certificate should be kept with other documentation for a property and will often be required when a property is sold.
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