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Building control – frequently asked questions

Find the answers to commonly asked building control questions.

Do I need building control for installing replacement windows?

Yes. With effect from April 2002, all replacement glazing came within the scope of the Building Regulations. Any replacement windows or doors will have to comply with strict thermal performance standards to reduce energy loss, essential if we are to meet increasingly stringent national and global energy saving targets.

When the time comes to sell your property, your purchaser’s surveyors will ask for evidence that any replacement glazing installed after April 2002 complies with the new building regulations. Compliance can either come from Building Control by submitting an application or employing a properly registered contractor who can self-certify their own work. See current competent persons schemes to find a registered contactor.

Do I need building control for repairs to my house?

Generally – no. Repairs of a minor nature where you are replacing like-for-like do not usually need approval. This includes, re-pointing, and replacing a small area of brickwork.

However you will need approval if the repair consists of removing a major part of a wall and rebuilding it. In the case of re-roofing, if the new tiling or roofing material is heavier or lighter than the existing materials, an approval under building regulations is required.

Major renovation work can also require an application where it involves the renovation of a thermal element such as roof, external walls or floors, where more than 25 per cent of the ‘element’ is affected. This can affect a variety of works such as re-roofing, re-rendering, re-plastering, re-flooring etc.

Building regulations now require that the insulation within these elements is upgraded as part of the renovation works to meet new standards. The requirements can be fairly complex so we recommend you contact us to discuss your particular project.

Do I need building control for internal alterations within my house?

Yes, if the alterations are of a structural nature such as the removal or part removal of a load-bearing wall (for example, a wall, partition, joist, beam or chimney breast). You also need approval if, in altering a house, work is necessary to maintain the means of escape in case of fire.

Do I need building control for installing sanitary fittings?

If you want to install or alter the position of a WC or bath, you will need an inspection. If the fittings are replaced in the same location using existing waste pipes, you don't need to obtain approval. 

Do I need building control for installing heating appliances?

If you are planning to install or alter the position of a heating appliance, you will need an inspection:

  • gas, solid fuel or oil heating: you will need an inspection unless the work is carried out by a properly registered installer.
  • hot water storage heating: you will need an inspection if the system is unvented (under direct mains pressure)
  • see current competent persons schemes to find a registered installer.

Do I need building control for carrying out electrical works such as installing or replacing electric wiring?

Yes, if the works consist of one of the following:

  • all work that involves adding a new circuit to a dwelling
  • extra low voltage lighting installations, other than pre-assembled, CE-marked lighting sets
  • electric floor or ceiling heating systems
  • solar photovoltaic power supply systems
  • small scale generators such as MicroCHP (combined heat and power) units
  • garden lighting or power installations
  • extension to the electrical system (separate circuit) to small detached buildings such as sheds.

and you are carrying out works to one of the following:

  • dwellings
  • common parts of a building serving one or more dwellings (excluding power supply to lifts)
  • buildings that receive electricity from a source located within or shared from a dwelling
  • gardens or in land associated with a building where the electricity is from a source located within or shared with a dwelling.

In addition you will need approval for the following work in a kitchen or locations containing a bath tub, shower basin, swimming/paddling pool or hot air sauna:

  • adding lighting points (light fittings and switches) to an existing circuit in a special location
  • adding socket-outlets and fused spurs to an existing ring or radial circuit
  • installing or upgrading main or supplementary equipotential bonding (earth bonding).

Can my neighbours object to what is proposed in my building control application?

No. There is no requirement in the building regulations for you to consult your neighbours, but it would be courteous to do so. Objections can be raised under other legislation, particularly if your proposal is subject to approval under the Town and Country Planning Acts.

What happens if I do work without approval?

Local authorities have to ensure that building work complies with the building regulations. If the work does not comply, we may instruct you to alter or remove it. If you fail to do this, we may serve a legal notice requiring you to do so. The Council may also prosecute as a last resort.

If you have already completed work without approval it is possible to gain retrospective approval by making a regularisation application.

You will need to provide all the necessary information and where requested ‘invasive investigations’ may be needed to enable the surveyor to assess whether the building complies (eg: removal of floors/ceilings or exposure of foundations).

Are there penalties for contravening building regulations?

Yes. If you contravene the regulations by building without notifying the local authority or by carrying out work which does not comply, the local authority can commence proceedings which may lead to an unlimited fine and a criminal record.

Do I need to construct a granny annex as a separate dwelling?

If it is attached to the main dwelling and connected via an internal interconnecting door, the proposed annexe will be treated as part of the main dwelling.

If on the other hand it is self contained and not connected via an internal door, it will be treated as a separate dwelling. This will have implications for fire separation and sound proofing between the dwellings.

Please contact us to discuss your particular project to see how the regulations will affect you.

How do I find a reliable builder or contractor?

Contact the relevant trade association to ask for a list of members in your area. Many trade associations have protection schemes and will help to resolve disputes.

You can try these external websites to find a reliable builder or contractor:


If you experience problems with the services of your contractor or supplier, you can seek advice from Citizens Advice Consumer Advice service on 08454 04 05 06.

Need more help to find answers?

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