Maintenance and renovation work

Maintenance and renovation work

This section provides you with general information about issues that you need to consider when carrying out maintenance work to ensure that you comply with the Building Regulations (BR).

For more information, see our 'Building regulations' section.


Underpinning is a building method used to increase the depth of a building's foundations. The soil beneath the existing foundation is excavated and is replaced in phases with foundation material, normally concrete.

Underpinning requires close attention to design, methodology and safety procedures. If not carried out properly, this kind of work poses very real risks and could see damage to or collapse of the existing home.

The reasons for underpinning are generally:

  • The existing foundations of the building have moved – this is caused by poor soil or changes to the soil conditions (e.g. subsidence has occurred).
  • There has been a decision to add another storey to the building, either above or below ground level, and the depth of the existing foundations is inadequate to support the modified building or load (weight) of it.

Underpinning work requires very careful planning and execution. If you propose to underpin an existing foundation, approval will normally be required. Gaining such approval will usually involve the preparation of a structural design of the underpinning, including the process to be carried out during construction. An initial step, before substantial commencement of the work, will generally be for a trial hole to be dug next to the existing footings so that a structural engineer or surveyor can make an assessment of the circumstances.

Method and inspections

The exact method to be employed for underpinning will depend on the specific circumstances of the situation. To avoid excessively undermining the existing foundations and/or causing further damage to the structure above, the excavations for the underpinning should be carried out to the engineer's exact instructions and details.

If not carried out properly, this kind of work poses very real risks and could see damage to or collapse of the existing home. You are therefore advised to employ experienced people for the design (e.g. an experienced designer and structural engineer) and construction (e.g. somebody with experience of underpinning and general building work) of the project.

A typical method is for short sections of underpinning to be carried out individually. Depending on how much of the foundation is to be underpinned, it may be possible for more than one section to be carried out simultaneously – subject to the sections being sufficiently remote from each other.

The excavation for each section of underpinning will normally be inspected by a design engineer and a building control surveyor before it is concreted. Filling the excavation with concrete will not guarantee that the underpinning will provide sound support to the existing foundation, because of the real possibility that voids between the two will remain. Therefore, it is usually necessary for sand and cement packing to be rammed into the void to ensure the support. This may also be inspected by the engineer and building control surveyor.

The timing of each stage and the specification of the materials to be used will vary on a case by case basis and should normally be the subject of a structural engineer's design.


The BR set out overall criteria and requirements to ensure electrical safety. You should bear in mind that any electrical work you carry out within your home, garden, garage shed or other storage buildings may need to comply with the requirements of the BR. If you are unsure about whether you are required to comply, you should contact your local authority's BR Control department.

All electrical work should follow the safety standards in BS 7671 (the wiring regulations) which can be found on the British Standards Institute (BSI) website.

These rules have been introduced to help reduce the number of deaths, injuries and fires caused by faulty installations.

The BR only set standards for electrical installation work in relation to dwellings (houses, flats etc.). If the work is carried out in industrial or commercial buildings it is covered by the Electricity at Work Regulations 1989 and the Electricity at Work Regulations (Northern Ireland) 1991. The Health and Safety Executive (HSE) and the Health and Safety Executive for Northern Ireland (HSENI) are responsible for making sure that electrical installation work in these kinds of buildings is safe, and if you have any queries about work in these buildings, you should contact the HSE or HSENI if the building is located in Northern Ireland.

In England & Wales, the BR do not restrict who may carry out electrical installation work. If you want to do the work yourself, you should make sure that you know what you need to do before starting. It might be helpful to buy a good electrical installation or DIY guide to help you. In Northern Ireland, however, you should use a NICEIC registered electrician for any electrical works in order that you can be provided with an Electrical Installation Completion Certificate to submit to Building Control.

The BR do not set standards for the safety of electrical appliances, but they do require that fixed connections of appliances are safe.

Checking for safety

Where the works require a BR application, it should be checked to make sure that it is safe. This checking can be done in either of two ways: by using an electrician registered with a Competent Person Scheme or by notifying the building control section of your local authority.

For more information, see our section 'Approval for building works'.

Competent Person Schemes

In relation to electrical safety, this refers to an electrician who is registered by an organisation authorised by the Secretary of State and who is able to certify that the work carried out is safe, without you having to notify Building Control. Once works are complete, the electrician will arrange for you to receive a BR compliance certificate within 30 days of the completion of the work. Your local authority will then also be notified about the work by the electrician.

The Competent Person should also provide you with a completed Electrical Installation Certificate which shows that the work was tested for safety.

It is advisable to ask the electrician to provide information about which scheme they belong to and their membership number. You will then be able check with the organisation to make sure they are registered. Listed below are the organisations which run the Competent Person Schemes for electrical installation work:

In Northern Ireland an NICEIC registered electrician will be able to supply you with an NICEIC completion certificate in respect of the electrical installation, which you may need to provide to building control before they will sign off any works. You should contact your local authority building control department to check their requirements in this respect.

Minor works

The BR allow certain works (known as non-notifiable or minor work) to be carried out without having to notify building control or using a registered electrician. Such work includes:

  • Replacing any electrical fitting (for example, socket outlets, light fittings, control switches)
  • Adding a fused spur (which is a socket that has a fuse and a switch that is connected to an appliance e.g. heater) to an existing circuit (but not in a kitchen, bathroom or outdoors)
  • Any repair or maintenance work
  • Installing or upgrading main or supplementary equipotential bonding
  • Installing cabling at extra low voltage for signalling, cabling or communication purposes (for example, telephone cabling, cabling for fire alarm or burglar alarm systems, or heating control systems)

If you are not sure whether the work you want to undertake is notifiable, you should contact your local authority building control department for advice.

Minor electrical work can also present a risk to safety. If qualified electricians carry out the work, they should give you a Minor Works Certificate which means that they have tested the work to make sure it is safe. If you do the work yourself, you may wish to engage a qualified electrician to check it for you.

Bathroom and kitchens

Work to refit a kitchen with new units does not generally require BR approval, although drainage or electrical works that form part of the refit may require approval.

If a bathroom or kitchen is to be provided in a room where there wasn't one before, Building Control Approval is likely to be required to ensure that the room will have adequate ventilation and drainage, and meet requirements in respect of structural stability, electrical and fire safety.

Ground floor WC

Any dwelling unit that has been constructed after 1999 will have a ground floor WC installed which has been designed to cater for any visiting wheelchair users.

During any re-fitting, this WC should not be removed and the accessibility of the WC should not be made any worse as it would then be inadequate for future wheelchair users.

For these reasons, a Building Control application may be required if any alteration is to take place to an existing ground floor WC.

Floor structure

If the use of a room is changed and could result in the load (weight) on the floor structure changing significantly, work to strengthen the floor may be necessary.

Replacement of doors or windows

An external window or door is a 'controlled fitting' under the BR and certain standards must be met when such a window or door is replaced.

In England and Wales, you can use an installer registered with a Competent Person Scheme (BSI, CERTASS or FENSA). A registered installer will be approved to carry out the work to comply with BR without involving local authority building control. When work is complete, you will receive a certificate showing the work was done by a registered installer.

Alternatively, you can use an unregistered installer or do it yourself, in which case, you would need to get approval from the relevant Building Control Body – either at your local authority or an Approved Inspector. They will check the replacement window(s) or door(s) for compliance, and if satisfied, issue a certificate of compliance or regularisation certificate.

See our section 'Approval for building works', for more information.

Thermal heat loss

Dwellings are required to be energy efficient. A method of achieving greater energy efficiency is to take steps to reduce the amount of heat that is lost through the glazing in both windows and doors.

If you are to install windows and doors, you should be aware that they need to comply with BR requirements in relation to the amount of heat that can pass through the glass and framework. The actual value of the maximum permitted heat loss is set out in technical guidance published by the Department for Communities and Local Government (this also acts as a good guideline for Northern Ireland).

Safety glazing

Safety glazing should be provided to any glass in a critical area. Below is a list giving general view as to when safety glazing is required:

  • Any glazed area within a window below 800mm from floor level
  • Any glazed area within a window that is 300mm or less from a door and up to 1500mm from floor level
  • Within any glazed door up to 1500mm from floor level


Windows and doors provide ventilation to rooms within a dwelling and rules apply to how much ventilation. The type and extent of ventilation will be dependent on the use and size of the room. For example, rooms where steam will be produced (kitchens, bathrooms, utility rooms etc.) should be provided with higher levels of ventilation (normally mechanical fans and windows) than other rooms where suitably sized window openings and background ('trickle') ventilators may suffice.

Fire safety

There are two aspects to be considered:

  • Fire spread between properties through 'unprotected areas'
  • Means of escape in case of fire

Unprotected areas

External doors and windows may need to have fire resistance and (in the case of doors) be self-closing or (in the case of windows) be fixed shut to limit the risk of fire spread between adjacent properties. The area of walls, doors and windows permitted to have reduced or undetermined fire resistance (known as 'unprotected areas') will be dependent on how close these elements are to the boundary.

Means of escape

A room should be served by a window or door suitable for escape if:

  • The only other way to exit the room is via another room (except if the room is a kitchen, laundry room, utility room, dressing room, bathroom, W.C. or shower room)
  • The room is on the first floor of the dwelling (subject to its floor not being more than 4.5m above ground level)

When replacing any window, the opening should at least have the same potential for escape as the window it replaces. If the original window that is being replaced was larger than necessary for the purpose of escape, then the new window opening can be reduced down to the minimum BR specification.

It is also generally good practice to replace any window on the first floor that is not used as an escape window with an escape window.

Access to buildings

When replacing main entrance doors in a dwelling unit that has been constructed since 1999, it is important to ensure that the threshold remains level; otherwise the works will not comply with the BR as it would be making the threshold worse than it was when constructed. This is to enable a wheelchair user to have continued access to the dwelling.

Fascias & soffits

The replacement of fascia and soffit boards will not normally require approval.

Fascia boards – these are boards attached to the end of the rafters/trusses at the eaves, where the guttering is attached for the roof rainwater drainage. These are also placed at the ends of gable roofs to cover the rafters/trusses.

Soffit boards – these are placed on the underside of the eaves where the roof overhangs the walls. You should check that the replacement work does not reduce the ventilation provided to the roof, because this could cause condensation to occur within the roof void, which can lead to damp on the timbers.


The work needed to maintain drainage pipes does not normally require BR approval as long as the work is a repair and any replacement necessary in the process is as like for like as reasonably possible.

Gutters and drainpipes

The replacement of existing guttering does not normally require approval under the BR as long as the work is a repair and any replacement necessary in the process is as like for like as reasonably possible.

Public sewer

If your proposed building works are going to be within 3.0m of a public sewer and/or you are to connect new drainage to a public sewer system, you must contact your local water authority and inform them of the proposed works. In Northern Ireland all sewers are public unless you have a septic tank, in which case, it is most likely private. You will still need to apply for consent from the Department of the Environment for Northern Ireland to work on a private sewer in Northern Ireland.

Private sewer (England and Wales only)

Private sewers are not owned by the water authority, but instead, by the home owners who use them. In general, most private sewer systems were constructed after 1939. You should contact your local water authority to determine if your sewer is public or private. The maintenance and upkeep of private sewers is usually the responsibility of those who use the drainage system.

If you wish to carry out works that could affect other users of a private sewer, then you should notify them and get their permission.

New boiler

Work to install a new boiler or a cooker that also supplies central heating (Aga, Raeburn etc.) needs BR approval because of the safety issues and the need for energy efficiency. This is generally achieved by employing an installer who is registered under an approved scheme.

  • Gas boiler – The installer should be Gas Safe registered
  • Oil fired boiler – The installer should be OFTEC registered
  • Solid fuel fired boiler – The installer should be a member of HETAS

Internal walls

Removal of internal walls

Care should be taken before removing any internal wall. These walls can have a number of functions that could affect the building and the safety of the occupants within the building, such as:

  • Load-bearing: supporting another part of the building (floor, wall, roof etc.)
  • Means of escape: providing separation for fire safety (e.g. enclosure of a stair)

Load-bearing walls

A load-bearing wall is one which supports other elements of the building, such as (and most commonly) the:

  • Roof - part of the roof structure which would include the ceiling joists within the loft area are sometimes supported from internal walls.
  • Wall above - there is possibility that if another wall sits directly above, then it could be supporting that wall
  • Floor joists - floor joists are sometimes built into or sitting on top of an internal wall.

These are the most common parts of a building that an internal wall could be helping to support; however there are other things to look for. An example could be where the chimney breast has been removed on the ground floor. A beam may have been placed across the underside of the chimney stack to support it, which then sits on an internal wall to transfer the load down to the foundation.

A structural engineer or surveyor can be employed to determine if the wall is load-bearing and then design a beam to cater for these loads.

New internal wall(s)

Work to provide a new internal wall generally requires approval under the BR.

Installing a new skylight

A skylight is a window that is installed within a pitched roof or flat roof normally to give more light to rooms or spaces within the home. Building Control approval will generally be needed for the installation of a new skylight for the following reasons:

  • The roof structure will normally need to be altered to create the opening for the skylight
  • The roof will have to be able to carry the load (weight) of the new skylight
  • Any skylight that is installed will need to prove that it has sufficient insulation against heat loss i.e. is energy efficient
  • If the skylight is in close proximity to a boundary, the fire performance of the skylight will need to be considered

External walls and coatings


Re-decorating the surface of an existing wall would not normally require approval.


External walls are considered to be thermal elements and renovation of a thermal element will probably trigger a requirement to upgrade the thermal insulation of that element at the same time.

Internal decorations

Any internal decorating such as wallpapering, new skirting boards or painting will not normally require approval.


After a period of time the roof on existing buildings will need to be replaced. In most situations, this work will need Building Control approval.

Flat roofs

Some repairs to flats roofs will not require an application for approval under the BR. However, if a roof with integral insulation is to be replaced, then you may be required to upgrade this thermal element of the structure and reduce the amount of heat that was originally lost, by upgrading the insulation.

Pitch roof

If the existing roof covering is to be replaced with a different material to its original, for example slate to tiles, then Building Control Approval is likely to be needed to ensure the roof will be adequate in terms of structural stability (applicable where the replacement tile will be significantly heavier or lighter), and also to ensure that it meets requirements in respect of fire safety and energy efficiency (see above).

If the new roof covering is significantly heavier or lighter than the existing one, the roof structure may need modifying and/or strengthening, and you should check with a structural engineer or surveyor before commencing with works.

Energy efficiency

As a roof is defined as a thermal element, the work to re-cover a roof should also include for improving the thermal insulation properties of the roof.

For more information see our 'Energy-efficient homes' section.

Copyright © 2024 Epoq Group Ltd. All trademarks acknowledged, all rights reserved

This website is operated by Epoq Legal Ltd, registered in England and Wales, company number 3707955, whose registered office is at 2 Imperial Place, Maxwell Road, Borehamwood, Hertfordshire, WD6 1JN. Epoq Legal Ltd is authorised and regulated by the Solicitors Regulation Authority (SRA number 645296).

Our use of cookies

We use necessary cookies to make our site work. We would also like to set some optional cookies. We won't set these optional cookies unless you enable them. Please choose whether this site may use optional cookies by selecting 'On' or 'Off' for each category below. Using this tool will set a cookie on your device to remember your preferences.

For more detailed information about the cookies we use, see our Cookie notice.

Necessary cookies

Necessary cookies enable core functionality such as security, network management, and accessibility. You may disable these by changing your browser settings, but this may affect how the website functions.

Functionality cookies

We'd like to set cookies to provide you with a better customer experience. For more information on these cookies, please see our cookie notice.