HTF Guidance Note 2 – March 2011, updated Aug 2024
Work that is controlled under The Building Regulations
This guide will inform you about the type of domestic work that comes under the control of the Building Regulations. In other words, it is work related to a house or flat for which it is a legal requirement that the owner needs to submit a building regulations application in advance of carrying it out. You will find separate guidance on how to make an application on our website. We have listed controlled work in the following categories and given further information on each below:
- Erecting and/or extending a building
- Changes of use from or to a dwelling
- Alterations that will ‘materially affect’ compliance with certain regulations
- Work to controlled services
- Renovation of thermal elements
Erecting or Extending a Dwelling
Most people will know that it is necessary to seek Building Regulations permission in addition to planning permission if you plan to build a new house of block of flats. Subsequent extensions to such buildings are also usually controlled although certain types such as porches, conservatories and covered ways/carports may be exempt from control. You can find further guidance on these exempt categories of extension in our guidance.
Changes of Use
Changes of use to any building to create houses or flats is controlled work as is work where a building contains a greater or lesser number of individual dwellings.
If you plan to change the use of only part of a building from a non-habitable to a habitable use, then that’s also controlled work requiring that you make an application. That might be a garage conversion or a loft conversion and rules apply to ensure that they are safe, healthy and energy efficient.
Alternatively, it may be that you are proposing to change the use of an existing dwelling to another purpose. Some such changes are controlled including to a hotel or boarding house or a shop. Taking in lodgers or sharing a dwelling with non-family members isn’t controlled if people are living together as a single household, ie with all occupants sharing the facilities. There is a limit of 6 persons in such an arrangement after which it becomes a controlled change of use.
You can also set up a small office, surgery or consulting room in a house to be used by an occupant in a professional or business capacity and this would not be classed as a change of use.
‘Material’ Alterations
There are many alterations that you can carry out to your home without needing to make an application under Building Regulations. Those that do, generally fit into 3 categories;
Structural Alterations – affecting the structural elements such as foundations, loadbearing walls, floors or roofs. Works in this category include underpinning, new door and window openings, removing loadbearing walls (‘knock-throughs’) and removing chimney breasts. Adding solar panels to a roof is also controlled as is replacing a roof covering with a heavier or lighter material
Alterations that may affect fire safety – Such as removing or replacing fire doors or layout changes that affect the protected routes of escape from a house in a fire. Alterations to a smoke detection/alarm system would also be covered.
Alterations that adversely affect the accessibility of the dwelling to people with disabilities – The removal or alteration to a wheelchair accessible entrance or to a ground floor accessible WC to a house are examples.
There is another type of alteration that comes under Building Regulations control and that’s where an exempt building or extension is altered so that it no longer meets the criteria for exemption (see our guide on exempt buildings (ADD LINK). A typical example of this would be where an exempt conservatory or porch has the separation from the main house removed or the translucent roof is replaced with a solid roof. Another example is where detached buildings are adapted for use as sleeping accommodation.
Work to Controlled Services and Fittings
These are services and associated fittings such as electrical and drainage (sewage, wastewater and rainwater disposal) systems, fixed hot water and heating systems and fixed cooling systems. Windows and doors between heated and unheated spaces are also a type of controlled fitting. Examples of controlled work in this category are;
Replacement Windows – note you don’t have to make an application is registered with one of the government-approved competent persons schemes (CPS) such as FENSA
New or Replacement Heating or Cooling Appliances – such as boilers, solid fuel stoves and fixed air conditioning units. Controls relate to their safety, energy efficiency and carbon emissions. There are also competent persons schemes covering this type of work and this is covered in our separate guidance
New or Replacement Central Heating – The regulations look for these to meet current standards of energy efficiency.
Installation of New and Replacement Bathrooms, Kitchens and Utility Rooms – The associated drainage alterations are controlled but not if there is negligible change to the existing drainage pipe layouts.
Electrical Works – Controlled under Part P of the regulations and all work should be installed, inspected and tested by a competent electrician. If you are not using a CPS registered electrician, then you will need to make an application for any work to replace the consumer unit or create a new circuit. Electrical work in rooms containing baths, showers, swimming pools or sauna heaters are also controlled and notifiable.
Renovation of Thermal Elements
This final category of controlled work covers repairs, refurbishment and upgrades to roofs, ground floors and external walls. That might be the addition of extra layers or replacement of existing layers. It’s an opportunity to consider the viability of upgrading the element to a better thermal resistance in order to conserve energy and reduce carbon emissions.
Major renovations are controlled where more than 25% of the thermal envelope of the building are renovated or more than 50% of an individual element. Typical examples of this type of work would be:
- Replacing the waterproof membrane on a flat roof
- Re tiling a pitched roof
- Rendering or cladding an external wall
- Internal replastering or dry lining of an external wall
The regulations and Approved Document L set targets for improved thermal performance depending on the existing performance. If an upgrade would not be viable for technical, economical or functional reasons then we would not insist on you meeting those targets.
Further Advice and Information
It has not been possible to cover every aspect of controlled work so you shouldn’t consider this as comprehensive guidance. You are welcome to contact us for more detailed advice on domestic work on your Hertfordshire property by calling us on 01438 879990
