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Conservatory Planning Permission - Conservatory Building Regulations - Changing your windows


Choosing the right company when buying a conservatory or windows and doors, can take the hassle out of organising Planning Permission and Building Regulations.

Building Regulations set standards for the design and construction of buildings to ensure the health and safety for people in or about those buildings. They also include requirements to ensure that fuel and power is conserved and facilities are provided for people, including those with disabilities, to access and move around inside buildings.


Planning is interested in the way our towns, cities and countryside is developed.  This includes the appearance of buildings, the use of land & landscaping considerations, highway access and the impact that the development will have on the general environment. A lot of these factors don’t need to be considered for a conservatory build BUT some do!


Neighbour consultation scheme

This scheme only applies to larger single-storey rear extensions which are permitted for three years between 30 May 2013 and 30 May 2016. This means that extensions of between four and eight metres for detached houses and between three and six metres for all other houses, must go through the process.


Conservatory Planning Permission – Building Regulations – Solar Panels – Porches – Regulations for Windows & Doors


Before you commit yourself to a new conservatory, a porch, solar panels or replacement windows/doors it is worth making sure that you have complied with all the relevant regulations.


The following is a synopsis of the regulations as we interpret them. Local authorities may apply them differently so it is imperative that a definitive answer is obtained from your relevant authority. We can undertake this on your behalf as part of our Project Management service.


Conservatory Building Regulations


The following only applies in England and Wales.

Conservatories have been exempt from Building Regulation control (since the mid-’80s) providing they comply with the following:

  • The floor area must not exceed 30m² (measured internally.)


  • The conservatory is separated from the house by either external quality walls, doors or windows


  • It must be built at ground level.


  • There should be an independent heating system, separated from the house system


  • The glazing must comply with the safety requirements of Building Regulations part N.


  • 75% of the roof must be transparent or translucent.


Further, the following are regarded as being ‘good practise’:

  • The conservatory should be more than one metre from the property boundary.


  • It should be built of non-combustible material.


  • It should be a single storey building.


  • There should be a door separating it from the house.


  • Base work should not interfere with any drain or sewer.


Conservatory Planning Permission


There are many complex factors that will determine whether your conservatory will or will not require planning permission and although the planning laws on conservatories were relaxed in 2008, there are still factors that mean that you may require planning permission. The first thing to find out from your local authority is whether ‘Permitted Development Rights‘ have been removed from your property. This can be quite common on modern housing estates and if they have been removed, planning is required whatever the size.


Other general rules on a semi-detached or terraced house is the projection of the conservatory must be no more than 3m, on a detached house this increases to 4m, if the external projection is above these sizes then planning is required. Please note these sizes are off the rear of the original house wall, so if you are trying to attach a conservatory to an extension then permission would probably be required. Other rules include:


  • No more than half the area of the land around the original house footprint is covered with extensions/conservatories


  • No extension forward of the principal (front normally) or side elevation fronting a highway


  • No extension to be higher than the highest part of the house roof


  • Maximum height of the conservatory is 4m


  • Maximum eaves height (generally gutter height) must be 3m, if within 2m of the boundary


  • Side extensions to be single storey with maximum height of 4m and width no more than half that of the original house.


  • Where work is proposed to listed buildings, listing building consent may be required.


  • The term “original house” means the house as it was first built or stood on the 1st of July 1948 (assuming it was built before that date)


We do provide a full planning service via our architect and would be happy to advise you further on Planning Permission.


It is worth repeating at this stage that the above is only our interpretation of the regulations. You should ensure that the relevant permissions are in place from the relevant bodies before proceeding.


Visit the Planning Portal – The Planning Portal is the UK Government’s online planning and building regulations resource for England and Wales. A good interactive guide for conservatories can be found here.


Porches/Porch Planning Permission


The planning rules for porches are applicable to any external door to the dwelling house.

Adding a porch to any external door of your house is considered to be permitted development, not requiring an application for planning permission, provided:

  1. The ground floor area (measured externally) would not exceed three square metres.
  2. No part would be more than three metres above ground level (height needs to be measured in the same way as for a house extension).
  3. No part of the porch would be within two metres of any boundary of the dwelling house and the highway.

The Planning Portal mini-guide for porches can be found here.


Doors and Windows in Conservation Areas/Listed Buildings


Planning permission is not normally required for repairing, fitting or replacing doors and windows (including double glazing). However, if the building is listed or is in a conservation area (or other designated area) you should consult with your local planning authority.

Also, if you are a leaseholder, you may first need to get permission from your landlord or management company.

Further information from the Planning Portal can be found here.


Replacing windows in flats


Permission for changing windows in flats or maisonettes differs in many important ways to houses. See the check list below

  • Installing secondary glazing should not require planning permission


  • Fitting windows that are identical in appearance and colour should not require planning permission


  • If you are the leaseholder you should seek permission from either the management company, landlord or freeholder


  • If your flat is in a listed building you will need listed building consent and you should contact your local planning authority for advice on design and materials.


Local policy and interpretation of the rules covering changing windows in flats varies from council to council and you are advised IN ALL CASES to contact your Local Planning Authority for advice before starting work.


Doors and Windows Building Regulations


Since April 2002, building regulations have applied to replacement windows & doors. The installation company must either be registered with a competent person scheme (BSI, FENSA, CERTASS are a few) This would mean that you will receive a certificate at the end of the installation. These will be required if you sell your property! If they are not fitted under this scheme (by an unregistered installer or DIY) then approval must be sort from your local Building Regulation authority/council

Further information from the Planning Portal can be found here.


Solar Panels


In many cases fixing solar panels to the roof of a single dwelling house is likely to be considered ‘permitted development’ under planning law with no need to apply for planning permission. There are, however, important exceptions and provisos which must be observed. These permitted development rights apply to houses. If you live in a flat and are considering fitting solar panels you are advised to contact your Local Planning Department for guidance.

Further information on Solar Panels from the Planning Portal can be found here.

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