Permitted Development for Houses made simple
This blog summarises permitted development [PD] rights for residential dwellings. In the majority of cases the guidance is pretty straightforward. However, beware! In some cases, it most certainly isn’t.
If, having read this blog, you need to check out the position in more detail, the Government’s document “Permitted development rights for householders: technical guidance”gives a lot more detail in a fairly digestible way. Follow this link to read it:
New permitted development rights relating to increasing the number of storeys on houses were introduced in 2020. They are in addition to everything else included in the above guidance and this blog.
Before you start
Here are a few points to note at the outset.
· Permitted development [PD] is development that you can carry out without needing to apply for specific planning permission. You may still need approval under other legislations such as Building Regulations or Party Wall provisions;
· If you live in a Conservation Area, Area of Outstanding Natural Beauty (AONB), the Green Belt or the Canterbury World Heritage Site what you can do under permitted development will be more restricted. If your house is Listed, not only is permitted development more restricted in some cases, but you may also need Listed Building Consent in any event;
· You must also check whether your house is in an area where the Council has made a direction by removing permitted development rights, or whether your house has previously been subject to a condition removing PD rights;
· Permitted development rights can differ depending on whether your house is detached, semi-detached or terraced. They do not generally apply to flats or houses in multiple occupations;
· The guidance will frequently refer to the “original dwelling house”. That is the house as it existed on 1 July 1948, if built before that date, or when construction was completed, if built after 1948;
· Development in terms of dimensions or volume is cumulative so in your calculations you must take into account everything previously built on to the original dwelling house whether by permitted development or with planning permission;
· In some cases, even if work is permitted development, you will need to consult your neighbour or seek‘ prior approval’ from the Council.
If this is something you think you would like to explore, please read on.
Enlargement, improvement or other alterations
You can alter or extend your house providing:
· It does not take up more than 50% of the curtilage of the original dwelling excluding the area of the original house itself;
· It is not higher than the highest part of the roof [excluding any chimneys];
· The eaves height is not above the eaves height of the existing house;
· It is not in front of the existing house or on any side of the house that faces a road [unless it’s a porch in which case see below].
Single storey rear extension:
· If it’s in a Conservation Area or AONB it must not go more than 4m beyond the rear wall of the property if it’s a detached house, or 3m for any other dwelling;
· If it’s not in aConservation Area or AONB it must not go more than 8m beyond the rear wall if the property is detached, or 6m for any other dwelling;
· In both cases it must not be more than 4m high.
Or if it’s a two-storey rear extension, which can only happen outside a Conservation Area or AONB:
· It must not extend more than 3m or be within 7m of the boundary facing the rear wall of the house.
If any extension is within 2m of the boundary of the curtilage, the eaves height must not exceed 3m.
If it’s a side extension, and this can only happen if the site is not in a Conservation Area or AONB, then:
· It should not exceed 4m in height;
· Be more than single storey;
· Have a greater width than half the width of the original house;
Any extension, rear or side, should not include a veranda, balcony or raised platform.
In all of the above:
· the materials used must be of a similar appearance to the existing;
· upper floor windows must be obscure-glazed and, if less than 1.7m above floor level, fixed.
Lifting the roof [this is new]
Unless the house is in a Conservation Area or an AONB, two additional storeys can be added to houses consisting of at least two storeys, and one additional storey can be added to a single storey house providing:
· The new storeys are above the top most storey;
· The house was built between 1 July 1948 and 28 October 2018;
· The house has not already had a storey added;
· The proposed structure is not more than 18m high, or it exceeds the highest part of the existing roof by 3.5m for one storey or 7m for more;
· For a semi-detached house, the roof is not more than 3.5m higher than the building with which it shares a party wall, or if it’s terraced any other building in the same row;
· The new storeys are on the main part of the original house, not any extensions;
· No visible support structures are provided;
· There are no windows in walls or roof slopes on side elevations;
· Materials used are similar to the existing.
Two things to especially emphasise:
· Before implementing these permitted development rights the prior approval of the Local Authority is required;
· Although these rights also apply to Listed buildings, Listed Building Consent will always be required in any event.
More modest work to the roof
Additions or alterations to the roof must not:
· Take place if in a Conservation Area or AONB;
· Exceed the existing roof height;
· Project beyond the existing roof plane if on the front elevation;
· If windows [such as Velux] are to be inserted in the existing roof plane, project more than 0.15m from the existing roof plane;
· Exceed the volume of the existing roof by more than 40m if a terraced house or 50 cubic metres in all other house types;
· Extend beyond the outside walls of the original dwelling house;
· Include a veranda or balcony;
· Take place on any house to which additional storeys have been added.
Additions to the roof must:
· Use similar materials to the existing;
· Maintain the existing eaves;
· Be set in a minimum of 0.2m from the existing eaves;
· If windows are inserted in a side elevation, use obscure glazing and be fixed if less than 1.7m above floor height.
A porch may be erected outside any external door providing:
· It is less than 3 sq m in area;
· Less than 3m in height;
· More than 2m from the boundary of the property which fronts a highway.
Freestanding buildings in the curtilage
Unless the house is listed, buildings in the garden for domestic purposes such as separate garages, sheds, play houses, swimming pool enclosures, and animal runs may be erected providing they:
· Occupy less than 50% of the curtilage;
· Are not in the front garden;
· Are single storey;
· If they have a pitched roof, are less than 4m high and more than 2m from a boundary;
· If they have any other roof, are less than 3m high and more than 2m from a boundary;
· Are 2.5 m high if less than 2m from the boundary;
· Have an eaves height of less than 2.5m;
· Have no veranda or balcony included.
In addition, oil or gas containers of less than 3,500 litres can be erected.
If you are in a Conservation Area or AONB the total area of ground covered by any building situated more than 20m from the house must not exceed 10 sq m.
A hard surface for a use related to the house [e.g. parking cars] may be built providing:
· It is in front of the house and/or greater than 5sq m, and is constructed of porous material or provision is made for run off to a porous area within the curtilage.
And finally, chimneys and flues
A chimney or flue may be built, replaced or altered providing:
· It is not more than 1m above the highest part of the existing roof;
· If you are in a Conservation Area or AONB, it is not on the front roof or wall.
This summary is intended as a guide.
It is always advisable to check whether specific proposals are permitted development either by contacting any member of James Clague Architects, who will be happy to help, or by looking at the detailed legislation. No responsibility is accepted for independent action taken on the basis of this guide.
Domestic planning approval granted for a two-storey front extension and single storey rear extension to a former school in the Kent Downs Area of Outstanding Natural Beauty.
James Clague Architects have obtained Planning and Listed Building Consent from Tonbridge & Malling Borough Council (TMBC). The property is a Grade II Listed private dwelling located within the Greenbelt outskirts of the town of Tonbridge.