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Planning Section
Worthing Borough Council
Portland House
Richmond Road
Worthing
West Sussex
BN11 1LF - 01903 221065
- planning@worthing.gov.uk
Extending or Altering Your Home
Introduction
This design guide relates primarily to proposals for extensions to residential properties. It does not seek to impose detailed design controls, but gives general advice and sets out a number of design principles.
You can make certain types of minor changes to your home without needing to apply for planning permission. These are called "permitted development rights". The size and types of development that do not require planning permission are explained on the Planning Portal website. With domestic proposals most permitted development rights extend only to houses and not to flats. In some local areas permitted development rights are more restricted. If you live in a Conservation Area, a National Park, or an Area of Outstanding Natural Beauty you will still need to apply for planning permission for certain types of work which do not need an application in other areas.
There are also different requirements if the property is a listed building.
Worthing Borough Council may have removed some of your permitted development rights by issing an Article 4 direction. This happens when the character of an area of acknowledged importance would be threatened.
Alternatively the Council may have removed some of your permitted development rights by a conditon on the original approval for the house or estate. You would usually know if your property is affected by such a direction or conditon but you can contact Planning Services to check.
The principles contained in this design guide are relevant whether planning permission is required or not. If followed, they should safeguard residential amenity and result in an extension that is sympathetic in appearance to the existing house. As these guidelines are supplementary policy guidance, they will be considered in the assessment of planning applications. Although planning permission can never be guaranteed, an extension that accords with this guide is more likely to receive planning permission than one that does not.
Whilst you may be concerned that good design could increase the cost of your extension, this is not necessarily so. Although the best design and using the most appropriate materials may sometimes add to the initial costs, these are likely to be amply paid back in reduced maintenance costs and an increased resale value for your house. You also have the satisfaction of an extension that blends with the appearance of your property and with the street scene.
Please note that accurate plans are essential before commencing work and by employing a suitably qualified professional person to draw up your plans, you can avoid many of the pit-falls that await those not so experienced in such work.
General Principles
When designing an extension and deciding on an appropriate siting, the two most important things to ensure are; that the design of your extension achieves an appropriate relationship with the design of the existing house and; that it also takes into account any impact on the street scene. To achieve this, you will need to consider carefully the following:
- the size and shape of the extension;
- the materials to be used;
- the design and positioning of doors and windows;
- the effect on the privacy of neighbours and the light reaching their property; and
- the effect the extension will have on the character and appearance of the street.
The Size and Shape of the Extension
The size and shape of any extension should normally be designed to ensure the original house remains the larger and more dominant feature. Therefore, the extension should not be higher than, or in front of, the main house. With semi-detached properties, it is preferable to set back side extensions from the front wall of the original house. This also has the advantage of stopping any awkward bonding of new and old brickwork on the front elevation.
In order to ensure that your extension relates well to your house, its design should be consistent with your existing property's style and shape. If your extension will be visible from the street, it is important to ensure that the roof form of the extension is similar to that of the existing house. For example, if the main house has a pitched roof, the roof of the extension should have the same style and pitch. The eaves level of a two-store extension should preferably line through from the house and must never be higher than on the existing house.
- Unsightly extensions ignoring the style and shape of the original house
- Flat roofs clash with existing pitched roofs
- Inappropriate window types and sizes
- Overly large and obtrusive dormer
- Different materials to the existing house have been used
- New extension harmonises with existing house style
- Pitched roofs compatible with existing
- Eaves line up with existing
- Materials and detailing match up with original house
Where possible, false pitched roofs, i.e. trying to conceal a flat roof behind a short sloping roof should be avoided. This is because the outer corner will often be visible, revealing that it is no more than a decorative applied facing.
If the proposal is for a glazed conservatory, it should be carefully designed to match the style of the dwelling and be sited and/or designed to avoid overlooking adjacent properties. Obscure glazing may be needed in some elevations of the conservatory.
Materials
The facing materials of any extension should ideally match those used for the existing house. If identical materials are not available, the nearest possible alternative should be used. When selecting materials, you should ensure that they match the originals in size, shape and texture.
Roof tiles can often be reused from where the extension roof to the existing property, is made. If there is a problem in making a close match, tiles can be removed from the back of the house and used for the front of the extension, whilst the new materials are used at the rear.
Doors and Windows
The proportions of existing buildings and in particular the relationship between walls and openings, such as doors and windows, and the shape of those openings should be considered when designing an extension. New windows should always be of the same opening type and style as those existing, whilst the new lintels and sills should line up with those of the old.
Your Extension and Your Neighbours
A carefully designed extension is important in order to reduce its potential impact on your neighbours. Such consideration should avoid any excessive loss of light and privacy and will reduce any overbearing effect of the extension.
As most dwellings have the main windows to principal rooms facing towards the front and back of the property, extensions close to a neighbour's boundary can significantly reduce the amount of daylight and sunlight reaching the principal rooms of adjoining houses. Whilst each application is considered on its own merits, this problem can often be overcome in the case of single store extensions by ensuring that they do not project more than 3m (10 ft) from the rear wall of the original dwelling house.
However, there are some important exceptions to this rule, where this depth may need to be reduced, of can be increased. For example:-
- where there is a difference in levels between the property being extended and the neighbouring properties;
- extensions to older buildings which would require higher ceilings to be consistent with the original house;
- where the extension lies to the south of the neighbouring property; and
- where the extension will cause a "tunnelling effect".
Overlooking may also be a problem when the principal rooms face each other. In this case, adequate privacy can normally be achieved by retaining a minimum garden length of 10m (33ft). However, the relationship of any other surrounding properties will be a matter with which the Council will have to have regard to in terms of the potential loss of privacy.
In order to respect your neighbour's privacy, avoid positioning windows in the side wall of any rear extension, which would be on or close to the boundary with your neighbours. An exception can be made if the window serves a secondary room such as a toilet or bathroom, where a high level window or obscure glazing can be used.
Side Extensions
If your property is detached or semi-detached, you should avoid designing a two-store side extension up to the property boundary. Several such extensions in one road will dramatically alter the street appearance, from one of well spaced rhythm to a row of terraces properties. This is known as the "terracing effect". To prevent this, a minimum of 1m (3ft 3") should normally be maintained between an extension and the boundary of your property. This will also have the benefit of leaving room for maintenance. Where space will allow, more than 1m should be left at the boundary. In "Established Low Density Housing Areas", which are characterised by a spacious, low density layout where existing houses are sited a good distance from site boundaries, the minimum of 1m between boundaries and two-store extensions will be inadequate and significantly more space should be provided.
If your property is in a plot next to the junction with another road, you should take care not to breach the building line in this other road. A two-store side extension is unlikely to be acceptable in these circumstances.
In the case of single-store extensions, problems caused by the encroachment of foundations or guttering can arise if the extension is too close to a boundary. A minimum of 300mm (1ft) between the side wall of a single-store extension and the property boundary should be provided where possible.
Front Extensions/Porches
Front extensions/porches are usually highly visible and can therefore drastically alter the appearance of a house and the character of the street. Remember, the first impression of your house is all important.
If the properties on your street conform to a strict building line, any front extension disrupting this line will probably become obtrusive in the street scene. However, if there is a staggered building line, a front extension may be possible.
Particular care must be taken if your property is semi-detached, or forms part of a terrace. As terraces have a uniformity of design, with repetition of design details, an unsuitable front extension/porch can spoil the look of the whole role. Ready-made porches consisting of glass or timber boxes may be convenient for mass production, but are rarely as successful as designs specifically tailored to the individual house. Where front doors are paired, a joint scheme should be considered.
Roof Extensions and Dormers
Roof extensions and dormers are often highly visible and alien features which greatly alter the appearance of a dwelling. Therefore, there is a normal presumption against dormer windows that are visible from the street. However, exceptions to this can be made if the dormer is located at the rear of the property to make it less visible, or if several other dwellings on the street already have dormer windows, which are not substantially out of character.
Dormers should never be allowed to dominate the roof by being overly large or higher than the existing roof ridge. Where possible they should be designed to follow the vertical lines of existing windows. Always, avoid wrapping dormers around more than one face of the roof, or cutting into the line of the hip.
Hipped roof or gable ended dormers are often preferable to those with flat roofs, because they reduce the overall "bulk" of the extension. This also avoids the horizontal emphasis that is produced by large flat roofed dormers. In some cases a roof light may form a more suitable alternative to a dormer.
Whilst the windows themselves should match those of the existing building, the roofs and sides of new dormers should be covered in materials which match or compliment the main roof.
Garages and Parking Spaces
As with other extensions, it is better to set a garage back from the front of a dwelling, especially if it is to be attached.
The use of different types of garage in a street frontage can destroy the harmony of the street scene. The use by adjoining owners of similar garages will avoid this and help to maintain the rhythm of the original house design. Due to the number of different garage door styles available, care should be taken to blend the style with the house.
Always remember that when an extension includes a garage, there must be a distance of 6m (20ft) between the garage and the back edge of the footpath. This allows a vehicle to be parked safely off of the footpath without hindering pedestrians and leaves enough space for the garage door to be opened whilst the vehicle is parked in the drive.
Please note the extension of a dwelling may result in additional parking requirements, the details of which are explained in Worthing Borough Council's publication "Parking Right! A Guide to Off-Street Parking Requirements in Worthing".
The Building Regulations
In addition to requiring planning permission, you may need to obtain approval under the Building Regulations, which is a separate process and should not be confused with planning legislation. Indeed, most alterations and extensions will require consent under the Building Regulations.
The overriding purpose of the Building Regulations is to ensure the health and safety of people in and around buildings, lay down required levels of performance and deal with the actual construction of building works.
If you wish to have an informal discussion or seek further information and guidance, please contact the Building Control Group, who will be please to help.
Further Advice
In Conservation Areas and with Listed Buildings, design details are more strictly enforced. It is advisable to check at the outset whether this applies to your property.
As previously mentioned, not all extensions to houses and bungalows require planning permission. It is therefore advisable to obtain written confirmation from the Planning Section as to whether planning permission is required. This may be a complex question to answer and therefore you will be asked to give a number of details on a simple form, available from the Planning Section, at the address given below, in order that we may expedite the assessment of your proposed extension.
In addition it should be noted that the actual construction of most types of alterations and extensions is controlled by Building Regulations. As such an application must be made, or a Building Notice submitted before commencing any work. If you wish to have an informal discussion, please contact the Building Control Section at the address below and one of our Building Control Officers will be pleased to help.
If you have any questions concerning the guidance contained in this planning guide, staff of the Planning Section will be pleased to help you. As well as contacting the number below, you may call in at our reception, during normal office hours. A Planning Officer is normally available between 10 a.m. and 1 p.m.
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