Find information on design principles below.
As a general rule, extensions should not appear to dominate the original house or neighbouring properties. They should complement the design of the original property and the wider area, in terms of scale and design.
Under this approach, the original house should be dominant and all extensions should appear as sympathetic additions. A well-designed subordinate extension will help to maintain the original appearance of a house and the wider area, and are a good option in most instances.
Dwelling with a subordinate extension
Extensions can be designed to appear as part of the original house. If the design and building materials match in with the existing, the approach can work well for extensions to detached houses and extensions to the end of uniform terraces. However, this approach is not always appropriate for extensions to semi-detached properties.
Dwelling with an integrated extension
Roof and wall materials of extensions should match or complement those of the existing building. This will help to ensure that extensions and alterations sit well against the original property and the wider area. Poorly matching or uncommon materials can damage the character of a building. New wall or roofing materials should match the existing unit sizes, coursing, texture, pointing and colour (where applicable). In some cases, reclaimed materials may need to be used typically within a Conservation Area.
Proposed materials matching the existing dwelling
The use of non-matching materials can appear complementary to the existing materials (often on modern extensions to older properties). This will depend upon the overall quality of the design and how it looks in context. Material samples may be requested in this instance prior to approval being given.
Proposed materials complementary to that of the existing dwelling
Buildings often have architectural features and details which contribute to their character and appearance. When designing an extension, it is often desirable to replicate features such as opening pattern, window lintels/sills, eaves detailing, gutters and rainwater pipes.
Proposed extension matching the features of the main dwelling.
It is not necessary to incorporate grand or intricate detailing for the design of small extensions. Where buildings have ornate features and details; simpler extensions can be preferable so as not compete with the main building. Generally, unless a high quality contemporary design is proposed, it will normally be appropriate to replicate basic features and details.
Proposed simple extension against an ornate building
Extensions should respect and integrate with the street scene. Proposed openings and its overall form should reflect proportions, design and layout of the properties around it. If a building has a well-balanced pattern of openings, the addition of too many windows, which are not aligned and of various sizes, will cause disruption and harm the look of a building and street scene. This would also apply to the addition of dormer windows.
A porch extension that matches the window pattern and form of the street scene
Overlooking and loss of privacy
Overlooking occurs where there is insufficient distance and unrestricted views between an opening or platform and a neighbour’s existing window or private garden. Direct views into habitable rooms such as reception rooms, kitchens and bedrooms are particularly sensitive. Bathrooms, store rooms, hallways, landings and garages are not as sensitive.
An extension that impacts privacy
Overbearing impact and outlook
Extensions or outbuildings can sometimes have an over dominating physical presence that damages the outlook of neighbours. Whether or not an extension or outbuilding has an over-dominating impact will depend on its overall size, the distance between neighbouring properties, and the position of habitable room windows or well used parts of the garden beyond boundaries.
An extension that has an overbearing impact
Loss of light
In many cases, extensions and outbuildings that have an overbearing impact upon their neighbours, will also cause an unacceptable loss of light to neighbouring properties and their gardens dependant on the orientation of the property.
An extension that causes loss of light
Where there is an increase in habitable accommodation, it will be expected that the in-curtilage parking provision should be addressed to cater for any increased demand or loss of spaces to prevent adverse effects on highway safety and street scene.
A proposal that increases parking provision along with habitable accommodation