[ Planning an extension ]
Riba-chartered architect Jillian Mitchell, of Project Logistics Architecture, on the rules and regulations you need to know before you start a project
* Even the simplest extension
can have an undesirable effect on your home, perhaps by cutting out natural light or creating awkward routes from one room to the next. Unless your design is very small, it’s worth investing in an architect who will submit a planning application on your behalf and ensure that supporting information is available in time. If you live in a conservation area or a listed building, they may also need to prepare a Design and Access Statement as well as a Heritage Statement, both detailing the likely impact of your plans.
* Permitted development rules
can be useful if you want to make minor additions to your home without planning permission, but there are lots of exceptions. For anything on a larger scale, you’ll need a planning application. Visit planningportal.co.uk for more information on this.
* Terraced properties
have more limitations on being extended as they are likely to impact neighbours. A Party Wall Agreement is needed for any building work that involves a wall shared with next door, or that come within three metres of it. The rules are complex and you’ll be responsible for all of the costs, so it’s worth researching thoroughly.
* When it comes to the issue
of whether an extension overlooks neighbouring homes, balconies and sidefacing windows on upper floors need to be considered sensitively. Even if you won’t see into your neighbour’s property, there may be a perception of being overlooked, which planners will give weight to when considering your design.
* Basements present several challenges and should be carefully designed to avoid progressive damage to a building’s fabric. Excavating a new basement requires a structural engineer and should not be undertaken lightly – the consequences of structural failure can affect your neighbour’s property as much as your own. Excluding damp is vital: this can be done by either keeping water on the outside of the structure, or with internal waterproof membranes that channel water away through a specially designed cavity.