Hiring an architect
People can visit an architect for advice on what is and is not feasible with the space at their disposal, once they have an idea of what they want their new extension to entail. Qualified architects will also be able to provide extension advice, on issues concerning planning permission and any local factors that may influence the modifications that can be made to a property, as well as drawing up detailed specifications. Many may offer to oversee the building of the extension as project manager, for an additional cost.
For most people extending a property, a successful application for planning permission will be necessary before any work can be undertaken. Planning seeks to control the way that neighbourhoods, towns and cities are developed, focusing on the way that land is used, the appearance of buildings, landscaping considerations, road access and the impact that a development will have on the environment. You will definitely need planning permission if:
- The proposed extension is higher than the highest part of your original roof
- Any part of the proposed extension is over four metres high and within two metres of your property boundaries
- The ground area covered by the proposed extension covers more than half of the total property area (excluding ground covered by the original building)
- The total volume of original property is increased by more than 115 cubic metres (volume is calculated using the external dimensions of the structure: length x breadth x height)
- The total volume of original property is increased by more than 10% (or 50 cubic metres, whichever is greatest) for terraced houses, or any property in a conservation area, a national park or the Broads.
The planning process
Once the council has received your plans, it will place them on the Planning Register for public viewing and notify neighbours. A committee appointed by the local council will then make a decision or appoint a senior planning officer to make one for them. The process can take up to eight weeks, and if permission is granted, planned works must be completed within five years.
If permission is denied, plans can be amended to take account of any problems raised by the council, then resubmitted within 12 months without any further charge. Appeals can be lodged within three months of the council’s decision. Those who fail to apply for planning permission before building an extension may face heavy fines and be required by law to demolish any new building work.
More information regarding planning permission can be obtained via local authorities, or by visiting the Government’s Planning Portal website. Many architects offer to take care of the planning application process and any appeals/amendments for an additional fee. Alternatively, homeowners can seek the services of a specialist planning consultant.