Building an Extension? – What to Consider

With rapidly spiralling house prices forcing more people to stick with their current property for the time being, a number of homeowners are choosing to extend their existing property in order to gain extra space without having to sell up. Although the cost of building an extension can be significant, it is a sure-fire way to add value to your home and will serve those looking to move away in a few years time just as well as those who are setting up for the long haul.

As with any major project, there are a lot of factors that need to be carefully considered before any work on an extension can be undertaken. From initial designs to planning applications, supplies to labour costs, each stage of the process has the potential to cause major disruptions to the project if it is not thought through before hand.

Design and planning

It is important to keep in mind the ‘look and feel’ of your existing property when designing an extension. Try to match the most prominent features, such as the roof, with those of the existing building and use similar materials where possible to ensure a sense of continuity. It is also a good idea to make sure that any new doors and windows line up with existing fixtures.

Think about the neighbours

During the planning application process, neighbours will be able to air any misgivings regarding your proposed extension, so it is a good idea to ensure that the extension will blend in with the other properties on the street. Getting neighbours involved during the initial stages of design can save a lot of time and money later down the line if they do have any objections or concerns. Even if you are legally entitled to make changes that they oppose, it could be better to compromise than make potentially life-long enemies.

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.

Planning permission

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.

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