10 things you need to consider before extending your home

Deciding that you and your family have outgrown your house is easy. Deciding to actually do an extension, not so much. Here are 10 things you should consider before making a decision on whether you can take on an extension or not:

1. Budget

There are numerous online calculators that can give you a rough idea of the construction cost of your project. But there are some hidden costs that you should take into account as they can add up:

Measured survey

Architect’s fee

Structural engineer’s fee

Party Wall Surveyor’s fee, if your house is a semi-detached or terraced

Other consultants’ fees, depending on the property there may be needed a number of consultants such as Arboriculturist, Transport Consultant etc [you can ask your architect to list these]

Planning application fee

Building Regulation Approval fee


Self-build insurance

Thames Water Agreement

Waste removal

Landscape/Garden works

2. Adding value

Any works done to a property can add value, or not. It is very important to understand that not all alterations or extensions actually increase the selling price of your house. Extensions and loft conversions are expensive, but in many cases they can reward your investment when it comes to selling.

How much value you add will depend on the quality of the work, if there are any additional rooms created, and what is the maximum price in your area. This means that there is a limit on how much a property can sell. It is a good idea to talk with your local estate agents to see for what price similar homes with extensions are selling at around you.