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Building a house extension is a simple process but there are some key factors you have to consider in order to make the experience enjoyable and safe from any pitfalls.

Step 1

  • Where are you looking to place the extension.
  • Is it possible to build the extension where you would like it located.
  • Is there a better option that will mean less preparation such as moving drains etc.
  • Will an extension put value on to your property.
  • What is the value of your property, eg it doesn’t make sense to put a £30k extension onto a property that’s worth £70k you would be better moving home.

Step 2

  • What permissions are required. Semi detached/terraced permitted development meaning you don’t need planning permission you can project 3m from your property. Detached properties can project upto 4m.
  • How much will an architect cost. This depends on the size of the extension but allow for roughly £1000
  • How should I set my budget? Take the value of your property and divide this amount by the total number of rooms in the house, lounge, kitchen and bathrooms etc. This gives you the average cost of a room in your property this is a good starting budget then add on any extras such as kitchen etc.
  • What other hidden costs are there? Building Regs are roughly £500 Planning permissions are roughly £250.

Step 3

  • Design of the extension. Option 1 contemporary so it is modern and allows you to get creative with the design or Option 2 brick match, window match and roof match so the extension looks like its always been there and the property has never been extended.
  • Internal extras. Read our kitchen extension link to work out the cost of a kitchen on top of the extension cost.
  • Most builders quotes, and most prices quoted online, are for what we call a shell. This simply means the extension is finished to building regulations but does not include any extras such as flooring, decoration, kitchens or specialised lighting etc.
  • Problems always arise when your budget for your extension is low and you expect all the extras to fall within that budget as well.
  • Always ask your builder for price freeze to ensure the price agreed is all you pay.
  • Ensure your builder offers you whats called a full scope of works. This should be done electronically and allow you to electronically sign it and return so you both have proof of what is or is not included to avoid any issues further down the line.