House extensions are a common sight in London. Most of the house owners at some point in their lifetime plan to increase the size of their homes depending on the needs of their growing family to get in that extra space without relocating. To help navigate through your house extension project we have put together some insights based on our experience in building extensions and loft conversions in and around North and North West London.

How much does a house extension cost in North London? Things to know before you start a house extension. Ways to keep your house extension costs down.

How much does a house extension cost in North London?

The key question every homeowner asks to themselves before starting a house extension job is how much does it cost? To answer this question – there are various points to consider.

  • How much is the new extension area?
  • What quality build are you looking for – medium spec, high spec, etc.?
  • How involved would you be during the build?

For a standard rear single storey extension, price per sq.m for a medium to high spec house extension project in North and North West London ranges from £1,600 to £2,000 per sq.m excluding VAT.

Things to know before you start a house extension.

  • Will the house extension add any value to the property? As a homeowner its always advisable to see if adding the extension adds the same or higher value than the actual cost of the extension.
  • Choose a right designer/architect to design your home.
  • Will you be living on site during the build phase with the disruption, dust, etc or you plan to move out in a temporary accommodation?
  • Building regulations – These are minimum standards set by the government to design and construct a property. Your house extension will need to comply to it. You need notify a local authority building control or Approved Inspector before starting any build on site.
  • If the extension is build on a near a sewer – you will need a Build Over Agreement from the water authority in charge of your area
  • Comply with Party Wall Act if the works involve digging for foundations within 3 meters of the neighbours boundary.
  • Make sure the builders have required insurances in place and you have informed your insurance company regarding the house extension before starting the build
  • Will the existing boiler and fusebox need replacing as the existing boiler output might not be enough to heat up the new radiators or the new fusebox will need updating based on latest regulations.
  • Make sure you have factored in the VAT for the build and if there is any VAT relief you can claim.
  • Allow a contingency of around 10-15%

Ways to keep your house extension costs down

  • Choosing a right designer/architect and getting detailed plans with all required specifications makes it easier for builders to quote exactly what is required and as a homeowner it gets easier for you to compare all quotes received.
  • Allow enough time to do all the paperwork as it takes upto 8 weeks or more to get the planning permission if needed and can take few weeks to get the party wall paperwork in place.
  • Get a detailed quote from the builder with a breakdown of all items so it gets easier to add or deduct works based on the unit price allowed for in the original quote.
  • Sign a building contract (JCT or similar) with the complete scope of works, price agreed and the work duration of the project.
  • Moving out of the property during the build phase can speed up the construction process and reduce the work duration and can save you the stress of living on a construction site.

Eternal Design and Build has completed many extension projects in and around North and North West London. Our works include everything from extensions, loft conversions, structural alterations to complete house refurbishments. We believe in building trust with quality works. Our team of highly skilled and qualified employees hold a wealth of experience to provide you with exceptional standards.

Are you considering a house extension done in London? Eternal Design and Build Ltd is a one stop solution for all your building needs. Contact us today for a free no-obligation quote.