House Extension, a way to add more space in your house


If you are wondering how you can add more space to your house without having to move, an extension is a simple solution for you. No matter what you need, a spacious kitchen or some extra space for a living room, extending your house may be the best idea for you. Before you start working on an extension, you must find out the answers to a few questions. For example, how much will an extension cost? How to get planning permission for extensions? How far can you extend? Along with a clear understanding of these topics, you need to have a clear vision of what you want to do with the extended part of your property.

Things to consider before building an extension

You should consider the following things before you start for an extension in your building:

  • Shared walls
  • Easy access to the site
  • A check on current services
  • Insurance
  • Soil condition
  • Surrounding trees
  • History of flooding
  • Rights of way

By having a check of these conditions, you can ascertain what documents you may need to apply for planning permission.We also recommend that you check if any of your neighbours have done extensions in their properties. Having other extensions in the area increases the chance of obtaining planning permission without hassle.

Planning Permission for extensions

In many cases, extensions to a building fall under permitted development rights. So, if you are wishing for a small extension, you probably do not need a planning application. Under permitted development, some of the rules you can follow to avoid planning application:

  • A maximum of half the area of the house can be covered by the extension.
  • No extension can be done in the front of the house or in the side of the house that fronts the highway.
  • Extensions cannot be higher than the highest part of the roof.
  • Single storey rear extension must not extend beyond 8 metres for a detached house and 6 metres for any other houses.
  • More than one storeyextensions must not extend more than 3 metres.
  • Materials have to be similar to appearance to the existing house.
  • Two- storey extension has to be away from the original boundary for at least 7 metres.
  • No verandas, balconies or raised platforms.

For more information on permitted developments for house extensions, you can visit the government’s planning portal (

You need to keep in mind that, houses in the following areas have more restricted rules for permitted development:

  • conservation area
  • area of outstanding natural beauty
  • the area specified for enhancement and protection
  • the Broads
  • a National Park
  • a World Heritage Site

Permitted development rules that applies for regular houses also do not apply for flats and maisonettes, converted houses and other buildings.

For the developments under permitted developments, we would still recommend you to apply for a Lawful Development Certificate, which will confirm that the development is under permitted development. But, if you want any changes that do not fall under permitted development, you will need to apply for planning permission before starting works. You can apply for planning permission to your local council online. It will cost around £206.

Building regulations of Extensions

After having the planning permission, you need to have a plan for what goes where. This is where building regulations come. This will ensure the safety of the building and the people living in it. You have to make an application to the building control board to make sure that the plan you have for your extension complies will all the building regulations rules.

You can submit for building regulations approval in two ways.

  • Full Plan: This way, you will have to submit all the details with drawings of your plan to the building control. A building control inspector will visit your property after completion of each stage of construction.
  • Building notice: It is a statement that you can submit to the council 48 hours prior to the construction, stating that you will be complying with the building regulations. An inspector will inspect each stage of construction and will advise you regarding any issues.

A full plan can be helpful during the construction, as it has all the drawings and measurements necessary. Building Regulation approval is compulsory regardless you need planning approval or it is permitted development.

How much can a building Extension cost?

Depending on the size, specification, and location, the cost for building development varies.  A basic quality extension will cost less than the best quality that is available.  A basic quality extension may cost something from £1,000 to £1,600 per square metre. While the best quality can cost around £ 2,000 per square metre or more. A two storey extension does not cost much more than a single storey one, only because there are only a few extra things like walls and floor joists. Also, you have to keep VAT in mind while you plan for an extension.

1 Comment

  1. author What is Outline Planning? – KPCL Architecture posted on August 23rd 2019. 11:27 am

    […] outline application is usually acceptable for a new building, for an alteration or an extension of the building. This type of application is made to see if the application is valid in principle without spending […]