Rear Extension Cost
Guide to adding a rear extension with pricing and general advice
Building an extension will improve any home by creating extra living space, which will also add value to the property and make it easier to sell. If your existing home no longer meets your needs, building an extension is almost always a wise investment and great way of gaining the extra space you need. There are many reasons why people decide to add an extension, but the most popular is simply the growth of the family requiring additional bedrooms and living space. The lounge, kitchen and main bedroom are the most popular rooms to extend, particularly if they have a rear facing outer wall which can easily be knocked down and a new wall can be erected further into the rear garden. If you need more than one room then a multi-room or even double storey extension can add a considerable amount of space for growing families.
Cost for building a house extension to the rear
Things to consider when building a rear extension
For the building of a traditional extension to the rear of your property, you will need a reputable builder who has experience in building extensions and can work to the plans that you, or your architect, have drawn up. You should consider using an architect if possible to draw up the plans as they can also assist with any planning permission applications required for your extension and advise you on how best to approach the extension. Even if you do not require a planning permission application for your extension project, don’t start work without talking to your neighbours. In most cases, if you apologise in advance for any mess or noise, then you are much less likely to be involved in a dispute. With any building project, there are often foreseen expenses involved, so it’s always a good idea to have contingency funds available of at least 15% of the expected build cost.
Before you decide to go ahead with an extension, make sure to let your insurance company know about the changes being made, such as adding rooms and any work that involves walls being knocked down, floors being taken up or electrics being changed. If your insurer isn’t told in advance about your plans, the home insurance policy may be invalidated.
Be prudent when spending on an extension. Even though most extensions add value to the property, it doesn’t necessarily mean you’ll always get it back. The actual value added depends on where you are in the country, it’s always worth speaking to a local estate agent to a local estate agent to get a rough valuation of how much value they think an extension will add. Be careful that you do not spend so much money that you overshoot the price ceiling in your area.
Doing it Yourself
Be very careful about tackling a rear extension as a DIY project. But if you have the necessary skills and experience, plus the time required, then doing at least some of the work yourself can save a lot of money and can even be fun. Unless you are a builder, you will probably want to stick with the “wet trades” work (digging foundations, mixing and laying concrete etc) as these are the easier jobs.
It is best in most cases to leave the laying bricks and blocks, plus building in the windows and doors to the professionals. The lintels and cavity trays and perhaps tiling the roof may be too much for most amateurs too. But once the walls and roof are up, cutting joists, laying decking and fixing plasterboard is pretty straightforward. Even most modern plumbing is fairly easy if using plastic push-fit systems, so minor plumbing work like adding a new sink can be done by the average DIY enthusiast. The decoration is another area where the DIY person can save money, but plastering is probably best left to the professional’s unless you have previous experience and are sure you can achieve a good finish.
One area which you should definitely hand over to skilled tradesmen is the electrics. Unless the works are very minor and do not require a new circuit, then home electrical work must be done by a competent person able to issue a self-certification certificate.
Rear extension Checklist
- Many councils allow for extensions under what is called permitted development
- Architects can help you with the design and technical drawings of your extension
- All extensions will have to adhere to strict Building Regulations, which are completely separate from Planning Permission
- You should be prepared for a significant amount of disruption including dust and noise during the extension process
Hiring a Tradesman Checklist
- Always get at least 2 quotes before hiring.
- Never pay the full amount upfront.
- Get the quote in writing.
- For any payment you make, always get a receipt.
- On more expensive jobs, ask for references.
- Check if the tradesman is a member of any trades associations.
- Make sure the tradesman has public liability insurance.
Do I need planning permission for a rear extension?
If I need planning permission, how long will it take?
How much will my rear extension cost?
Do I need special home insurance?
Ground floor kitchen shower extension.
Submitted by Sam
Hi there, planning to build a new bedroom top of the garage.
Submitted by Wasim
Single story kitchen diner rear extension, the same width of the house. Currently, 1 small extension/sunroom that is not keyed into the house which needs knocking out which will be replaced by this extension and remove the wall from kitchen to sunroom. Wanting to be done asap and completed within a ...
Submitted by Daisy
We have had an L-shaped extension done onto our house. It has been roofed and glazed. The builder did not finish the walls up to roof height, and left the job as he was offered a contract in London, and said his mate would come around and finish the job. His mate came around and fitted barge-boards ...
Submitted by Rick
Conversion of a conservatory to a dining room with a bit more extension to sideways. Building plan in hand.