But undertaking major work like this requires a great deal of thought and many homeowners simply don't know where to start.
Building and extension: Where to startThe first thing to establish when building an extension is what your needs are.
Extensions can come in various forms and knowing where your need for space lies will help you decide what kind of extension will work for you - or even if another form of additional space would work better.
Here, we'll look at a checklist of things to consider before starting work on an extension, before outlining the key stages of building an extension.
Will an extension add value?Ask yourself right from the start whether your plans for an extension will add value to your home if and when you come to sell it.
Sometimes properties in a certain location have a ceiling price, so it can be worth speaking to your local estate agent to get an idea how much value major work might add to your home.
Do you need planning permission for an extension?The question of planning permission is usually the one that sends fear searing through the veins of homeowners considering an extension.
But it really doesn't need to.
In fact, most extensions don't require planning permission at all.
But it does pay to know what you can and can't do under 'permitted development' before you start planning your dream extension project.
Under permitted development, you can do the following without requiring planning permission:
* Extend from the rear of your detached property by eight metres for a single-storey extension or three metres for a double-storey extension
* If your property is terraced or semi-detached, you can extend to six metres to the rear of the property for a single-storey extension
* Build a single-storey extension no higher than four metres to the eaves and the overall height no higher than the existing property
* Build a two-storey extension as long as it is no closer than seven metres to the rear boundary
Any extension must not take up more than half of the original land around the property without planning permission and extensions should be built with similar materials to the original property.
There may be different rules for properties in conservation areas or if a building is listed.
Building regulationsWhile you may not need planning permission to build your extension if it falls under permitted development rights, you will need to comply with building regulations.
That means whoever builds you extension must be either backed by an official governing body, such as FENSA for window fitters and Gas Safe for gas engineers) or be able to liaise with the local council who will certify the work.
Failing to comply with building regulations means you could be forced to remove your extension at great cost and inconvenience, as well as being unable to sell your home in the meantime.
Your buildings insuranceBefore breaking ground on your extension, contact your buildings insurance provider to let them know about your project.
As the extension will almost certainly increase the rebuilding cost of your property should it be destroyed by fire or flood, your buildings insurance policy will need updating.
Your existing policy may cover you, but it's always worth checking and being prepared to pay an increased premium for any additional cover.
Neighbour disputesOne of the most common causes of friction between neighbours can be building work.
Should you need planning permission for your extension, the local authority will contact your neighbours for their views.
This is where letting them know before the planners do can pay off.
Outline exactly what you're doing and try to provide peace of mind if they have any concerns.
Not only will this keep relations positive, it could also mean they are less likely to oppose the plans with the local authority.
The Party Wall ActYou may require a Party Wall agreement with your neighbour(s) if your property is terraced or semi-detached.
Party walls are shared walls that divide the homes of separate owners, but also include garden walls built over boundaries and excavation work conducted within a certain distance of a neighbouring property.
A Party Wall agreement may be needed if your extension requires ground work or the use of steel supports that could affect a neighbouring property.
Stages of building an extension
Of course, there is no legal requirement to use an architect to design your extension.
But doing so can mean a better result.
Architects can make better use of space when designing your extension, so if you have specific needs and goals you want to achieve from the additional space, it could pay to have a professional in your corner.
Picking a tradesperson to do the work
This is arguably the most important decision you'll make around your extension project.
Start by speaking to friends and family for recommendations. Even if they haven't used a particular builder themselves, they may be able to put you in touch with someone they know who has.
There's no better confirmation of a tradesperson's work than work of mouth, even in this digital age where reviews and comments are readily available online.
Get quotes from at least five companies and match them up with your budget for the work.
If you're particularly drawn to a more expensive quote based on a builder's previous work or great reviews, only stretch your budget if you can genuinely afford to do so.
And remember: Having a small fighting fund set aside can really help, because any major building work usually ends up costing more than you bargained for.
Although almost all extensions are different in some way, most will follow a similar process through the construction process.
Here's what you can expect:
* Site security, storage, access and risk assessment
* Demolition (if any), groundworks and drainage
* Erection of walls and roof
* Window / door fitting
* Fitting of downpipes and drainage connections
* External finishing (rendering, painting)
* Internal renovation work
* Electrical / gas / plumbing fit-out
* Flooring and internal decoration