extending your home

10 things to consider before extending your home

So you love your home and don’t want to move, but you feel you need more space. ‘What about an extension?’ is the thought that niggles away at you until you decide to look at it in more detail.

There are certainly a few pros and cons of an extension, ultimately it will come to three things; how much space you really need, how you want to use the space and how much you’re willing and prepared to spend.

For example, if it is a larger kitchen that you’re after, maybe with a dining area and a little extra living space, or an additional study or guest room, having an extension built would seem like a good idea. The benefit of having an extension to your house is that you can choose the size and shape to suit the function you have in mind.  You may be looking to extend to the back of your house, or the side or to go up into the loft space, so then design issues start to feature at an early stage.

The size, location and even things like the soil conditions will affect the overall cost of the project. A rule of thumb is to allow around £2,000 per square metre so depending on the size, a single storey extension can range between £10,000 – £100,000, quite a variation. And whilst it will add value to your home, it may take a good few years for the costs to be fully realised.

Still fancy taking this project on? Here’s a list of 10 points that you should give some thought to.

  1. Do you need planning permission?

You need to make sure you have the correct planning permission. Whilst not all extensions require planning permission in some cases (such as listed buildings or height restrictions), your plans could be halted before they start, or worse still, once they have started. Under ‘Permitted Development Rights’ in certain circumstances you can begin building without telling your local authority. You can check the criteria on your local council’s website on the Gov.uk website. A good idea is to pay a visit to your local planning office to ask them if what you have in mind will require planning authorisation.

Do also bear in mind a thought for your neighbours. Even if planning permission is granted, it is courteous to at least inform your neighbours about your building plans.

  1. Choose a suitably experienced architect/designer/engineer

It is important to find an architect/designer/engineer with expertise in the type of extension you’re planning together with experience of your location. Like builders, architects and home designers do not need to be registered with any particular organisation or agency. However, choosing one that is affiliated with a reputable architectural body is a prudent step. Among the main bodies are the Royal Institution of Chartered Surveyors (RICS) and the Chartered Institute of Architectural Technologists (CIAT).

A good architect/designer will help you to design your extension in such a way that it merges seamlessly with the main part of the house. This does not necessarily mean matching materials exactly but blends the different parts of the house to show how it has evolved to suit a new purpose, a new homeowners requirements, such as growing family.

You may wish to consider architectural technologists as well as architects. Architectural technologists are those who studied architecture but have not completed all the applicable exams. For smaller extensions, these professionals might be suitable – and may cost less than a fully-fledged architect.

Whomsoever you choose to work with, do make sure they carry sufficient professional indemnity insurance (PII). And be aware that if you carry out the designing yourself, you will need your own PII.

  1. Make sure you meet Building Regulations

Building Regulations are laid out by parliament and cover aspects of a dwelling such as fire safety, insulation, drainage and access.

You can either submit a Full Plan Submission or a Building Notice. The former requires more detailed advance planning but could reduce the chances of you contravening any regulations. A Building Notice, by contrast, is the riskier (and potentially costlier) of the two, since you may only find out you have a compliance issue after work has been done.

  1. Building site constraints

An important early consideration is a site itself. If you have a complex site, this may affect the design, construction, timescale and of course costs. The kind of issues that you will need to factor into your plans include any surrounding trees or outbuildings and ease of access to the property. A terrace house and/or lack of a driveway may make it difficult to manoeuvre tools and materials so you should plan ahead so work isn’t delayed. In addition, you should consider the effect of structural changes on the site and if the soil type demands a specific building technique or material. Plus if you’re moving drainage, pipework, gas meters and so on this will require extra planning and cost.

  1. Find a reliable builder

A fundamental part of any building project is to make sure you will be working with a reputable, reliable builder whom you get on with. Personal recommendations will go a long way in can ease any worries over skills, experience or character. You will be in contact for a long time so it will also be important to get on with your builder on a personal basis.

In the interests of continuity and cost savings, it will be beneficial to work with a group of tradespeople who collectively cover a range of skills. For example, having access to two people who are skilled electricians could eliminate any downtime caused by non-availability of a particular electrician. When hiring tradesmen, remember you will be responsible for things like keeping the site tidy and taking out applicable insurance.

  1. Get several quotes

Prices for extension projects from different builders can vary enormously, so it is wise to get between 3-5 quotes. That way you can get a feel for what the market rate is, as well as see who you get on with the most or feel is most capable of the job. After all, they are going to be around for a while!

But don’t confuse an estimate with a quote. Usually, when builders, surveyors, architects and so on first visit a property they’ll give you an estimate. This is a good starting point but it can differ from an actual quote. You’ll receive an actual quote in writing usually after everyone has gone away and done some thorough calculations. This is your quote and is what the project should cost.

A builder should be able to give you a detailed quotation if you have provided sufficient information. Avoid day work rates as they can push costs up. If VAT is to be added to the bill, make sure the VAT registration number is detailed on the receipt.

It’s worth having someone else with you when you get quotes, as another opinion on price, timeframes and personalities can be very helpful. Try to find someone who has been through the process before. Plus you’ll also feel less pressured to make a decision there and then if you have someone else with you whom you trust.

  1. Financing your extension project

If you need to borrow funds to finance your extension project, you might consider a personal loan – usually available up to the value of £25,000. If you need more cash than this, consider remortgaging your home or taking out a secured loan to get the required capital.

In terms of budgeting for the project, it is a good idea to add a contingency of 10% to allow for time delays and overruns, additional resources and materials, changes in your specification, finishings and fittings etc.

Do work out the outgoings at each stage of the project. In general, builders will take payments at different stages of the building process. Costly items should be purchased in your name, in case the builder goes out of business.

An architect will require payment as they work. An accurate quotation is important in order to get a good idea of the final cost.

  1. Decide whether to move out during construction

Given the disruption and noise associated with extension building work, you may decide to move out for the duration. Moving out and finding temporary accommodation can be one of the most hassle-free options, but that’s not always possible. If you do decide to stay on the property it is likely you will need to put up with dust, no kitchen and occasional breaks to the power and water.

Some decide to move into a caravan in the garden – although this may not be practical for large families. Renting rooms nearby is a costlier alternative.

Moving overseas for the duration of the work and leaving your builder unsupervised is however not recommended unless you have a very good relationship with them and/or a good friend to oversee the project.

  1. New kitchen or bathroom?

If you are looking to incorporate a new kitchen or bathroom in your extension, you will need to account for additional services, with the associated costs. Whilst the design does get a little more complex, a bit of careful planning will pay of considerably later.

Plans and permission need to account for plumbing and then the plumbing actually needs to be installed. For a bathroom, you’ll need to think about what you actually want from the bathroom (toilet, shower, bath). It’s worth noting that, from a planning permission point of view, you can have showers and WCs anywhere.

A kitchen will cost more than a bathroom, by around £10,000. But it does depend on whether you want a low/mid-range kitchen or something more high end. So it can all depend on how fancy you want your kitchen to be.

Because both kitchen and bathroom extensions will vary in your tastes, it’s best to use a house extension calculator to figure out your ideal extension. You must also plan for additional heating and electrical circuits and work out if your existing boiler is able to cope with the additional demand of the extension.

  1. Finishings and fittings

So you’re nearly, there, you have the shell of the extension completed, with all the services and you can see the finishing tape in sight. This is when it is tempting, as with the kitchen and bathroom extensions, to start to spend a little more on those important extras, such as tiling and flooring, that can sometimes add up quite quickly to nudge you over your overall budget.

If you’re happy with simple painted walls, carpet or engineered wood floors, and standard lightings and electronics then your costs will be kept low. But higher end stuff, like tiling, fitted joinery, bespoke flooring and so on costs will rise. Make sure you account for this in your extension cost calculation. Just make sure you’re getting what you want and don’t let anyone sell you the most luxurious finishings if you’re happy with a simple finish.

And once the building work is complete, do make sure you ask your builder for all the necessary certification, including building control certificates, electrical and gas safe certification. Without these, it will be harder to sell your property later should you wish to.

We hope you’ve found our short guide useful. Our teams at FABRICO have successfully completed hundreds of similar projects, so we have the If you would like to know more, feel free to have a browse through our facebook page or website or click here to contact us.