Building on a budget: Top tips to cut your extension costs
It can be challenging creating your dream extension while sticking to a tight budget. But there is no need for spending to spiral out of control or nasty surprises. We’ve asked two Chartered Architects for their top tips on how to get best value for money without compromising on quality.
Get professional advice
Time spent planning your project can save a lot of money and heartache further down the line, said architect Chris Fry, of Pro Vision. “The first bit of homework is to set down your aspirations or wishes and what you want to achieve. List your top priorities or must-haves as opposed to nice-to-haves. It’s important to understand what is achievable with the money available. This is where an architect can be helpful.”
A skilled architect will also come up with alternative design solutions you or your builder may never have thought of. Perhaps you can achieve your aims without the cost of building a new extension. For example, by remodelling your existing home - knocking down internal walls or converting a loft or garage into useful living space at a fraction of the cost.
Choose a simple design
Keep the design of your extension simple. Stick to square and rectangular shape layouts. Avoid odd shapes if you want to cut costs. Curves and L-shapes are expensive to build. The simple design of a gable or pitched roof makes it easy to construct but a hip roof (with slopes on all four sides) “takes more labour and a curved roof is ten times trickier again,” said architect Laurence Wright, of BBD Architects.
Single-storey extensions are simpler to build and less substantial than two-storey; so cheaper. Choose standard-sized windows and doors which are easier to install and more affordable. If possible, avoid building near drains or other buried services as complicated groundworks will increase costs.
Stick to the plan
After you have agreed a final design, try not to change your mind. Alterations and delays will incur extra charges which quickly mount up. Careful planning at the design stage, right down to position of light fittings and electrical outlets, will save you money on making expensive revisions after the build has started. “Spend time on the design to make sure you’ve got it nailed,” said Laurence. Visualise the project – 3D software can help. Work out the windows, door openings, ceiling heights and floor levels between rooms. Do you want underfloor heating? Be decisive. If you do have to alter your plans, always agree the price up front (and in writing) with your builder.
Focus on building materials
It can be expensive and frustrating to build a new kitchen extension only to find your granite worktop is damaging the floor or there isn’t electrical wiring in a position that can accommodate the hob, said Chris. When extending a house, don’t just focus on the decorative side of things. Ensure services, such as electrics and plumbing, are in the right place and it’s structurally sound. Invest in high quality building materials – glossy new kitchen cabinets can be added later. Bricks and roof tiles are an intrinsic part of the design. A helpful architect can help you source building materials within your budget.
Be your own project manager
Builders typically add between 15 to 25 per cent to the total cost of labour and materials to pay for their time managing a project. You can save large sums by taking on the role of building contractor yourself. This means hiring tradespeople, such as electrician and plumber, co-ordinating their work, buying materials, liaising with your architect and the local authority, hiring scaffolding and skips. It is time consuming and your extension is likely to take a lot longer to finish but the savings can be substantial. The Housebuilder’s Bible is a useful step-by-step guide.
Muck in the simpler jobs
If you don’t have the time or confidence to be your own project manager, you can still save money by carrying out some of the simpler tasks. For example, once the extension is built, decorating it yourself will reduce the overall bill. Sweeping up the site at the end of each day can be another way of saving money. But for the drawings, plans, electrics, plumbing, bricklaying, plastering and roofing, it’s always best to hire a professional to avoid expensive mistakes.
Source your own materials
It is standard practice for builders to mark up the materials they buy on behalf of a client. You can buy materials direct from a builders’ merchant and hire skips yourself to save money. But it may be more cost-effective to take advantage of your builder’s trade discounts rather than buy your own materials. “Most builders have trade accounts and get significant discounts, so even with the mark-up, it’s likely to be cheaper,” said Laurence.
Save on VAT
Many extensions will incur VAT at 20% on labour, materials and professional services. One way to save on your build costs is to hire self-employed tradespeople and professionals with a turnover less than the VAT registration threshold (£85,000 in 2019/2020). This can cut the cost of your build by thousands of pounds.
Some extensions are eligible for VAT relief, such as extending a building that has been empty for at least two years. To qualify you must use a VAT-registered builder as you can’t reclaim the tax yourself.
Save on professional fees.
Architect fees typically add about 15% to the cost of a project. If you have a clear idea of what you want or it’s a simple, low-cost build, an architect may not be necessary. An architectural technician or chartered surveyor can provide the detailed drawings required for Building Regulations consent at a fixed price. The advantage of hiring a fully qualified architect, however, is you will pretty much always end up with a better design. Look for one-man band architects with a track record of designing low-cost projects as their fees will be lower than bigger practices.
Save on planning fees
If your extension comes under permitted development rights, no planning application is required. This will save paying the local planning authority a fee of £206. But you may still want to apply for a Lawful Development Certificate (LDC) to show the extension is legally built. This paperwork is useful when it comes to selling your home. The LDC is 50% of the cost of a planning application, or £103, so total savings will be minimal. Even if you don’t need planning permission, your extension must comply with building regulations and those fees can’t be avoided.
Be a savvy shopper
Black Friday deals and buying end-of-the line can save a fortune, especially for tiles, carpets and large appliances. With careful planning, you can cut costs without compromising on quality. Another way to save money is to avoid designer brand kitchens. Check out your local DIY stores and building trade suppliers, such as Howdens. You can have a kitchen tailored to your individual requirements without the big brand price tag. Be creative with your lighting too. Shop online for pendant lights and LED fittings that look as attractive as expensive fittings.
Consider how you can re-use existing materials rather than throwing them on a skip. Bricks, roof tiles, old floorboards, fire surrounds and kitchen units can all be cleaned up and reused or sold. Existing kitchen cupboards can be repurposed for the new utility room, for example. Sell or trade what you can’t use to scrap yards. Reducing the amount of building waste means lower skip hire charges.
Bigger isn’t always better. Balance the amount of money you are willing to spend on your extension with the value it will add to your home. Before you extend, talk to a trusted local estate agent about the impact it will have on the value of your home. It may make more financial sense to move rather than improve.
Laurence said: “What is your street value? If you bought your house for £300,000 and the most expensive property on the street sold for £400,000, I would think twice before building a two-storey extension costing £150,000. In the longer term, you may recoup your investment, but if you have to sell in a year or two you could stand to lose money.”
Nobody wants to spend more than necessary on building an extension. These expert tips should help you add valuable extra living space as affordably as possible.