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7 tips to keep house extension costs down

If you're building, converting or extending your home, these are our tried-and-tested tips for getting the most out of your budget, without cutting corners.

5 min read

There are two simple tips that will always save you money during a building project: don’t cut corners and do your homework.

Here are 7 things you can do to ensure that you’re making value-adding decisions (without having to settle for less).

Make pricing your project as easy as possible

When it comes to extending your home, you want to make sure the professionals you engage with can provide accurate costs and price plans up front. Naturally, to avoid unexpected costs popping up, you want to make their job as easy as possible.

Two ways you can make pricing easier is by investing in a high-quality measured survey at the start of your project, as well as a comprehensive building regulations package before you begin construction.

Measured survey

Measured surveys form the backbone of any project. By measuring up your home as it stands today, your surveyor will produce the details needed to create a set of existing drawings. These architectural drawings will then be used by your architect, planning authority, structural engineer, contractor, and other residential specialists.

Because they’re so important for so many stages of your home extension, you want to make sure they’re as accurate as possible. If not, you may have to redo certain stages, re-evaluate your home, or even face additional costs during the construction process - this is both time consuming and expensive!

The moral of the story? Invest is a quality surveying service, such as those who utilise laser scanners in the process.

Learn more: What kind of survey do I need?

Building regulations

While legally you’re not required to commission a building regulations package, they do provide a lot of benefits for a project. Namely, the highly detailed technical drawings they produce will make it much easier for any potential contractor to price up the work involved.

What’s more, without this package, you’re relying on a contractor to fill in the technical gaps and this can both put your home at risk and also your finances, as you’ll be liable for any repairs and unforeseen building requirements on site.

2. Check your contract and break down your quote

  • Never start building an extension without a tight contract, such as a JCT. If anything changes during your project (and it probably will), this gives you a legal way to keep a handle on inflating costs.
  • Make sure that your builder provides you a fully costed quote, so you understand the price of each element. That way, if you need more of anything, you can reference the original price per unit.
  • Don’t skimp on exploratory work - from CCTV surveys to checking the quality of the roof and foundations. Anything you can do to reduce surprises down the line will help you to budget accurately from the start.

Learn more: Importance of ‘connecting’ with the right professionals

3. Compare suppliers

At every stage of your project - from finding an architect to sourcing a builder - you should be soliciting 4-6 quotes from different suppliers.

However, remember that cheaper isn’t always better: it’s about finding people who are offering you value, quality and trust.

It’s often possible to save money by sourcing your own contractors, rather than allowing one builder to handle the entire contract. However, you’ll need to be extra careful that everyone has a good idea of their responsibilities and how they interact, or mistakes can end up adding time and money in the long run.

Learn more: “I chose the cheapest contractor quotes and paid for it!”

4. Consider a project manager

No matter whether you're building a two-storey rear extension with a renovated kitchen or simply removing your conservatory, a project manager is always important to consider.

It’s like the old saying, “you have to spend money to make money”. For a £50k project, it may seem steep to spend £5k on a project manager but you may make considerable savings as a result of keeping your extension on track.

If there’s anywhere you shouldn’t be cutting corners, it's finding experts you can trust.

Do you need a project manager? Here’s what they provide...

  • Preparing your tendering package
  • Interviewing / reviewing potential contractors
  • Preparing your construction contract
  • Devising a payment plan based around milestones
  • Site supervision
  • Work assessment
  • And general relationship management

Learn more: what is a project manager?

5. Get to know your materials

On the other hand, there are plenty of places you can save money when it comes to building materials. For example, if your architect suggests a slate roof, the price difference between artificial slate (at 20p per slab) vs. Welsh slate (at £1.50 per slab) can end up in the thousands.

Sometimes this will matter, and sometimes you honestly won’t be able to tell the difference. You don’t always need to go for the best; you just need to find what works for you.

6. Move out

It’s likely that a contractor will charge less for the work if you can vacate the property during your home extension, but make sure to cost out how much this is really going to save you. If you have to pay to live somewhere else, or travel further to work, it may not make sense in the end.

Pricing everything out as accurately as possible before you make any decisions is the easiest way to stay on top of your spending.

7. Be smart with your finances

Ultimately, one of the best ways to make savings while completing a home extension is through being smart with your funding. How you choose to finance the build of your extension can make a big difference to your budget, both in the long run and in the short term.

Many people choose to use savings to make ends meet, however, this isn’t always the best financing route. Being reliant on a savings account means you run the risk of running out of money at crucial times, you're less prepared for price increases (such as those seen in 2020 and 2021), and you’re not taking advantage of any equity you’ve already gained from your home.

Talking to a financial advisor is a great way to make sure you get the most out of your money during this process. You might find that you’re able to utilise the value your extension creates to lower the cost of your future loan repayments, or you might discover some fantastic remortgaging deals. Either way, it’s worth booking an appointment with an expert.

Luckily, our Resi Finance team is always on hand to help. Visit our loan tool to explore the deals currently on the market, or book yourself in for a FREE consultation to discuss budgets, planning, and everything else extension related with our team.

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