How to Estimate Your Build Costs

Build It Live is the perfect place to come to find the answers to your questions, speak to industry experts and gain the knowledge and inspiration you need to make your project a success. Before you come along, gain some top tips below – put together by the experts at Build It magazine.

Establishing build costs

If you’re planning a self build project, there’s probably a big question at the front of your mind: how much will it cost? You’re understandably going to want to achieve the best design and build quality you can afford, without paying over the odds.

The key to achieving this is to draw up an accurate budget and cost plan. The first step is to look closely at your savings and any equity you have in existing property. You should also investigate what kind of funds you could bring in via a self build mortgage. You’ll then have an idea of what you can afford in terms of plot and construction.

Your overall cost plan should include things like professional fees and a 10% contingency fund. If you already have a plot in mind, you can subtract the cost of the land, which is usually about 30 to 40% of the overall spend, from your total sum. This will give you an idea of how much you’ll have left for the actual work.

Remember to budget for things like land valuation, stamp duty, solicitor’s fees and security compliance.

What can I build with my budget?

Once you’ve established a rough construction budget, you need to know whether it’s enough to actually build with. The traditional method for achieving this is to use a standard per m2 rate and multiply that by the house size you want.

However, using this method is an inexact science and there are so many variables, especially given the current uncertainty of the market. In reality, a whole host of factors will affect your budget, and you could easily end up spending significantly more or less.

With the per m2 rate, there’s always a margin for error and you’re unlikely to get a final picture of costs until you can start to identify your materials and labour requirements.

However, the Build Cost Calculator is one way of getting an accurate idea of how much your project will cost. Estimate your project costs instantly with this interactive self build too. Find out how much it will cost to build your house, including total building costs and a price per m2.

You can also use Build It’s Estimating Service. This tool is powered by award-winning HBXL software and has been used by hundreds of self builders on projects ranging from garage conversions to full family homes.

All you need to do is submit your proposed floor and elevation plans, along with any relevant specification notes. In return, you’ll receive:

  • A fully detailed, self builder-friendly estimate report
  • Live material costs from leading builder’s merchants
  • Estimated labour costs
  • A full cost breakdown to assist with finance applications
  • The option to make adjustments to suit your budget
  • Support to better understand your build route options

This tailored, personal service starts from just £249. Since the report is so detailed, you’ll easily be able to identify where you could make changes to the spec.

How your plot could affect costs

Every self build starts with a plot and the nature of it can have a big impact on your outlay for the construction work. This is due to a number of reasons, including ground condition issues. Poor soils, high water tables or sloping sites can all mean greater expense. Another factor is how difficult it is to get utilities installed on site. We recommend getting estimates from all service providers to see if the quotes look reasonable.

Finally, if there are specimens close to your planned building, the foundations may need strengthening. The design might need to account for examples subject to tree preservation orders (TPOs), too. If a protected specimen is in the wrong place, it could render the site undevelopable.

Always check the above before you purchase a plot. In fact, it’s always worth bringing in a planning consultant to assist with the site appraisal. While it will cost you to hire another pair of hands, their advice will probably help you to avoid expensive surprises later on. Your architect or structural engineer should also be able to provide guidance.

How Build It Live Can Help

So, how can you benefit from a visit to Build It Live? Well, at the show, we’ll have experts on hand all weekend, providing advice on everything from financing to design – and much more.

Ask Our Experts

Don’t miss the chance to book a one-to-one appointment with one of our experts, at the Ask Out Experts lounge. Bring your plans, if you have some, and don’t forget your list of questions. They’ll be able to provide you with personalised advice and give you all the information you need – on budgeting and more.

Build Cost Clinic

Head to the Build Cost Clinic to book an appointment with one of our qualified estimators. Tell them your plans and they’ll be able to provide advice to help you better understand how much it will cost to build the home of your dreams. They can offer guidance on where you could save money and can also talk you through Build It’s Estimating Service, if you’re keen to learn more.

Seminars & Workshops

We’ll also have dedicated seminars on each day, covering a variety of essential self build and renovation topics, including A step by step guide to self build, which covers everything from finding land to setting a budget.

A range of industry experts and suppliers will also be taking to the Workshop Theatre stage, to host a range of talks. These workshops cover all kinds of important topics and vary at each show, so keep an eye on the schedule.


At every Build It Live show you’ll be able to meet hundreds of suppliers and companies, browse thousands of products and gain the advice and inspiration you need. Explore our full list of Exhibitors here and make a list of all the companies you’d like to meet during your trip.

Explore our full show line-up today and start planning your visit.