Last updated on April 4th, 2023
New home foundation cost guide
The foundations to your house, garage or conservatory provide the solid base on which the structure rests. New home foundation costs can vary according to a range of factors, including the size of the building, the soil type, the kind of foundations you are laying and accessibility to the site itself.
The average costs included are for building the new foundations, and don’t include any professional fees you may encounter.
| Foundation | Unit | Cost + VAT (low) | Cost + VAT (high) | Average Cost |
|---|---|---|---|---|
| Strip foundation Excavation Depth 1m, Width 0.6m, Concrete thickness 0.3m | Per LM | £95 | £115 | £105 |
| Strip foundation (hand dig) Excavation Depth 1m, Width 0.6m, Concrete thickness 0.3m | Per LM | £170 | £220 | £195 |
| Trench foundation Excavation Depth 1m, Width 0.6m, Concrete thickness 0.7m | Per LM | £130 | £160 | £145 |
| Trench foundation (hand dig) Excavation Depth 1m, Width 0.6m, Concrete thickness 0.7m | Per LM | £220 | £280 | £250 |
| Raft foundation | Per M2 | £200 | £260 | £230 |
| Reinforcement | Per M2 | £50 | £70 | £60 |
| Concrete pump | Per day | £300 | £400 | £350 |
| Labour | Per day | £200 | £250 | £225 |
Our costs are ballpark averages – get a local tradesperson to quote now
Hand dig costs include additional labour to manually excavate due to reduced site access. The table costs do not include block and block cavity walls up to the Damp Proof Course (DPC).
What are the factors affecting the installation of new foundations?
Before we dig into the detail, laying foundations is covered by building regulations which means you will need approval from your local authority before any work can take place. Your architect and builder will usually take care of this.
You may also need to notify your neighbours if any works are adjacent to their property, as outlined in the Party Wall Act. We’ve not included the costs of an architect or any surveyors costs you may need to cover in this guide.
The costs in the table and this guide are from the online estimators at My Build Estimate – a professional estimating company monitored by the Royal Institution of Chartered Surveyors (RICS).
Cost of foundations per metre
The cost of your new foundations is typically calculated per metre, and is affected by a variety of factors, including:
- Type of subsoil – The soil subtype could dramatically affect the cost of your new foundations and dictate which type of foundation you need.
- Type of foundation – There are four main types of building foundations: raft foundations, trench fill foundation, strip foundations and concrete slab foundations.
- Size of the building/structure – The larger the structure, the more extensive the foundations, and the more it will cost to install them.
- Accessibility of the site – Laying foundations involves a large amount of manpower, machinery and building supplies.
The standard depth of a foundation is approximately 1m and a width of 0.6mm. The average cost to install new foundations are:
- Strip foundations – £95 – £115 per linear metre (LM)
- Trench fill foundations – £130 – £160 per linear metre (LM)
This is based on a width of 0.6m and includes excavation (using an excavator), cart away, and concrete costs. Hand dig costs are considerably higher.
New home foundation cost calculator
If you’re trying to calculate the cost of new home foundations, you need to take a number of factors into consideration to help you work out the cost. The main ones being the size of the home you’re planning to build, the type of subsoil you’re dealing with and the type of foundation you’re planning to lay. With all of that information you should be able to get a pretty accurate quote from local construction experts.
Building foundation hourly rates
To price up the cost of building foundations, you’ll most likely be quoted per square metre – rather than an hourly rate for the project. But as a guide, you can expect to pay between £200 – £250 a day for labour to build foundations.
Why is subsoil important?
The soil your property is built on will dictate the type of foundations that are suitable to use. For the purposes of building, the Government classifies subsoil into seven types:
- Rock
- Chalk
- Gravel and sand
- Clay
- Firm clay over soft clay
- Peat
- Filled ground
Your chosen tradesperson and building inspector will be aware of the type of soil your property is built upon and can provide advice before work begins.
What are the different types of building foundations?
There are four types of building foundations that may be used to underpin your home, including trench fill foundations, strip foundations, concrete slab foundations and raft foundations.
Trench fill foundations
Trench filled foundations are trenches that are filled just below ground level with concrete to provide a solid base for the structure. Trench fill foundations are simple to build and less labour intensive than other methods, which compensates for the higher cost of materials.
For trench fill foundations you should expect to pay between £130 – £160 per metre using an excavator and £220 – £280 per metre for hand dig.
Strip foundations
When laying strip foundations, your builder will excavate a trench and lay a solid base of concrete. They will build up from this base in blockwork until they reach ground, when your builder can switch to laying bricks, stones or your choice of material.
Strip foundations will cost between £95 – £115 per metre using an excavator and £170 – £220 per metre for hand dig.
Concrete slab foundations
Concrete slab foundations are foundations made from concrete which is either poured over the ground or laid in individual blocks. Slab foundations are cheap to lay and are very strong and hard.
The cost per square metre of concrete slab foundations will need a building design, as there are significant variables.
Raft foundations
Raft foundations involve a solid concrete base (or raft) made up of reinforced concrete being poured on top of the soil covering the entire area of the building. It’s used when other methods, such as strip foundations, aren’t suitable – where soil pressure is low, for example.
You should expect to pay between £200 – £260 per M2 for raft foundations.
What type of foundations do I need?
As part of your planning application, your architect, tradesperson, and structural engineer will be responsible for ensuring that the selected type and size of foundations meet the current guidelines for new buildings.
The building inspector will ensure that the foundations you are laying are correct for the type of building and the subsoil before you are allowed to build.
During the laying of foundations, your building inspector may visit the site to check their condition.
New home foundation quote
We recommend obtaining at least three quotes from our trusted tradespeople. Our post a job feature is perfect for getting quotes – you post details about the job you want doing and we’ll send it out to local tradespeople in your area. Try it out.
Key takeaways when analysing new foundation costs
- The average cost to lay strip foundations is £105 per linear metre (using an excavator).
- The average cost to lay trench foundations is £145 per linear metre (using an excavator).
- Total cost of foundations per metre depends on the size of the building, the condition of the soil, the type of foundation selected and the ease of access to the site.
- All work must receive approval from your local authority
- If you’re building close to neighbouring properties, you must gain party wall approval.
- New foundation costs may vary across the UK.
The tick you can trust
8/10 homeowners would choose a tradesperson endorsed by Checkatrade over one who isn't*
Claims are sourced from a survey conducted by Deep Blue Thinking on a nationally representative UK sample in November 2021. *8 out of 10 people would choose a trade endorsed by Checkatrade compared to one that isn’t endorsed.
Claims are sourced from a survey conducted by Deep Blue Thinking on a nationally representative UK sample in November 2021. *8 out of 10 people would choose a trade endorsed by Checkatrade compared to one that isn’t endorsed.
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