House foundations cost between £8,000 and £35,000 for most UK homes, depending on your foundation type, soil conditions, and property size. Strip foundations typically cost £80-120 per linear metre, whilst concrete slab foundations range from £40-80 per square metre.
If you’re planning a new build, extension, or dealing with foundation problems, understanding these costs helps you budget properly and avoid nasty surprises.
What Determines Foundation Costs?
Foundation Type Makes the Biggest Difference
Your foundation type drives most of your costs. Here’s what you’ll pay:
Strip Foundations (Most Common)
- Shallow strip: £80-120 per linear metre
- Deep strip: £150-250 per linear metre
- Wide strip: £200-350 per linear metre
Concrete Slab Foundations
- Standard slab: £40-80 per square metre
- Reinforced slab: £60-100 per square metre
- Insulated slab: £80-120 per square metre
Pile Foundations (Problem Ground)
- Mini piles: £150-300 per pile
- Bored piles: £200-400 per pile
- Steel piles: £100-250 per pile
Ground Conditions Add Complications
Your soil type dramatically affects costs. Clay soils expand and contract, requiring deeper foundations. Rocky ground needs expensive excavation equipment.
Easy Ground Conditions:
- Sandy soil: Standard pricing
- Stable clay: 10-20% premium
- Level sites: No extra costs
Difficult Ground Conditions:
- Expansive clay: 30-50% price increase
- Rocky ground: 25-40% extra for excavation
- Sloping sites: 20-30% additional costs
- High water table: 15-25% premium for drainage
Size and Complexity Matter
A typical three-bedroom house needs roughly 40-60 linear metres of strip foundation. Complex shapes, multiple levels, or large spans increase both materials and labour costs.
Detailed Foundation Cost Breakdown
Strip Foundation Costs
Strip foundations support load-bearing walls. They’re the most common choice for UK homes.
| Foundation Depth | Cost Per Linear Metre | Typical Use |
|---|---|---|
| 450mm shallow | £80-120 | Good ground conditions |
| 900mm standard | £120-180 | Normal clay soils |
| 1500mm deep | £180-250 | Expansive clay |
| 2500mm+ very deep | £250-400+ | Problem soils |
What’s Included:
- Excavation and disposal
- Concrete and reinforcement
- Damp-proof course
- Backfilling and compaction
Additional Costs:
- Building control fees: £300-800
- Structural engineer: £500-1,500
- Ground investigation: £800-2,000
Concrete Slab Foundation Costs
Slab foundations work well for extensions, garages, and some new builds.
| Slab Type | Cost Per m² | Best For |
|---|---|---|
| Basic concrete slab | £40-60 | Garages, workshops |
| Reinforced slab | £60-90 | Residential extensions |
| Insulated slab | £80-120 | Energy-efficient homes |
| Beam and block | £90-140 | Suspended floors |
Pile Foundation Costs
When ground conditions are poor, piles transfer loads to stable ground deeper down.
Mini Pile Systems:
- 4-6 metre piles: £150-200 each
- 6-10 metre piles: £200-300 each
- Ground beam connections: £80-120 per metre
When You Need Piles:
- Very soft or unstable ground
- High water table issues
- Previous ground contamination
- Significant level changes
Labour and Material Costs
Labour Costs Breakdown
Foundation work requires skilled contractors. Labour typically represents 40-60% of total costs.
Daily Rates:
- Groundworker: £200-300 per day
- Machine operator: £250-350 per day
- Concrete specialists: £250-400 per day
Project Duration:
- Simple strip foundation: 3-5 days
- Complex foundation: 1-2 weeks
- Pile foundations: 1-3 weeks depending on quantity
Material Costs
Concrete Prices:
- Ready-mix concrete: £90-120 per cubic metre
- High-strength concrete: £110-140 per cubic metre
- Delivery surcharge: £50-80 per load
Other Materials:
- Reinforcement steel: £1.20-1.80 per kg
- Damp-proof course: £3-6 per linear metre
- Hardcore/sub-base: £25-35 per tonne
- Formwork: £15-25 per square metre
Regional Cost Variations
Foundation costs vary significantly across the UK due to labour rates, material availability, and ground conditions.
London and South East:
- Premium: 20-40% above national average
- Strip foundations: £100-160 per linear metre
- High demand drives prices up
Northern England and Scotland:
- Discount: 10-20% below national average
- Strip foundations: £70-100 per linear metre
- More competitive contractor rates
Wales and Southwest:
- Average pricing: Similar to national rates
- Transport costs can add £500-1,000 to materials
Hidden Costs and Unexpected Expenses
Ground Investigation Surprises
Poor ground conditions discovered during excavation can double your foundation costs. A proper ground investigation report costs £800-2,000 but prevents expensive surprises.
Common Ground Issues:
- Underground services requiring diversion: £2,000-8,000
- Contaminated soil removal: £5,000-15,000
- Unexpectedly high water table: £1,000-5,000
- Rock requiring breaking: £2,000-10,000
Planning and Regulatory Costs
Building Control:
- Application fee: £300-500
- Inspection fees: £200-300
- Structural calculations: £500-1,500
Planning Permission (if required):
- Householder application: £206
- Full planning application: £462
- Possible architect fees: £1,000-5,000
Weather and Access Issues
Bad weather can delay projects and increase costs. Poor site access requires smaller machinery or hand digging.
Weather Delays:
- Extended hire costs: £100-200 per day
- Additional pumping: £200-500
- Concrete protection: £300-800
How to Reduce Foundation Costs
Get Multiple Quotes
Always obtain three detailed quotes from qualified groundwork contractors. Prices can vary by 30-50% for identical work.
Quote Checklist:
- Detailed breakdown of labour and materials
- Clear scope of work included
- Contingency allowances for ground conditions
- Insurance and warranty information
Choose the Right Foundation Type
Don’t over-engineer your foundations. A structural engineer can recommend the most cost-effective solution for your specific conditions.
Cost-Saving Options:
- Trench fill instead of traditional strip
- Standard depth where ground allows
- Simple rectangular shapes
- Good site access planning
Time Your Project Well
Best Times for Foundation Work:
- Late spring through early autumn
- Avoid December-February if possible
- Book contractors early for competitive rates
Prepare Your Site Properly
Clear access saves money on smaller machinery. Remove obstacles and provide adequate working space.
Site Preparation Savings:
- Clear access for large concrete trucks
- Provide secure storage for materials
- Ensure utility locations are marked
- Have building control arranged in advance
Working with Contractors
Finding Qualified Foundation Contractors
Look for contractors with proper credentials and relevant experience.
Essential Qualifications:
- Public liability insurance (minimum £2 million)
- Construction Industry Scheme (CIS) registration
- Relevant trade certifications
- Previous project references
Red Flags:
- Door-to-door sales approaches
- Demands for large upfront payments
- No fixed business address
- Lack of insurance documentation
Understanding Your Quote
A proper foundation quote should break down all costs clearly.
Quote Should Include:
- Excavation and disposal costs
- Concrete quantity and grade
- Steel reinforcement specifications
- Labour costs and duration
- Material delivery charges
- VAT and any additional fees
Payment Schedule:
- 10% deposit maximum
- Progress payments tied to work completed
- Final payment on completion
- Never pay large amounts upfront
Common Foundation Problems and Costs
Settlement Issues
Foundation settlement can crack walls and cause structural damage. Underpinning costs £1,000-3,000 per linear metre.
Warning Signs:
- Cracks in walls or ceilings
- Doors and windows sticking
- Uneven floors
- Gaps around frames
Damp Problems
Poor foundation drainage causes damp issues. Remedial work costs £2,000-8,000 depending on severity.
Prevention Measures:
- Proper damp-proof course installation
- Adequate site drainage
- Correct concrete specification
- Professional installation oversight
Foundation Costs for Different Property Types
New Build Houses
Small House (2-bed):
- Strip foundations: £4,000-8,000
- Slab foundation: £3,000-6,000
- Total including labour: £6,000-12,000
Medium House (3-4 bed):
- Strip foundations: £8,000-15,000
- Slab foundation: £6,000-12,000
- Total including labour: £12,000-22,000
Large House (4+ bed):
- Strip foundations: £15,000-25,000
- Slab foundation: £12,000-20,000
- Total including labour: £20,000-35,000
Extensions
Single-storey extension:
- 20m² extension: £2,000-4,000
- 40m² extension: £4,000-8,000
- Including connections: Add 20-30%
Two-storey extension:
- Deeper foundations required
- 25-40% premium over single storey
- Structural calculations essential
Garage Foundations
Single garage:
- Concrete slab: £800-1,500
- Strip foundations: £1,200-2,500
- Block and beam: £1,500-2,800
When to Call Professionals
Structural Engineer Consultation
Always use a structural engineer for:
- Houses over two storeys
- Extensions to existing buildings
- Unusual ground conditions
- Load-bearing wall changes
Engineer Costs:
- Initial consultation: £300-600
- Full structural design: £800-2,000
- Site inspections: £200-400 per visit
Building Control Involvement
Building control approval is mandatory for most foundation work. They inspect at key stages to ensure compliance with Building Regulations.
Inspection Stages:
- Excavation and before concrete
- Foundation completion
- Damp-proof course level
- Final completion
Making the Right Foundation Choice
Your foundation choice affects your home for decades. Consider long-term performance, not just initial cost.
Key Decision Factors:
- Ground conditions and soil report
- Building design and loads
- Local building regulations
- Budget and timeline constraints
- Future extension possibilities
Professional Advice Sources:
- Institution of Structural Engineers for qualified engineers
- Federation of Master Builders for contractors
- Local building control for regulatory guidance
Conclusion
House foundation costs range from £8,000-35,000 for most UK properties, with strip foundations at £80-250 per linear metre being the most common choice. Your final cost depends on foundation type, ground conditions, property size, and local labour rates.
The key to controlling costs is proper planning. Get a ground investigation, obtain multiple quotes from qualified contractors, and choose the right foundation type for your specific conditions. Don’t cut corners on structural design – it’s cheaper to build it right the first time than fix problems later.
Remember that foundations are a long-term investment. Quality work costs more upfront but saves money and stress over your property’s lifetime. Always use qualified professionals and ensure proper building control approval for safe, compliant foundations.
Frequently Asked Questions
How much do house foundations cost per square metre?
Foundation costs vary by type: concrete slabs cost £40-120 per m², whilst strip foundations cost £80-250 per linear metre. Total costs depend on your specific ground conditions and foundation requirements.
What’s the cheapest type of house foundation?
Concrete slab foundations are typically the cheapest option at £40-80 per m² for basic installations. However, the most cost-effective choice depends on your ground conditions and building requirements.
Do I need a structural engineer for foundation work?
Yes, you need a structural engineer for most foundation projects. They ensure your foundations meet building regulations and are suitable for your ground conditions. Costs range from £500-2,000.
How long do house foundations take to install?
Simple strip foundations take 3-5 days, whilst complex foundations with challenging ground conditions can take 1-3 weeks. Weather conditions and site access also affect timeline.
Can I reduce foundation costs by doing some work myself? Foundation work requires qualified contractors due to building regulations and structural requirements. You can reduce costs by preparing site access, obtaining multiple quotes, and choosing appropriate foundation types for your conditions.