North West regional pricing
How Much Does a Builder Cost in St. Helens?
Updated prices for . St. Helens prices are typically 2% below the national average.
Price summary
St. Helens Price Summary
| Service | Low | Average | High |
|---|---|---|---|
| Single Storey Extension | £29,430 | £49,050 | £78,480 |
| Double Storey Extension | £49,050 | £83,385 | £137,340 |
| Loft Conversion | £24,525 | £44,145 | £73,575 |
Prices include labour and materials. VAT may apply. Based on North West regional pricing.
Full pricing
All Builder Prices in St. Helens
Every price adjusted for St. Helens using a 0.981x cost multiplier, rounded to the nearest £5.
| Job | Low | Average | High | Duration |
|---|---|---|---|---|
| Single Storey Extension | £29,430 | £49,050 | £78,480 | 8-12 weeks |
| Double Storey Extension | £49,050 | £83,385 | £137,340 | 12-20 weeks |
| Loft Conversion | £24,525 | £44,145 | £73,575 | 6-10 weeks |
| Garage Conversion | £7,850 | £14,715 | £24,525 | 2-4 weeks |
| Porch Build | £2,455 | £4,415 | £7,850 | 1-2 weeks |
| Garden Wall | £785 | £1,470 | £2,945 | 2-4 days |
| Knock Through Internal Wall | £980 | £1,765 | £3,435 | 2-4 days |
| Chimney Breast Removal | £1,175 | £1,960 | £3,435 | 2-4 days |
| Underpinning | £4,905 | £11,770 | £24,525 | 2-4 weeks |
| Damp Proof Course | £490 | £1,175 | £2,455 | 1-3 days |
| New Build Garage | £9,810 | £17,660 | £29,430 | 3-5 weeks |
| Outbuilding or Garden Room | £11,770 | £24,525 | £49,050 | 3-6 weeks |
| Structural Steelwork (RSJ Installation) | £980 | £1,765 | £2,945 | 1-2 days |
| Patio or Decking Build | £1,470 | £3,435 | £6,865 | 3-5 days |
Single Storey Extension
Low
£29,430
Average
£49,050
High
£78,480
8-12 weeks
Double Storey Extension
Low
£49,050
Average
£83,385
High
£137,340
12-20 weeks
Loft Conversion
Low
£24,525
Average
£44,145
High
£73,575
6-10 weeks
Garage Conversion
Low
£7,850
Average
£14,715
High
£24,525
2-4 weeks
Porch Build
Low
£2,455
Average
£4,415
High
£7,850
1-2 weeks
Garden Wall
Low
£785
Average
£1,470
High
£2,945
2-4 days
Knock Through Internal Wall
Low
£980
Average
£1,765
High
£3,435
2-4 days
Chimney Breast Removal
Low
£1,175
Average
£1,960
High
£3,435
2-4 days
Underpinning
Low
£4,905
Average
£11,770
High
£24,525
2-4 weeks
Damp Proof Course
Low
£490
Average
£1,175
High
£2,455
1-3 days
New Build Garage
Low
£9,810
Average
£17,660
High
£29,430
3-5 weeks
Outbuilding or Garden Room
Low
£11,770
Average
£24,525
High
£49,050
3-6 weeks
Structural Steelwork (RSJ Installation)
Low
£980
Average
£1,765
High
£2,945
1-2 days
Patio or Decking Build
Low
£1,470
Average
£3,435
High
£6,865
3-5 days
Regional comparison
How St. Helens Compares
Average cost of single storey extension across regions.
Local insights
What Affects Builder Costs in St. Helens?
St. Helens's housing stock is dominated by Victorian and Edwardian terraced houses, with large numbers of properties across the wider metropolitan area and surrounding towns. These older homes often present challenges for builder work, including limited access, older infrastructure and the need for more preparation. Properties that haven't been updated in decades tend to push costs toward the higher end of the ranges shown above.
The North West consistently sits below the national average for trade costs, and St. Helens is no exception. Labour rates here are around 2% below the UK average and considerably lower than London or the South East. This reflects both the lower cost of living and a healthy supply of qualified builder professionals across the region. That said, prices can still vary by 30-50% between different tradespeople for the same job, making multiple quotes essential.
Several factors affect builder costs in St. Helens. Back-to-back terraces may have limited access that makes work more complicated and expensive. Properties with solid walls rather than cavities can add to the difficulty. For larger projects, expect costs at the higher end — a double storey extension in St. Helens typically runs £49,050 to £137,340. Material and product choices also make a significant difference to the total.
When getting quotes in St. Helens, aim for a minimum of three from different qualified professionals. Ask each one to visit and assess the work rather than quoting over the phone. A good builder will check the existing conditions, identify potential complications, and provide a clear cost breakdown. Be wary of quotes that seem significantly cheaper than others — they may be cutting corners on materials or quality. Always check qualifications, insurance and recent reviews before hiring.
More services
Other Services in St. Helens
Explore costs for other services in the St. Helens area.
40 services — scroll to explore
UK-wide pricing
Builder Costs in Other Cities
Compare builder prices across the UK.
Common questions
Frequently Asked Questions
Common questions about builder costs in St. Helens.