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.

14 services priced
North West region
Updated

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.

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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.

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

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Regional comparison

How St. Helens Compares

Average cost of single storey extension across regions.

St. Helens
-2% £49,050
National Average
baseline £50,000
London
+24% £62,150

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.

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More services

Other Services in St. Helens

Explore costs for other services in the St. Helens area.

40 services — scroll to explore

Common questions

Frequently Asked Questions

Common questions about builder costs in St. Helens.

How much does a builder cost in St. Helens in 2026?
Single Storey Extension in St. Helens typically costs between £29,430 and £78,480, with the average being around £49,050. Prices vary depending on the scope of work, materials used, and the specific requirements of your property.
Are builder prices cheaper in St. Helens than London?
Yes. St. Helens builder costs are typically 2% below the national average, while London prices run around 24% above it. For single storey extension, you could save over £13,100 compared to the same job in London.
How do I find a good builder in St. Helens?
Get at least three quotes from different tradespeople, check recent reviews, and ask whether the quote includes VAT and everything you need. A detailed written quote that breaks down all costs is a good sign. Always check qualifications, insurance and recent reviews before hiring.
What affects builder prices in St. Helens?
The main factors are the scope and complexity of what you need, the options and products chosen, and local market rates. St. Helens rates are 2% below the national average. Getting multiple quotes is the best way to ensure a fair price.
Do builder prices include materials in St. Helens?
The prices shown on this page include all typical costs. However, when getting real quotes, always confirm what is and isn't included. Some tradespeople break out costs separately, while others give an all-in price. Ask for a detailed breakdown before agreeing to any work.