Wales regional pricing

How Much Does a Builder Cost in Swansea?

Updated prices for . Swansea prices are typically 5% below the national average.

14 services priced
Wales region
Updated

Price summary

Swansea Price Summary

Service Low Average High
Single Storey Extension £28,590 £47,650 £76,240
Double Storey Extension £47,650 £81,005 £133,420
Loft Conversion £23,825 £42,885 £71,475

Prices include labour and materials. VAT may apply. Based on Wales regional pricing.

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Full pricing

All Builder Prices in Swansea

Every price adjusted for Swansea using a 0.953x cost multiplier, rounded to the nearest £5.

Single Storey Extension

Low

£28,590

Average

£47,650

High

£76,240

8-12 weeks

Double Storey Extension

Low

£47,650

Average

£81,005

High

£133,420

12-20 weeks

Loft Conversion

Low

£23,825

Average

£42,885

High

£71,475

6-10 weeks

Garage Conversion

Low

£7,625

Average

£14,295

High

£23,825

2-4 weeks

Porch Build

Low

£2,385

Average

£4,290

High

£7,625

1-2 weeks

Garden Wall

Low

£760

Average

£1,430

High

£2,860

2-4 days

Knock Through Internal Wall

Low

£955

Average

£1,715

High

£3,335

2-4 days

Chimney Breast Removal

Low

£1,145

Average

£1,905

High

£3,335

2-4 days

Underpinning

Low

£4,765

Average

£11,435

High

£23,825

2-4 weeks

Damp Proof Course

Low

£475

Average

£1,145

High

£2,385

1-3 days

New Build Garage

Low

£9,530

Average

£17,155

High

£28,590

3-5 weeks

Outbuilding or Garden Room

Low

£11,435

Average

£23,825

High

£47,650

3-6 weeks

Structural Steelwork (RSJ Installation)

Low

£955

Average

£1,715

High

£2,860

1-2 days

Patio or Decking Build

Low

£1,430

Average

£3,335

High

£6,670

3-5 days

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Regional comparison

How Swansea Compares

Average cost of single storey extension across regions.

Swansea
-5% £47,650
National Average
baseline £50,000
London
+24% £62,150

Local insights

What Affects Builder Costs in Swansea?

Wales has a distinctive mix of housing, from Victorian and Edwardian terraces in the south to stone-built cottages and rural properties across the rest of the country. Swansea and the wider area around Swansea and the Valleys include many older properties that present challenges for builder work. Stone walls, exposed locations, and older infrastructure all tend to push costs toward the higher end.

Wales sits below the national average for trade costs. Labour rates in Swansea are typically 5% below the UK average. While this makes builder work more affordable, there can be fewer qualified professionals in rural areas compared to English cities, which can mean longer waiting times. In more populated areas, competition keeps prices reasonable. Always get at least three quotes.

Properties in Swansea can present specific challenges that affect builder costs. Stone-built and older Welsh terraces often have thick walls that make work more difficult and expensive. Properties in exposed or rural locations may face harsher weather conditions that influence timing and approach. For larger jobs in Swansea, expect to pay £47,650 to £133,420 for double storey extension.

When getting quotes in Swansea, aim for at least 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 existing conditions, identify complications, and provide a detailed cost breakdown. Be wary of quotes that seem significantly cheaper — they may be cutting corners on materials or quality. Always check qualifications, insurance and recent reviews.

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More services

Other Services in Swansea

Explore costs for other services in the Swansea area.

40 services — scroll to explore

Common questions

Frequently Asked Questions

Common questions about builder costs in Swansea.

How much does a builder cost in Swansea in 2026?
Single Storey Extension in Swansea typically costs between £28,590 and £76,240, with the average being around £47,650. Prices vary depending on the scope of work, materials used, and the specific requirements of your property.
Are builder prices cheaper in Swansea than London?
Yes. Swansea builder costs are typically 5% below the national average, while London prices run around 24% above it. For single storey extension, you could save over £14,500 compared to the same job in London.
How do I find a good builder in Swansea?
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 Swansea?
The main factors are the scope and complexity of what you need, the options and products chosen, and local market rates. Swansea rates are 5% below the national average. Getting multiple quotes is the best way to ensure a fair price.
Do builder prices include materials in Swansea?
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.