South West regional pricing

How Much Does a Builder Cost in South Gloucestershire?

Updated prices for . South Gloucestershire prices are typically 5% above the national average.

14 services priced
South West region
Updated

Price summary

South Gloucestershire Price Summary

Service Low Average High
Single Storey Extension £31,650 £52,750 £84,400
Double Storey Extension £52,750 £89,675 £147,700
Loft Conversion £26,375 £52,750 £84,400

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

Full pricing

All Builder Prices in South Gloucestershire

South Gloucestershire is in South West England and builder costs here are 5% above the national average. Prices are based on real regional wage data from the Office for National Statistics.

All prices include materials and labour unless stated otherwise. Prices verified 2026

Single Storey Extension

Low

£31,650

Average

£52,750

High

£84,400

8-12 weeks

More details

Building a single storey rear or side extension, typically 15-25m². Includes foundations, walls, roof, windows, plastering and basic electrics and plumbing. Does not include kitchen or bathroom fitting.

~45% labour, ~55% materials

What affects the price

  • Size of extension in square metres
  • Foundation complexity and ground conditions
  • Roof type (flat or pitched)
  • Whether planning permission is required
  • Level of internal finish and specification

Double Storey Extension

Low

£52,750

Average

£89,675

High

£147,700

12-20 weeks

More details

Building a two storey extension to the rear or side of a property. Includes foundations, structural walls, first floor, roof, windows, stairs if needed, plastering and basic services. Typically 30-50m² total floor area.

~47% labour, ~53% materials

What affects the price

  • Total floor area across both storeys
  • Structural engineer requirements
  • Integration with existing roof and walls
  • Whether planning permission is required
  • Internal specification and fit-out level

Loft Conversion

Low

£26,375

Average

£52,750

High

£84,400

6-10 weeks

More details

Turning your loft into a proper room you can live in, with roof windows or a dormer (a box-shaped extension built out from the roof to add headroom). Includes strengthening the floor, insulation, a new staircase, plastering, electrics, and flooring. Price is for a typical dormer conversion.

~53% labour, ~47% materials

What affects the price

  • Type of conversion (Velux, dormer, mansard, hip-to-gable)
  • Existing roof structure and head height
  • Whether a bathroom or en-suite is included
  • Staircase design and location
  • Planning permission and party wall requirements

Garage Conversion

Low

£8,440

Average

£15,825

High

£26,375

2-4 weeks

More details

Turning your garage into a room you can use as a living space, office, or bedroom. The garage door opening is bricked up (with a window), and the walls and floor are insulated, damp-proofed, plastered, and finished with proper flooring and electrics.

~47% labour, ~53% materials

What affects the price

  • Whether the garage is integral, attached or detached
  • Condition of the existing structure
  • Damp proofing and insulation requirements
  • Level of finish (basic vs high spec)
  • Whether plumbing is needed for a utility or bathroom

Porch Build

Low

£2,640

Average

£4,750

High

£8,440

1-2 weeks

More details

Building a new front porch with foundations, walls, roof and door. Typical size around 2-3m². Includes brickwork or rendered blockwork to match the existing house, tiled or flat roof, lighting and a new front door.

~42% labour, ~58% materials

What affects the price

  • Size and design of the porch
  • Materials (brick, uPVC, timber, rendered block)
  • Roof type (tiled, flat, lead)
  • Whether planning permission is needed (over 3m² usually requires it)
  • Matching existing house materials and style

Garden Wall

Low

£845

Average

£1,585

High

£3,165

2-4 days

More details

Building a new brick or block garden boundary wall, typically 5-10 metres long and 1-1.5 metres high. Includes excavating and pouring concrete footings, brickwork, mortar joints, coping stones and pointing.

~37% labour, ~63% materials

What affects the price

  • Length and height of the wall
  • Type of brick or stone used
  • Single or double skin construction
  • Ground conditions for foundations
  • Piers, coping stones and decorative features

Knock Through Internal Wall

Low

£1,055

Average

£1,900

High

£3,695

2-4 days

More details

Removing an internal wall to create an open-plan living space. If the wall is holding up the floor or roof above (load-bearing), a steel beam will be fitted to take over that job. Includes plastering, tidying up the ceiling and floor where the wall was, and disposing of rubble. Building control approval is included.

~58% labour, ~42% materials

What affects the price

  • Whether the wall is load-bearing or non-load-bearing
  • Length and height of the opening
  • Size and weight of steel beam required
  • Structural engineer fees
  • Making good plastering, coving and flooring

Chimney Breast Removal

Low

£1,265

Average

£2,110

High

£3,695

2-4 days

More details

Removing a chimney breast on one floor to free up room space. Includes structural support for the remaining chimney above, making good walls, ceiling and floor, and disposing of rubble. Requires building control approval.

~75% labour, ~25% materials

What affects the price

  • Which floor the chimney breast is being removed from
  • Whether the chimney stack above needs supporting or removing
  • Structural engineer fees and building control
  • Making good plastering and flooring
  • Asbestos survey if property is pre-2000

Underpinning

Low

£5,275

Average

£12,660

High

£26,375

2-4 weeks

More details

Strengthening your home's foundations by digging down and adding concrete beneath them. Usually needed when the ground has shifted (subsidence), tree roots have caused movement, or you are adding an extra storey. Price is for underpinning one wall of a typical semi-detached house.

~40% labour, ~60% materials

What affects the price

  • Method used (mass concrete, beam and base, mini-piling)
  • Length of wall to be underpinned
  • Depth of new foundations required
  • Ground conditions and water table level
  • Structural engineer and building control fees

Damp Proof Course

Low

£530

Average

£1,265

High

£2,640

1-3 days

More details

Stopping damp from rising up through your walls from the ground. The builder drills holes along the bottom of the wall and injects a waterproofing cream that creates a barrier. The damp plaster inside is then stripped off and replaced with special plaster that helps the wall dry out.

~69% labour, ~31% materials

What affects the price

  • Length of wall to be treated
  • Wall thickness (single or double skin)
  • Extent of internal re-plastering needed
  • Access to external walls
  • Whether tanking or membrane is needed instead

New Build Garage

Low

£10,550

Average

£18,990

High

£31,650

3-5 weeks

More details

Building a new single detached garage from scratch with concrete base, block or brick walls, up-and-over door, pitched or flat roof and electrics. Typical size around 18m². Does not include driveway works.

~44% labour, ~56% materials

What affects the price

  • Size (single, double or triple)
  • Materials (brick, block, timber frame, prefab)
  • Roof type and covering
  • Whether planning permission is required
  • Electrical supply and lighting

Outbuilding or Garden Room

Low

£12,660

Average

£26,375

High

£52,750

3-6 weeks

More details

Building an insulated garden room or outbuilding suitable for year-round use as a home office, gym or studio. Typically 10-20m² with insulated walls, double glazed windows, electrics, heating and internal finish.

~38% labour, ~62% materials

What affects the price

  • Size and design complexity
  • Insulation level and materials (SIPs, timber frame)
  • Foundations required (concrete slab, screw piles)
  • Electrical supply, heating and plumbing
  • Internal finish level and specification

Structural Steelwork (RSJ Installation)

Low

£1,055

Average

£1,900

High

£3,165

1-2 days

More details

Supplying and fitting a steel beam to support the structure above when a wall is removed or a new opening is created. Includes a structural engineer designing the right beam size, delivery, installation, and building control inspection. The beam is usually hidden inside the ceiling afterwards.

~64% labour, ~36% materials

What affects the price

  • Length and size of the beam
  • Weight and access for delivery and lifting
  • Structural engineer fees
  • Padstone and bearing requirements
  • Fire protection and building control sign-off

Patio or Decking Build

Low

£1,585

Average

£3,695

High

£7,385

3-5 days

More details

Building a new patio or decking area, typically 15-20m². Patio includes ground preparation, sub-base, and laying slabs or porcelain tiles. Decking includes frame construction, boards, steps and balustrade if needed.

~41% labour, ~59% materials

What affects the price

  • Size of the area in square metres
  • Material choice (concrete slabs, porcelain, natural stone, softwood, composite)
  • Ground preparation and levelling required
  • Steps, edging and balustrade requirements
  • Drainage and lighting

Step by step

What's Involved in Hiring a Builder

Hiring a builder for an extension or renovation is a significant project that follows a structured process from initial design through to final sign-off.

1

Initial consultation and site visit

The builder visits your property to discuss what you want, assess the site, and identify potential issues like drainage, access, or party wall considerations. A good builder will ask questions about your budget and priorities rather than just measuring up.

2

Design, planning, and approvals

Depending on the project, you may need architectural drawings, a structural engineer's calculations, planning permission, and building regulations approval. Your builder can often recommend architects and engineers they work with, or manage the application process on your behalf.

3

Detailed quote and contract

The builder provides a fixed-price quote with a clear breakdown of labour, materials, and timescales. For larger projects, this should be backed by a written contract covering payment stages, what is included, and how variations are handled. Never agree to a large job on a handshake.

4

Groundworks and structural build

Work begins with foundations, drainage, and structural walls. This is the most disruptive phase, especially for extensions where the existing property needs opening up. Building control will inspect at key stages such as foundations, damp proof course, and structural steelwork.

5

First and second fix

First fix covers hidden work — plumbing pipes, electrical cables, insulation, and plastering. Second fix is the finishing phase — sockets, switches, skirting boards, doors, and final decoration. Other trades like electricians and plumbers work alongside the builder during these stages.

6

Snagging and sign-off

Once the build is complete, you walk through with the builder to create a snagging list of any minor defects or unfinished items. These are rectified before final payment. Building control issues a completion certificate confirming the work meets regulations — keep this safe as you will need it when selling the property.

Regional comparison

How South Gloucestershire Compares

Average cost of single storey extension across regions.

South Gloucestershire
+5% £52,750
National Average
baseline £50,000
London
+24% £62,150

Local insights

What Affects Builder Costs in South Gloucestershire?

The South West has a varied housing stock, from Georgian and Regency townhouses in cities like Bath to stone-built farmhouses, coastal cottages and modern estates across Somerset and Devon. South Gloucestershire has a range of property types and ages that can affect the scope and cost of work, and many properties in the region feature older stonework, lime render and period details that require specialist attention. With a population of null, South Gloucestershire is a area where builder costs are above average. Older and rural properties tend to push prices higher due to access difficulties and the need for sympathetic materials — double storey extension here averages around £89,675.

The South West generally sits close to or slightly below the national average for trade costs, though popular areas like Bath and Exeter can be pricier. Labour rates in South Gloucestershire are around 5% above the UK average. In South Gloucestershire, local demand for builder services varies depending on the mix of residential and commercial properties in the area. Longer travel distances between jobs in rural parts of Cornwall and Dorset mean some tradespeople factor travel time into their quotes. With fewer tradespeople based locally, you may find slightly less choice, and it is worth booking ahead for larger jobs. Prices can still vary 30-50% between different tradespeople, so always compare.

What you pay for builder work in South Gloucestershire depends on the job scope, property type and materials. Period properties with lime plaster, stone walls or listed building restrictions often need specialist approaches that cost more. Coastal properties in Dorset and Cornwall can face salt exposure and damp issues that add complexity. A typical single storey extension in South Gloucestershire costs around £52,750, while double storey extension ranges from £52,750 to £147,700. As a area that is above average, South Gloucestershire offers fair value for builder work compared to London and the South East.

When getting quotes in South Gloucestershire, aim for at least three from different qualified professionals. In more rural parts of the South West, fewer tradespeople may be available locally, so book ahead for larger jobs. Ask each one to visit and assess the work rather than quoting over the phone. A good builder will check the existing conditions, flag any complications from older or period features, and give you a detailed cost breakdown. With fewer tradespeople based locally, you may find slightly less choice, and it is worth booking ahead for larger jobs. Be wary of quotes that seem significantly cheaper — they may be cutting corners on materials or quality. Always check qualifications, insurance and recent reviews before hiring.

Depending on the work involved, you may also need roofing (£85–£290), plastering (£420–£1,055), or electrician (£4,220–£8,440) in South Gloucestershire.

Common questions

Frequently Asked Questions

Common questions about builder costs in South Gloucestershire.

Do I need planning permission for an extension?
Many single-storey rear extensions fall under permitted development and do not need planning permission, provided they meet size and height limits. However, you will still need building regulations approval for structural, electrical and drainage work. Always check with your local planning authority before starting.
What is the difference between planning permission and building regulations?
Planning permission controls what you can build and where, including size, appearance and impact on neighbours. Building regulations ensure the work itself meets safety and structural standards. You may need one, both, or neither depending on the project.
Should I use a fixed price or day rate for building work?
A fixed price gives you cost certainty and puts the risk on the builder. A day rate can work out cheaper for small or unpredictable jobs, but costs can spiral if the work takes longer than expected. For anything over a few days, a fixed price with a clear scope of work is usually the safer choice.
What does a party wall agreement involve?
If your building work affects a shared wall or boundary with a neighbour, you need to serve a Party Wall Notice under the Party Wall Act 1996. If your neighbour agrees in writing, no further action is needed. If they dissent, both parties must appoint a surveyor to draw up an agreement, which typically costs around 1,000 per neighbour.
How do I find a reliable builder in the UK?
Personal recommendations from friends and family are the most reliable route. Failing that, look for builders who are members of the Federation of Master Builders (FMB) or the National Federation of Builders (NFB), as these bodies vet members and offer dispute resolution. Always get at least three quotes and ask to see examples of similar completed work.
What payment schedule is normal for building work?
A typical payment schedule is a small deposit (10-15%) to secure the start date, then staged payments at agreed milestones such as foundations complete, roof on, first fix done, and final completion. Never pay the full amount upfront. Retaining 5-10% until snagging is resolved is standard practice.
Do I need an architect for a house extension?
Not always. Simple rear extensions can often be designed by a builder or an architectural technician. However, for larger or more complex projects — especially those needing planning permission — a RIBA-registered architect will produce better designs and handle the planning application. Their fee is typically 7-12% of the build cost.
How much disruption should I expect during an extension build?
Expect significant disruption during the first few weeks when foundations are dug and walls are built. There will be noise, dust, and tradespeople coming and going. Most families stay in the property throughout, but some prefer to move out for the messiest phases. Your builder should protect existing floors and keep the site tidy at the end of each day.
What is a building control completion certificate and why does it matter?
A completion certificate confirms that the building work meets current Building Regulations. It is issued by your local authority or an approved inspector once all inspections are passed. You will need this certificate when selling your home, and your solicitor will flag any missing certificates during the conveyancing process.
How much does a builder cost in South Gloucestershire in 2026?
Single Storey Extension in South Gloucestershire typically costs between £31,650 and £84,400, with the average being around £52,750. Prices vary depending on the scope of work, materials used, and the specific requirements of your property.
Are builder prices cheaper in South Gloucestershire than London?
South Gloucestershire prices are 5% above the national average, though still £9,400 cheaper than London for single storey extension.
How do I find a good builder in South Gloucestershire?
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 South Gloucestershire?
The main factors are the scope and complexity of what you need, the options and products chosen, and local market rates. South Gloucestershire rates are 5% above the national average. Getting multiple quotes is the best way to ensure a fair price.
Do builder prices include materials in South Gloucestershire?
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.