Extension & Self Build Cost Guide · Glasgow & Scotland · 2025

Extension & Self Build Costsin Scotland 2025.

This guide gives you a realistic framework for budgeting your home extension or self build in Glasgow and Scotland. Every project is different — but understanding the variables helps you plan with confidence before you speak to anyone.

We price every project individually — these are realistic ranges, not fixed quotes.

Ballpark figures for 2025

What Extensions CostIn Scotland.

Build costs in Glasgow and central Scotland typically range between £2,000 and £3,000 per m² depending on the type, complexity and specification of the extension. Here's how that breaks down by extension type.

Single Storey Rear
£40k – £90k

The most common extension type. A 20–30m² single storey rear extension in Glasgow. Price depends heavily on specification — standard finish vs high spec with bifolds, underfloor heating and stone worktops.

Double Storey
£60k – £150k

More space for your spend — the cost per m² of the upper floor is lower than the ground floor as foundations and roof are already being built. Popular for adding a bedroom and bathroom above a new kitchen-diner.

Kitchen Extension
£50k – £110k

Kitchen extensions cost more than standard extensions because of the fit-out — new kitchen, plumbing, electrics and often structural alterations to open up the existing space. Specification makes a huge difference here.

Garage Conversion
£15k – £35k

Generally the most cost-effective way to add space — the structure is already there. Cost depends on insulation, heating, electrics and the level of finish required.

Loft Conversion
£30k – £60k

Popular for adding a bedroom without losing garden space. Price varies significantly depending on the roof structure, whether a dormer is required, and the level of finish including en-suite.

Self build costs · Scotland 2025

How Much Does a Self Build Costin Scotland?

Self build costs in Scotland typically range between £2,000 and £2,750+ per m² of gross internal floor area — covering build only, before land, professional fees and VAT. A 150m² home would typically cost between £300,000 and £415,000 to build, depending on specification, site complexity and how the project is managed.

Standard Specification
£2,000–£2,300/m²

Good quality finish throughout — solid build with standard kitchen, bathrooms and finishes. The most common specification for self builders focused on value and liveability over luxury.

Mid–High Specification
£2,300–£2,750/m²

Higher spec finishes — better kitchen, upgraded bathrooms, underfloor heating, aluminium windows and higher insulation standards. This is where most of our clients land.

Bespoke / Architect-Designed
£2,750+/m²

Complex designs, premium materials, high-spec glazing, bespoke joinery and top-tier finishes throughout. No ceiling on cost at this level — specification drives everything.

What's not included in the m² rate

Land

Plot cost varies enormously by location. In and around Glasgow, expect to pay £80,000–£200,000+ for a serviced plot with planning permission.

Professional fees

Architect, structural engineer, building warrant, planning and project management fees. Budget 12–18% of build cost for professional fees and compliance.

VAT

New build self builds are zero-rated for VAT on labour. You can reclaim VAT on materials under HMRC's DIY Housebuilder scheme at the end of the project.

Why we don't give fixed rates

Every Project Is Different.We Price Accordingly.

The figures above are realistic starting points — but your specific project could sit anywhere within those ranges or outside them. Here's why, and what determines where your project lands.

Specification

Standard laminate flooring and basic fittings vs solid oak flooring, stone tiles and bespoke cabinetry. Specification is the single biggest variable in what your extension costs to fit out.

Structural complexity

Opening up walls into the existing property, removing chimney breasts, installing steel beams — structural alterations add significant cost that a simple per-m² figure won't capture.

Site conditions

Ground conditions, access restrictions, proximity to boundaries and drainage runs all affect cost. A straightforward site costs less than a restricted one — and you can't know until it's assessed.

What's included

Build cost is just the start. Architect fees (typically £3,000–£9,000), structural engineer, building warrant, planning fees and VAT all add to the total. A realistic budget accounts for all of these.

Design complexity

A simple rectangular extension is straightforward to build. Curved walls, rooflights, bifold doors, lantern roofs and complex junctions with the existing building all add time and cost.

Contingency

We always recommend holding a 10–15% contingency. Not because we expect to use it — but because unexpected conditions do arise and having contingency in place means decisions get made quickly, not delayed by budget pressure.

The honest answer

The Only Accurate NumberComes From Your Drawings.

Any company that gives you a firm price over the phone without seeing your drawings, assessing your site and understanding your specification is guessing. We don't guess. We review your drawings, visit your site and give you an accurate, fixed price for your specific project — so there are no surprises when work starts.

Apply to Work With Us →
Our fees

What We ChargeTo Manage Your Build.

Our project management fee sits on top of your build cost. Here's how it works — transparently, with no hidden extras.

Flexible support

Day Rate

Bespoke day rate
Tailored to your project and level of involvement

Ideal if you need support for a specific phase. You stay hands-on and only pay for the days we're actively working on your project.

  • Flexible — use us as much or as little as needed
  • Perfect for specific phases or stages
  • Suits clients who want to stay involved
Most Popular
Full management

Percentage of Build Cost

10–15% of build cost
Paid in monthly instalments — no large upfront fee

We manage everything from start to handover. Monthly payments mean no large upfront fee — transparent costs aligned to your project progress.

  • Complete end-to-end project management
  • Monthly instalments — no big upfront payment
  • One point of contact throughout
  • Weekly reports with photos and budget updates
  • Full snagging and professional handover
Apply to Work With Us →
Self build costs · Scotland 2025

How Much Does a Self Build Costin Scotland?

Self build costs in Scotland typically range between £2,000 and £2,750+ per m² of gross internal floor area — covering build only, before land, professional fees and VAT. A 150m² home typically costs between £300,000 and £415,000 to build.

Standard Specification
£2,000–£2,300/m²

Good quality finish throughout. Standard kitchen, bathrooms and finishes. Most common for self builders focused on value and liveability.

Mid–High Specification
£2,300–£2,750/m²

Better kitchen, upgraded bathrooms, underfloor heating, aluminium windows and higher insulation standards. Where most of our clients land.

Bespoke / Architect-Designed
£2,750+/m²

Complex designs, premium materials, high-spec glazing and bespoke joinery. No ceiling — specification drives everything at this level.

What's not included in the m² rate

Land

Plot cost varies by location. In and around Glasgow, expect £80,000–£200,000+ for a serviced plot with planning permission.

Professional fees

Architect, structural engineer, building warrant, planning and project management fees. Budget 12–18% of build cost.

VAT

New build self builds are zero-rated for VAT on labour. Materials VAT can be reclaimed under HMRC's DIY Housebuilder scheme.

Bespoke pricing

Want an Accurate NumberFor Your Specific Project?

The ranges on this page are a realistic starting point — but your project will have its own variables. For an accurate cost plan specific to your build, we can arrange a bespoke pricing exercise carried out by a qualified quantity surveyor.

What's included

Quantity Surveyor Cost Plan

A qualified quantity surveyor will review your architect's drawings and produce a detailed elemental cost plan — breaking your build down trade by trade so you know exactly what each element costs before a contractor is appointed.

  • Detailed elemental cost plan from your drawings
  • Trade-by-trade breakdown of your build cost
  • Contingency and risk allowances included
  • Carried out by a qualified QS
  • Carried out for a fixed fee — agreed upfront
Why it's worth doing

Know Your Number Before You Commit.

Most people go to tender without a cost plan and end up with contractor quotes they can't evaluate. A QS cost plan gives you an independent benchmark so you know whether the quotes you're getting are fair — and where to push back.

  • Know if contractor quotes are fair before you sign
  • Identify where specification can be value engineered
  • Set a realistic budget before work starts
  • Gives lenders confidence if you're using a self build mortgage
Enquire About a QS Cost Plan →