Scotland regional cost guide

House Extension Cost in Glasgow

Current 2026 national benchmarks adjusted with the transparent UK Home Costs Scotland planning model, plus worked Glasgow examples.

Last reviewed: 1 September 2026 · 0.95× regional model · Methodology

Modelled cost per m²£1,700–£2,850 / m²
Planning context£34,200–£57,000 for a modelled 20m² example
This page does not claim to measure observed contractor prices in Glasgow. It starts with dated UK benchmarks, applies the stated UK Home Costs modelling assumption and rounds the result for early budgeting.

Calculate your extension cost

Extension cost per m² in Glasgow

Current UK benchmark£1,800–£3,000 / m² before VAT
Glasgow modelled range£1,700–£2,850 / m²
Regional factor0.95× · 5% below the national planning baseline

Extension cost by size in Glasgow

Each row multiplies the current £1,800–£3,000 per m² national benchmark by floor area and then applies the same Scotland factor.

10m² extension£17,100–£28,500
15m² extension£25,650–£42,750
20m² extension£34,200–£57,000
25m² extension£42,750–£71,250
30m² extension£51,300–£85,500
40m² extension£68,400–£114,000
50m² extension£85,500–£142,500

What can change a real Glasgow quote?

  • Floor area and number of storeys
  • London and regional labour rates
  • Steelwork and structural changes
  • Kitchen or bathroom installation
  • Glazing and door specification
  • Finish level, access and contingency

Local planning considerations

Scottish projects can have different regulatory and grant contexts, so check current official rules alongside the cost estimate where relevant.

  • Scottish building standards and scheme rules should be checked separately from any England-and-Wales guidance linked elsewhere on the site.
  • Tenement or managed-flat work can add common-property, access and approval considerations beyond the physical installation cost.
  • Traditional masonry and older fabric may need specialist repair specifications that are not represented by a simple regional multiplier.

How the regional model works

The 0.95× factor places this planning estimate 5% below the national planning baseline. We keep that modelling assumption separate from the dated national benchmark so users can see exactly which part comes from an external source and which part is UK Home Costs modelling.

Sources

Checkatrade

House Extension: Cost Breakdown 2026

Published / checked: June 2026

Used for: Extension cost-per-m² benchmarks and common add-on costs

View source ↗
Office for National Statistics

Construction output price indices

Published / checked: 13 August 2026

Used for: Construction price trend and update checks

View source ↗

Frequently asked questions

How much does a house extension cost in Glasgow in 2026?

Our modelled Glasgow planning rate is about £1,700–£2,850 / m², based on the current national £1,800–£3,000 per m² benchmark and the Scotland regional factor. This is not an observed city-wide quote average.

How much is a 20m² extension in Glasgow?

Applying the same regional model to the current national benchmark gives about £34,200–£57,000 before VAT for a straight-line 20m² example. Structural work, glazing, kitchens, bathrooms and access can move a real quote outside that range.

Why is the Glasgow estimate different from the UK benchmark?

UK Home Costs applies a 0.95× Scotland planning factor, which places the model 5% below the national planning baseline. The factor is our modelling assumption rather than an external city price index.

Does the extension figure include VAT and professional fees?

The national benchmark used here is stated before VAT. Do not assume architect, structural engineer, planning, building-control, party-wall or specialist survey fees are included unless a contractor quote says so explicitly.

Compare extension cost across the UK