Rear Extensions

Rear Extensions in Glasgow — The Complete 2025 Guide

Single-storey, double-storey or wraparound — everything Glasgow homeowners need to know about cost, planning, and design.

Why rear extensions are Glasgow's most popular project

Rear extensions are the single most common extension type we deliver across Glasgow — and for good reason. They unlock the back of the house, connect the kitchen to the garden, and dramatically increase usable family space without touching the streetscape. On Glasgow's traditional sandstone semis and Victorian terraces, a well-designed rear extension can transform a dark galley kitchen into a light-filled open-plan living hub.

Typical Glasgow rear extension costs (2025)

Glasgow rates have settled in 2025 after the post-pandemic spike. As a working baseline:

  • Single-storey rear extension (15–20m²): £35,000–£55,000
  • Single-storey with bi-fold doors and rooflights (20–30m²): £55,000–£80,000
  • Double-storey rear extension: £75,000–£130,000
  • Wraparound (rear + side return): £80,000–£140,000
Glasgow-specific cost factors
Sandstone matching, conservation area requirements (West End, Pollokshields, Dennistoun), and tenement structural work can each add 10–25% to base figures. Always price these in early.
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Estimate your Glasgow extension

Estimated cost range
£40,000 – £51,000

Includes labour, materials and standard fit-out. Excludes architect's fees, planning fees and building warrant.

Planning permission & permitted development

Scotland's Permitted Development Rights (PDR) cover most single-storey rear extensions on detached and semi-detached houses, provided you stay within the limits: under 50m² total, no higher than 4m, and not extending more than 3m from the original rear wall (4m for fully detached). The moment you're in a conservation area, on a flat, on a listed building, or going double-storey — you need full planning.

Conservation area considerations

Glasgow has 23 conservation areas including Glasgow West, Pollokshields, Dennistoun, and Strathbungo. In these areas, PDR is heavily restricted and Glasgow City Council's planners scrutinise materials, fenestration, and roof pitch closely. Sandstone matching, slate roofs, and traditional sash window proportions are usually required.

What works for Glasgow's housing stock

Victorian / Edwardian sandstone terraces

Glass-box rear extensions with structural steel and aluminium bi-folds work brilliantly against the original sandstone — the contrast is celebrated by planners. Watch out for shared rear lanes and party-wall agreements with neighbours.

1930s semis (South Side, East End, Bearsden)

The bay-window-and-pebbledash 1930s stock loves a wraparound that opens up the side return as well as the rear. Roof lights over the dining area are a budget-friendly way to flood the centre of the plan with light.

Modern detached (Newton Mearns, Bishopbriggs)

You usually have generous PDR allowances and good plot depth. Single-storey orangery-style additions with lantern roofs are the most popular spec.

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Frequently asked questions

Most single-storey rear extensions in Glasgow come in between £40,000 and £75,000 for a 20–25m² build. Premium finishes, complex foundations on sloping West End sites, or sandstone matching can push that to £85,000+. Use our calculator above for a project-specific estimate.