What is a side return extension?

A side return extension fills the narrow passage that runs alongside the back addition of many Victorian and Edwardian terraced houses. It widens a galley kitchen into a proper kitchen-diner, usually with a sloping glazed roof to keep the room bright.
How much does a side return extension cost in Argyll and Bute?
In Argyll and Bute, a side return extension typically costs £2,250–£3,200 per m² of floor area, including VAT at 20% (standard rate). For a typical 12 m² project that is roughly £27,000–£38,500. Prices in Scotland sit near the national average for this kind of work, and the range for Argyll and Bute reflects that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (8 m²) | £18,000–£25,500 |
| Typical project (12 m²) | £27,000–£38,500 |
| Larger project (17 m²) | £38,000–£54,500 |
| Rate per m² | £2,250–£3,200 |
The biggest cost drivers are:
- Steel beams and propping of the back addition
- Access through the house for materials
- Moving drains and soil stacks
- Agreements with neighbours on shared walls
A guide range is only a starting point: the guide price tool gives an instant figure for your size, and a free survey turns it into a fixed quote.
Do you need planning permission for a side return extension in Argyll and Bute?
Here is how the rules work for a side return extension in Scotland. In Scotland a single-storey infill beside a back addition can be permitted development within the height and boundary limits, but not in a conservation area. A building warrant is needed before work starts.
In Scotland a building warrant is needed before work starts on most extensions, loft conversions and conversions. It is issued by the council’s building standards service. When the work is finished, a completion certificate is submitted and accepted by the council after inspection.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
What we take care of:
- Glazed or solid roof with insulation
- Written agreement with neighbours on shared walls
- Drawings and planning or permitted development check
- Written agreement with neighbours on shared walls
- Floor levelling, heating and electrics
- Foundations and drainage, including any build-over agreement
How long does it take?
Build time is typically 10 to 14 weeks on site. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in Argyll and Bute
Scotland’s housing ranges from sandstone tenements and villas to post-war and modern estates, and the building warrant system shapes how projects are planned.
Towns we cover in Argyll and Bute include Helensburgh, Dunoon and Oban.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about side return extensions in Argyll and Bute
How much space does a side return add?
Typically 1.5 to 2.5 metres of width along the back addition. It often turns a narrow galley kitchen into a family kitchen-diner.
How do you get materials in?
Mid-terrace houses often have no rear access, so materials come through the house. We protect floors and plan deliveries carefully.
Who approves a side return extension in Argyll and Bute?
Planning matters in Argyll and Bute go to the council covering your address, and the work needs a building warrant. We prepare and submit the applications for you.
How much does a side return extension cost in Argyll and Bute?
In Argyll and Bute, a side return extension typically costs £2,250–£3,200 per m² of floor area, including VAT at 20% (standard rate). A typical 12 m² project comes to roughly £27,000–£38,500. Your fixed price depends on the survey and drawings.
Is a glass roof too hot or cold?
Modern solar-control double or triple glazing reduces glare and heat loss. Building regulations also limit how much glazing you can have unless the design shows it performs well enough.
Do I need planning permission for a side return extension in Argyll and Bute?
In Scotland a single-storey infill beside a back addition can be permitted development within the height and boundary limits, but not in a conservation area. A building warrant is needed before work starts.
