What is a glazed extension?
A glazed or contemporary extension uses large panes of glass, slim aluminium frames and modern cladding to create a bright room that contrasts with the original house. Frameless corners, structural glass roofs and minimal sliding doors are typical features.
How much does a glazed extension cost in Renfrewshire and Inverclyde?
In Renfrewshire and Inverclyde, a glazed extension typically costs £2,700–£4,050 per m² of floor area, including VAT at 20% (standard rate). For a typical 18 m² project that is roughly £48,500–£73,000. Building costs in Scotland are close to the UK average, so the figures for Renfrewshire and Inverclyde are close to our national guide. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (13 m²) | £35,000–£52,500 |
| Typical project (18 m²) | £48,500–£73,000 |
| Larger project (25 m²) | £67,500–£101,000 |
| Rate per m² | £2,700–£4,050 |
What moves the price most:
- Glazing size, specification and lead time
- Lighting and finishes
- Access for large glass panels
- Cladding material
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 glazed extension in Renfrewshire and Inverclyde?
Before anything is built in Renfrewshire and Inverclyde, we confirm which approvals apply in Scotland. In Scotland a single-storey extension is often permitted development (Class 1A): where any part is within 1 metre of a boundary, it can project up to 3 metres from the rear wall of a terraced house or 4 metres on other houses, with eaves no higher than 3 metres, an overall height of 4 metres and no more than half the front or rear garden covered. The rights do not apply in conservation areas or to flats, and a building warrant will usually still be 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.
We check this for your address before design work starts, so there are no surprises later.
What we handle
From survey to sign-off, the job normally involves:
- Cladding or render finish
- Contemporary design and planning drawings
- Foundations, walls and insulated roof
- Energy and overheating calculations where needed
- Electrics, heating and finishes
- Large-format sliding doors and fixed glazing
How long does it take?
Allow 12 to 16 weeks on site; glazing lead times can be 6 to 10 weeks. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in Renfrewshire and Inverclyde
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 Renfrewshire and Inverclyde include Paisley, Greenock, Newton Mearns, Renfrew, Barrhead and Johnstone.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about glazed extensions in Renfrewshire and Inverclyde
Do I need planning permission for a glazed extension in Renfrewshire and Inverclyde?
In Scotland a single-storey extension is often permitted development (Class 1A): where any part is within 1 metre of a boundary, it can project up to 3 metres from the rear wall of a terraced house or 4 metres on other houses, with eaves no higher than 3 metres, an overall height of 4 metres and no more than half the front or rear garden covered. The rights do not apply in conservation areas or to flats, and a building warrant will usually still be needed before work starts.
How long does a glazed extension take in Renfrewshire and Inverclyde?
Typically 12 to 16 weeks on site; glazing lead times can be 6 to 10 weeks. Design and approvals beforehand usually take 3 to 4 months.
Is VAT charged?
Yes, VAT at the standard 20% rate applies to extensions. Our guide prices include it.
How much does a glazed extension cost in Renfrewshire and Inverclyde?
In Renfrewshire and Inverclyde, a glazed extension typically costs £2,700–£4,050 per m² of floor area, including VAT at 20% (standard rate). A typical 18 m² project comes to roughly £48,500–£73,000. Your fixed price depends on the survey and drawings.
Is triple glazing necessary?
Not always. High-performance double glazing can meet the standards; triple glazing helps in exposed locations.
Can large glass panels be lifted in?
Some need a crane or glass-lifting robot. We plan access during design.