What are the different types of conservatory roof?

The three main types are: (1) Polycarbonate, the cheapest and lightest option, but gets hot in summer and cold in winter. (2) Glass: toughened or laminated glass panels, better thermal performance than polycarbonate. (3) Solid/tiled roof: insulated solid roof with tiles or slates, typically the best thermal performance and allows the room to be used year-round. Solid roofs typically require building regulations approval.

Do I need planning permission to replace a conservatory roof?

Like-for-like replacements generally do not require planning permission. However, replacing a glass or polycarbonate roof with a solid tiled roof may require building regulations approval (as it changes the thermal and structural properties of the conservatory). Some solid roof systems are self-certified by the installer. Always check with your local authority before proceeding.

What is the area of a typical conservatory roof?

A typical conservatory is 3m × 4m to 4m × 5m in plan, giving a footprint of 12–20 m². The roof area is slightly larger than the footprint due to the pitch, on a lean-to roof at 10°, the additional area is modest; on a Victorian or Edwardian roof with multiple pitches, the actual roof area can be 15–30% more than the floor area. This calculator uses the plan dimensions directly.

Does VAT apply to conservatory roof replacement?

Standard rate VAT at 20% applies to most conservatory roof replacement work. Some energy efficiency-related works (such as insulation) qualify for a reduced 5% VAT rate, but a full conservatory roof replacement is typically subject to 20% VAT unless you qualify for a relief. This calculator shows prices inclusive of VAT.

How long does a conservatory roof last?

Polycarbonate roofs typically last 10–15 years before yellowing and losing performance. Glass roofs can last 20–25 years with proper maintenance. Solid tiled roofs are built to last 30–50+ years with the same maintenance as a house roof. Upgrading from polycarbonate to glass or solid adds significant longevity and energy efficiency.

Updated 1 May 2026

Conservatory Roof Calculator · Free UK Cost Estimate 2026

Estimate the cost of replacing your conservatory roof, polycarbonate, glass, or solid tiled, based on your conservatory's dimensions.

✓ Free to use✓ 3 roof types✓ VAT included✓ 2026 UK prices

Conservatory Roof Calculator

Enter dimensions and choose roof type. Cost estimate appears instantly

Length (m)

Width (m)

Roof type

Estimated cost

£3,200.00 – £6,400.00

16.0 m² × £200.00–£400.00/m² incl. VAT

Conservatory dimensions

4m × 4m

Roof area

16.0 m²

Roof type

Glass

Cost per m² (low)

£200.00

Cost per m² (high)

£400.00

Estimated cost range

£3,200.00 – £6,400.00

2026 UK indicative prices including VAT at 20%. Actual costs vary by region, installer, and complexity. Always obtain 3 quotes before proceeding.

How the Conservatory Roof Calculator Works

Quick Answer: Conservatory roof costs are estimated by area (m²) multiplied by the cost per m² for each roof type. A typical 4m × 4m conservatory (16 m²) costs approximately: polycarbonate £1,200–£2,400; glass £3,200–£6,400; solid tiled £8,000–£16,000 including VAT.

Formula

Cost = Length × Width × cost per m² (by roof type)

e.g. 4m × 4m = 16 m² × £200–£400/m² (solid roof) = £3,200–£6,400

Worked Example: 4m × 4m conservatory, glass roof

Conservatory length4 m

Conservatory width4 m

Roof area16 m²

Glass roof cost range£200–£400/m²

Low estimate£3,200

High estimate£6,400

Prices include VAT at 20%. Actual costs depend on complexity, access, installer, and regional labour rates.

Roof Type Cost Comparison

Roof type	Cost per m²	Typical 16 m² total
Polycarbonate	£75–£150/m²	£1,200–£2,400
Glass	£200–£400/m²	£3,200–£6,400
Solid / tiled	£500–£1,000/m²	£8,000–£16,000

2026 UK trade prices including VAT. Prices vary significantly by region and installer, always get 3 quotes.

Frequently Asked Questions

Conservatory roof replacement costs depend on size, roof type, and complexity. As a guide for 2026 UK prices: polycarbonate replacement £800–£2,500; glass roof £2,500–£6,000; solid/tiled Guardian-style roof £5,000–£15,000. Most conservatories are 10–20 m², use this calculator to estimate based on your actual dimensions.