Estimate the cost of replacing your conservatory roof with polycarbonate, glass, or lightweight tiles
Replacing a conservatory roof is one of the most effective ways to transform an underused conservatory into a comfortable, year-round living space. Many UK conservatories built in the 1990s and 2000s have polycarbonate or single-glazed roofs that overheat in summer, freeze in winter, and create a deafening noise when it rains. A new roof can solve all three problems at once. The three main options are polycarbonate (budget-friendly but still prone to temperature swings), glass (excellent light transmission with improved insulation), and lightweight tiled systems such as Supalite, Leka, or Guardian Warm Roof (the best thermal performance, turning a conservatory into a true room extension). Each option has different costs per square metre, structural requirements, and Building Regulations implications. This calculator uses current UK trade averages to give you a realistic budget, average, and premium estimate for your project.
To estimate your conservatory roof replacement cost: 1. Enter the roof area in square metres. If you do not know the exact area, measure the floor of your conservatory (length x width) as a close approximation. Most standard conservatories range from 8 to 25 m2. 2. Select the new roof type. Polycarbonate is the cheapest option but offers limited insulation improvement. Glass provides excellent natural light with better U-values. Lightweight tiled roofs (such as Supalite or Leka) offer the best thermal performance and turn a conservatory into a proper room. 3. Toggle whether to include old roof removal costs. Most projects require removing the existing roof structure, which adds 500-1,200 to the total depending on the size and complexity. If your contractor has quoted removal separately, you can exclude it here. 4. Review the three estimates: budget (basic specification, competitive installer), average (mid-range specification, reputable contractor), and premium (high specification, specialist installer with extended guarantees).
The calculator uses UK trade average rates per square metre for each roof type: Polycarbonate: 150-350 per m2 (low to high specification) Glass: 300-600 per m2 (low to high specification) Lightweight tiled: 350-700 per m2 (low to high specification) Total cost = roof area (m2) x rate per m2 If old roof removal is included, a flat cost is added: Removal cost: 500 (budget) to 1,200 (premium) The price per m2 output shows the average rate including any removal costs, which is useful for comparing quotes from different installers. Rates are based on Federation of Master Builders (FMB) and Checkatrade published cost guides, reflecting installed prices including labour, materials, and VAT.
Inputs: Roof area: 15 m2, Roof type: Lightweight tiled, Include removal: Yes
Inputs: Roof area: 10 m2, Roof type: Glass, Include removal: No
Inputs: Roof area: 25 m2, Roof type: Polycarbonate, Include removal: Yes
All prices include VAT at 20% and are based on 2026 UK trade averages. Actual costs vary by region, with London and the South East typically 15-25% higher than national averages. Always obtain at least three written quotes from FMB or Checkatrade-registered installers. For tiled roof conversions, ensure the installer provides a Building Regulations compliance certificate, as structural calculations are required to confirm the existing conservatory frame can support the additional weight. Most reputable tiled roof system manufacturers (Supalite, Leka, Guardian) provide a 10-year guarantee on materials, while installer workmanship guarantees typically cover 5-10 years.