Thermal performance
A warm roof conservatory replaces a glass or polycarbonate roof with an insulated solid roof, cutting roof heat loss from around 2.6 W/m²K to approximately 0.15 W/m²K.
A warm roof conservatory is a conservatory with an insulated, tiled or slated solid roof in place of glass or polycarbonate.
The roof is built from a structural frame, rigid insulation between and over the rafters, a breathable membrane, battens and a lightweight tile or slate finish. Internally it is boarded and plastered like any room in the house, so it takes downlights, coving and paint.
A warm roof matters in Glasgow because the heating season is long, sunshine hours are low and the roof is the largest heat-losing surface of a conservatory.
Glasgow averages roughly 5°C in January, about 1,100 hours of sunshine a year and around 170 rain days. A glazed roof in that climate radiates heat away for most of the year, which is why so many Scottish conservatories are abandoned from October to April.
A warm roof achieves approximately 0.15 W/m²K, against roughly 2.6 W/m²K for polycarbonate and 1.6 W/m²K for a standard glass roof unit.
| Roof type | Approx. U-value | Winter comfort |
|---|---|---|
| Polycarbonate | 2.6 W/m²K | Unusable in winter |
| Standard glass units | 1.6 W/m²K | Cold, expensive to heat |
| Low-e argon glass units | 1.0 W/m²K | Usable with strong heating |
| Hybrid solid roof with glazed panels | 0.18 W/m²K | Comfortable year-round |
| Full insulated warm roof | 0.15 W/m²K | Comfortable year-round |
Daylight is retained by specifying roof windows or glazed panels within the insulated roof.
Most existing uPVC and aluminium conservatory frames carry a modern lightweight warm roof, because these systems weigh far less than traditional tiles.
We survey the frames, base and dwarf wall before quoting. Where the existing structure is not adequate we specify strengthening or a new ring beam, and state the cost in the quotation.
A conservatory roof replacement usually requires a building warrant in Scotland, because it changes the thermal envelope and the structural loading.
We confirm the requirement with your local authority and submit the application on your behalf.
A warm roof replacement takes five to eight working days on site for a typical Glasgow conservatory.
The room remains weathertight throughout: the old roof comes off and the new structure goes on within the same day.
A warm roof replacement in Glasgow costs between £8,900 and £16,000 depending on roof size, style and the number of glazed panels.
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