Many smaller conservatories built in the 90s weren’t insulated properly, if at all. A single-glazed conservatory roof means that it will get too hot in the summer and too cold in the winter. Typically, these conservatories are only usable for a short time during the year.
A new roof is the biggest improvement to a conservatory. It makes the biggest change to the usability of the room. Switching to an insulated roof or better glazing makes a huge difference, and gives the room the potential to retain a comfortable temperature. A new roof adds a significant amount of value to a conservatory. The cost varies from £5,000 to £8,000, but a new roof can turn a conservatory from a greenhouse to a useable room.
For a small conservatory, underfloor heating is a better choice than radiators for a few reasons. Wall space is at a premium once the conservatory furnishings are added. Blocking a window or door with a radiator reduces the already limited available wall space.
In the summer, blinds are more useful than people realise on small conservatories. The roof of a conservatory is usually the biggest expanse of glass in the house. The roof of a conservatory can contain large open spaces where the sun is immediately gaining heat and transferring it to the interior of the conservatory. Blinds can help control heat gain by trapping air. Honeycomb and cellular blinds do this better than roller blinds.
A budget constrained full roof replacement leaves options for other changes. Wall mounted secondary glazing and improvements to door threshold draught proofing can improve a conservatory and extend its use. However, a full replacement can still be needed for better insulation.
See also: Glass Garden Rooms for Small Gardens