This may seem a simple decision to start with, but there are many more different roof materials, and different options within each material, than you might think.
By far the most popular material for conservatory roofs, glass allows light to flood into a room, creating the light space that makes the conservatory a room for all seasons.
Plain Glass is not used anymore for roofs or windows. The minimum standard glazing is Low-Emissivity Glass. This is a glass that has a film or layer on it that helps to keep heat generated from your heating system inside the room, and is required by law as a minimum standard.
Low-E glass in a conservatory roof without any additional solarrated glass, is not a good idea. Only Solar Control Glass will reduce the heat build up in a conservatory.
Keeping a conservatory cool has 2 requirements:
Prevent as much incoming solar gain as possible
Circulate the air through the whole building as fast as possible
Solar control glass will always help reduce the amount of solar gain or heat build up from the sun. There are entry level solar glass products – which often contain self cleaning elements – that do not break the bank. High end solar products are sometimes triple glazed and are incredibly effective, but a bit costly!
Circulating the air inside a conservatory is equally, if not more important, than solar glass, The heat build up is in the air trapped inside the conservatory, as the hot air rises and slowly fills the room from ceiling to floor. Opening windows will help a little, but what is required is a pressure release in the roof where the hot air builds up.
On most conservatory designs, 2 or more, large roof openings should be designed in at the highest part of the roof. These ventilators only need to be opened a fraction to create a pressure release for all the hot air – with a couple of windows open at the bottom allowing the new fresher air into the conservatory.
Roof Blinds can also be an effective way to prevent solar gain in a conservatory. There are thousands of materials and designs for blinds and some of them are very effective, although you may be surprised at how expensive they can be!
Most architects and designers call a conservatory that has a tiled roof – a garden room.
Garden rooms tend to have windows and doors in the same configuration as a conservatory. This has the benefit of allowing a high level of light to enter the room, and maintains the open feel of a room between your home and garden. The tiled roof also offers protection from direct sunlight and is certainly more thermally efficient – making the garden room easier to heat in the winter.
The inside ‘feel’ of a garden room is more like a room in your home than a conservatory, although sometimes the ceiling can be vaulted or opened up as much as possible, and designed with roof lights to allow for some light entering through the roof. This will help keep the host room in the house as light as possible.
The main limitation with garden rooms is the height that is available. Tiled roofs require quite a steep pitch to remain water tight, and although there are some tiles that allow shallow pitches, it may mean you have to have a different tile on the garden room to that on the house.