Solar thermal heating systems are the perfect way to heat your hot water sustainably and efficiently. Using radiation from the sun a typical system can provide 50 to 70% of your annual hot water. However, the location of a system will play a vital part in its performance and efficiency.To help you evaluate your site and confirm whether or not it is suitable for a solar thermal, we have designed the following guidelines:To get the best possible performance from your solution it should be placed on a south facing surface (roofs usually) with a 45 degree tilt towards the sun. If you have an east /west facing roof, you can still have solar thermal but you would need to install a panel on each side of the roof to catch enough daylight throughout the day, so the cost would be slightly more.Solar thermal is a technology which provides hot water. Most conventional hot water systems can be connected to a solar thermal solution, with the addition of a new cylinder allowing an extra coil to heat your water, but only two types of combi boiler are compatible with solar thermal systems - Ferrolli or Alpha. If you have a combi boiler that is not a Ferrolli or an Alpha, you would need to replace it with a standard boiler and tank system to be able to support a solar thermal system. This would cost approximately £1800-£2000 in addition to the solar thermal installation cost.Although it is technically possible to heat small areas of underfloor heating with solar thermal panels, using a thermal store, we would not advise heating radiators with solar thermal as they are not capable of producing enough heat to keep up with the rapid pace radiators lose heat.Solar thermal systems are ideal for heating swimming pools. Solar thermal panels can be sized to suit any pool size from domestic indoor or outdoor pools through to large scale solar heated leisure centre pools.Although solar thermal systems are not normally heavy enough to cause structural problems, if your roof is in poor condition we would recommend that you undertake a structural survey before proceeding with your installation. If your roof is in need of repair it is worth doing this at the same time as your thermal installation to utilise the cost of the scaffolding.It is preferable to have your panels on the rear or sides of a building and not the public facing side as this avoids many planning issues.Not every site requires planning permission, but we would still recommend that you check with your local council first before proceeding with your project. Listed buildings have stricter rules so contact your local authority at the very start of your project to ensure that the installation will be approved.