Solar Panels can be mounted either on or within the roof structure; in-roof would generally only be utilised during new construction as the PV system can replace the requirement to purchase roof covering. It is however advisable to mount the panels on framework above the roof, this keeps the panels cooler by improving air flow underneath the panels – therefore aiding efficiency. There are many different types of roof i.e. tiles, corrugated sheets (metal or fibre cement) etc. and consequently there are many different types of fixing methods. Before any installation work is undertaken structural surveys and wind loading calculations are conducted to ensure integrity. Alternatively, the PV system can be ground mounted; multiple panels are mounted on posts secured into the ground at predetermined intervals.