Reduce your risk in energy upgrades by using a performance based contract or some elements of it. This shares the risk of a project not creating the savings claimed or predicted between the owner and the supplier. Here's some simple steps to follow: Step 1: Decide on what works or projects you want to get done (lighting, heating, insulation, renewables). Step 2: Get some quotes (with guarantees for payback periods, insurance etc). Step 3: If a supplier tells you the system will pay itself back in 3 years, offer to pay over 3 times the savings you get each month for one year. This reduces your risk and will ensure the supplier is giving you correct information. Alternatively, hold back a percentage of the project costs (say 20%) and pay this over after 6 months once savings have been verified. For more details visit: https://en.wikipedia.org/wiki/Energy_Savings_Performance_Contract Don't ignore the ELEPHANT in the room.