Depends on the house/site – size, orientation, natural conditions, what is available to you and more importantly what are you prepared to do? we have looked at many projects and researched alternative technologies in-depth but at the end of the day the client has to realise that there is a considerable additional financial contribution required and long payback period – I suggest you speak to a specialist consultant or research it yourselves for your specific requirements – but don’t be dependant on the sales literature that the distributors will dish out and don’t assume that they are all the same!!:)