Hello Rhys,
VAT on installations of solar thermal installations, including ancilliary equipment, is already chargeable at 5% only. If your installer is charging you at 17.5% then they may be making a nice little extra, since they will only be required to forward 5% of the charge to HMRC. Zero rating would be better and would improve the payback, but perhaps not by as much presented in your analysis.
regards
Yes but I was looking at the DIY aspect. Wookey has said it all.
If a simple set of parts for a retrofit system ( as plug and play as possible ) could be put together, with no need to pay building control £170, and the vat man £200, take up might be just a little better and the self installs might be safer!!
The closest I could get to this was Navitron - the payback wasn't that important - but it played a part in prioritising.
If I had been really logical more insulation first, would have been a better option £ for £.
Still it makes me feel good every time oil prices go up 40%.
And I'd rather spend money on kit like this, than other forms of entertainment - most people don't and won't - till either Oil prices rise or installation costs, can at least be seen as a reasonable investment.
New build is very different - the payback over the life of the system and the house is virtually there already. All new houses should have solar or other renewables, and that is now happening. The 10% renewables required by many planning authorities, in new housing, can often best be met with solar.