OK @swamp_rat, Just a couple more points on SIPPs from me and then I’m going to shut up as I’ve reached the limits of my knowledge:-
SIPPs are there to help you save for retirement, they aren’t just money making schemes. The government provides its contributions to help you fund your retirement, especially with the self employed in mind. BUT once you’ve put money in YOU CANT TAKE ANY OF IT OUT TILL YOU ARE AT LEAST 55. At least that used to be the situation – it might have changed but I don’t think so. Really not sure how this fits with buying a property and putting it in there – and certainly not with using SIPP money to pay for renovations.
You are clearly developing an elaborate scheme for using a SIPP to your advantage, that’s fine. BUT you really MUST talk to a SIPP specialist who can provide you with up to date and informed advice on your proposed scheme. You would be foolish in the extreme to embark on this based on inputs from a few people on an investment discussion board – doing so might lead you into making a very expensive mistake indeed. And not all SIPPs are exactly the same so you might need to talk with more than one.
There ARE no easy answers in this world. YOU NEED TO DO COMPREHENSIVE RESEARCH TO ENSURE THAT WHAT YOU WANT TO DO IS FEASIBLE. YOU SHOULD NOT MAKE ANY FINAL DECISIONS BASED ON THE INFORMATION THAT HAS BEEN PROVIDED HERE.
That said it is good to hear that you are interested in SIPPs and intend to take the matter further.