Ferdinand, I probably shouldn't have thrown in such a complicated side issue.
As you say there are already plenty of taxes and payments made when permission is gained and I did consider it, although I am no where near as well informed on it as you are. I believe that the taxes aren't quite as much as you said, limited companied do not pay CGT and would only pay 20% corporation tax on a gain. An individual would pay 28% CGT. Personally I do not like the way that the tax system favours capital gains over income with lower tax rates, but that is another matter.
A few points I might make. In Edinburgh where I am large sites sell for for over £1m an acre, around £150,000 a plot for 3-4 bed houses. As prices increase the fixed costs become more palatable. At the ultimate end of the spectrum you can for example look at the Royal Mail's 8 acre site in Mount Pleasant London valued at around £150-200m. Even after costs this is a big uplift in value.
Ransom strips and access can easily eat up 25% of the planning gain. But these themselves are just a planning gain, sometimes deliberate, but sometimes sheer luck. The previous site I bid on had a massive payout to SP Networks who just happened to have a substation and some cables on the site. They will pay taxes on this profit, but frankly have done nothing to deserve the profit. Lots of wayleaves like this were simply given away historically when land had little value. This gain instead could be going to the local community.
So you are right, the gains are way less than they used to be due to S106(S75 in Scotland) and various other regulatory burdens. But there still can be large gains. Part of my point was with the shortage of building land, if the gains could be used locally, rather than going into general taxation, it may help the NIMBY brigade become more amenable to more houses being built. Something that is badly needed.
Edited after thinking more about it. I was really just thinking aloud.
I am not a fan of people making large planning gains, but equally taxing things rarely helps. Maybe a better solution would be to get more land available for house building. Then the value of land wold fall to more reasonable levels and the planning gains would be a lot less anyway.
Edited by AliG, 22 September 2015 - 09:48 PM.