Yes, thats right, any associated costs should you choose to build yourself would be deductible from the gain made.
The address will be your normal tax office, marking both the envelope and the letter for the attention of the Technical team but if you do not have this address to hand then
HM Revenue & Customs
Pay As You Earn
PO Box 1970
If you set up and other vehicle, then you will incur a capital gain just by transferring the land to the limited company, so somewhat defeats the point!
And furthermore if this is just a one off project then it cannot be treated as a trade and therefore not trade income, so you would not be permitted to set up a limited company, or treat this as trade income for income tax purposes.
Although there are benefits from being charged corporation tax rates within a limited company, the fact you suffer capital gains just through transferring the land (at market value with planning permission) into the company, and then lose out of the entitlement of the annual exemption allowance (as this is only awarded to individuals) and then defendant on your annul income, should suffer 40% -50% tax on the drawing out of dividends, makes this a very costly exercise and certainly less tax efficient then just having this treated as capital gains - where you get the benefit of the annual investment allowance, and top rate of capital gains tax is 28%
So this is not a viable solution I am afraid, nor having it treated as trade income for income tax purposes as a sole trader or partnership.
Really, its just the hope that you can argue with HMRC that as the land is less than half an hectare (and you do not build yourself) might you stand a small chance of a ruling that no taxable charge arises.
Do feel free to ask any further follow up questions, but if, in the meantime you could rate the level of service received, it would be appreciated, as this ensures I am paid. And any feedback and/or bonus are always most welcome,