If this is a trading transaction as Mullet suggests I'd probably be inclined to sell the garden (WITH planning) to a company that I own. You'd then get a tax-free uplift on the value of the land with planning. And getting the profits on the development to arise in the company would save NI (cash paid out as dividends).
That said, it's by no means absolutely clear that this is a trading transaction. There's loads of guidance from HMRC on the "badges of trade". Start here. http://www.hmrc.gov.uk/manuals/bimmanual/bim20205.htm and consider each point.
1. Profit seeking motive - supports trading but by no means conclusive, so I don't think helps either side.
2. The number of transactions. Arguably there is only one transaction. Arguably also there are four.
3. Nature of the asset - property. That is typically either traded or investment, so I don't think helps either side.
4. Existence of other similar transactions. If you were to move on and buy another plot and build on it again, then it would definitely push this one into trading. (Or if you've done it before, or if you're a builder by trade.) If that's not you, then supports not trading.
5. Changes to the asset - supports trading.
6. Way sale carried out - supports trading.
7. Source of finance - I'm guessing you will have a bank loan, thus supporting trading.
8. Interval of time - a long time; supports not trading.
9. Method of acquisition - this was your home for many years; supports not trading.
So
Trading: 3
Not trading: 3
No help: 3 (although points 2 and 3 might just suggest more of a trading feel rather than less; or not.)
So it may in fact give you a capital gain, not a trading profit - in which case you wouldn't want a company.
mullet wrote:Which would leave only the original house and its smaller garden attracting private residence relief under the CGT rules. On that basis any improvement costs to the main house would be irrelevant since the overall gain would be exempt.
I am not sure I agree with this; there is no CGT-free gain on the profit arising from refurbishment - s224(3) TCGA refers.