house sale with land split

[eddiecurrent]

12 years ago i purchased a house which came with 6 acres of grass land and 1 acre of woodland. (7 acres) all land and house on one title for 400k

I have lived in the house for 12 years.

a buyer has come along and wants to buy the house and land in two separate transaction. (I think buyers want to reduce their stamp duty bill?)
they want to pay 550k for the house and 80k for the land in two separate transactions.

I understand as the house has been my main residence it is not subject to CGT.

My question is would I have to pay CGT on the sale of the land in some way?

[maths]

A main residence in which you live plus up to 1.23 acres of surrounding grounds on sale precipitates no CGT on any resultant capital gain. A greater area of grounds may still fall within the exemption from the CGT charge but only if such grounds are required for the enjoyment of the property (very difficult to determine; HMRC District Valuer (DV) would be involved).

Any gain attributable to grounds which are in excess of the 1.23 acres is subject to a CGT charge.

This requires valuations to be carried out. So, for example, the original purchase price will be apportioned between the house plus acceptable surrounding grounds and the balance of the purchase price allocated to the excess (ie those not necessary for the enjoyment of the property) grounds.

Similar valuation apportionments are necessary on a sale.

Theoretically ALL the grounds or an amount in excess of the 1.23 MAY be accepted by the DV as for the enjoyment of the property (but don't hold your breath).

However, for CGT purposes, one contract should be for the house plus acceptable surrounding grounds and one contract for the balance.