Buying a house jointly with parent

[ChrisL]

We are looking to buy a house with my father. We both have houses to sell & want a larger one with an annex or one we could divide to provide the right combination of proximity for support and privacy.

Please could anyone advise on the best approach & any potential pitfalls.

Particularly:
- how to avoid a heafty IT bill in the future that may cause us to have to sell up to pay it!
- will we have to pay CGT if the land is over half hectare when we sell (we're looking at 2-8 acre properties) - if so how is this 40% of the total gain - gulp!
- does it make a difference if we buy a cheaper house initially in our name & use dad's funds to extend for him.

Thankyou very much

Chris L