BIM60080 - Measuring the profits (particular trades): land: trading transactions: builders
Where builders buy and resell land there is a special onus placed on them to show that the transaction is on capital account and not part of the trade, see Harvey v Caulcott [1952] 33TC159.
This does not mean that builders can never hold land other than as trading stock. It does mean that they have to point to evidence that it was not acquired as trading stock.