No it’s not loose/loose, the builder gets a commitment for planning purposes.

Think about it in terms of a contract. If you rent your house and the tenant breaks the lease. You’re only entitled to compensation to the extent of your losses. If you rent the house back out immediately at a higher rent then you have no loss thus the tenant who breaks the lease is not liable for anything.

If the builder is able to turn around and find another buyer, then there’s no loss to him.