Chris
Hi Martin, A ‘standard’ form of contract (whether RMB or some other) is generally just that, so it’s not a question of ‘may’ have a clause that says the price is fixed. Either it does or it doesn’t. Unless it’s a sort of ‘pick and mix’ type of form, with alternative wordings that you or the builder can agree to use.
But I don’t think the RMB form is like that. And in the 2011 version (not sure if there’s a later one that’s different) Clause 54 ‘Cost Fluctuations’ means it’s actually the very opposite of a fixed price contract.
So unless you or your solicitor have put in a Special Condition to overrule or amend that clause then my understanding is you will not have a fixed price contract. Whatever the builder tells you, like ‘don’t worry mate, we never really use that clause’, at the end of the day you’re just relying on his good nature.
Of course none of this relates to provisional items, which by their very nature are intended to go up or down according to the actual cost of the work, and variations which you ask for after the contract is signed.