In relation to the agreement to adjudicate, where the contract is not one to which the Act applies, evidently it is unnecessary to adhere to the requirements of the Act when agreeing the rules that will apply.  In Khurana and another v Weber Construction Ltd [2015] EWHC 758 (TCC), Khurana was a residential owner and therefore the contract between the parties fell outside of the scope of the Act. There were no adjudication provisions in the contract. The parties fell into dispute and, partly as a result of poor dispute resolution provisions in the contract, they decided to adjudicate.  The parties decided to adopt the rules of the Scheme except they agreed, contrary to paragraph [ ] of the Scheme and section 108(3) of the Act, that the adjudicator’s decision would be final and binding.  Khurana subsequently commenced court proceedings to in effect overturn an adjudicator’s decision. The court dismissed the court action, holding that whilst the decision of an adjudication in a statutory form of adjudication is only temporarily binding, it was perfectly permissible for the parties to agree that the adjudicator’s decision in this instance was final and binding. 

http://www.bailii.org/ew/cases/EWHC/TCC/2015/758.html