Owning your own home

We are looking at quotes to build an extension. after reading some t&cs we asked for JCT homeowners contract instead...this is the reply we got. xxx are the company

Hi dst,
We are unable to work to a JCT contract. As per the terms and conditions that Vicky sent through, the contractual setup that xxx work to is as follows: xxx are a project Management company and we arrange for contractors to work directly for yourselves. You make stage payments into a Client Deposit Account and you entrust xxx to manage your funds on your behalf. xxx release your funds to the contractors once we have checked each element of the project has been carried out to a high standard. Once the project has been finished and all invoices paid for, whatever sum is left in the Client Deposit Account is then transferred to xxx and this is our project management fee. xxx provide an overriding 10 year guarantee on the works and this forms part of the contract.

Any thought on this would be appreciated. They were the front runners but after this look to be out of the process.