vat reclaimed on Self Build House now to be Holiday Lets

A client has built a new house, as they live in a tied cottage, and have reclaimed the vat as a self build earlier this year, but they now plan on using it for furnished Holiday Lets until they need it if and when the job finishes.  Is this a problem as it will be a business and therefore the vat should not have been zero rated by the builder or reclaimed.  Could the vat then have to be paid or are they ok.  Thanks

Jean