You'd have to look into implied terms - the contract is open-ended, not permanent, and can be terminated after reasonable notice. It might be better to think of it as a licence rather than a contract, as the bills would be primarily usage bills (electricity, gas, water, refuse etc). Again, a licence can be ended on reasonable notice.
At the absolute limit, it may be considered to be a tenancy under the Residential Tenancies Act, and subject to the notice periods specified therein. That would also be a reasonable guide for what would be a "reasonable notice" if we view it as a licence.