The board may require by ordinance that the county and the owner divide equally the reimbursement of any tenant of a building containing at least four residential units for amounts actually expended to relocate when the tenant has been terminated by 120 days’ notice given under § 55.1-1410 in order to carry out the rehabilitation of the building. The reimbursement shall not exceed the amount to which the tenant would have been entitled to receive under §§ 25.1-407 and 25.1-415 if the real estate comprising the units had been condemned by the Department of Transportation.