III. That if, after such notice and hearing, the public agency determines according to the standards of the ordinance, code or bylaw that the dwelling under consideration is unfit for human habitation it shall state in writing its findings of fact in support of such determination and shall issue and cause to be served upon the owner thereof an order which, if the repair, alteration or improvement of the said dwelling can be made at a reasonable cost in relation to the value of the dwelling and the ability of the owner to assume such cost, requires the owner, within the time specified in the order, to repair, alter, or improve such dwelling to render it fit for human habitation or to vacate and close the dwelling as a human habitation; or if the repair, alteration or improvement of the said dwelling cannot be made at a reasonable cost in relation to the value of the dwelling and the ability of the owner to assume such cost, requires the owner, within the time specified in the order, to remove or demolish such dwelling.