If they got 800k-900k for each of the apartments, thats 12m-13.5m. Big pot to.start with retrofitting
Be aiming to fill the apartments with older bracket- 55+ sort of range who are sitting on houses now emptying. Give them some incentive to free up a house better suited to a family.
My Granny had that set up in her house out the Nire Valley when I was younger. Right into the 1970s. Big open fire in the middle of the cottage with an iron beam across the top of the fire to hang pots and kettles on.