The other half is owned by Tower Homes, a housing association that specialises in shared ownership. You pay them a reduced amount of rent for the second half. This allows people who cannot get a 250k mortgage get a 125k mortgage but still own a lovely new home. You can buy out the other half at a later date.

When you sell Tower Homes have a queue out the door for properties so you are obliged to sell to someone in that queue. There are no offers and they have to pay the independent valuation. Even if you have bought the other share and own 100% of the property you still have to sell to the queue and get the indepentdent market value for the property, so it takes the stress out of selling!