Am considering buying victorian semi. Normally would have two beds/bath on first floor and I would wish for loft conversion to provide 3rd bed/ensuite. However, current owner has converted front bed into roof space so that it has staircase up to mezzanine. To reformat the way I’d like it would require moving staircase and reinstating the loft floor in order to provide the third bed I want. Seems could be complex and expensive. Or is this pretty straightforward?