Not every value-add strategy requires an extension. Poor circulation, undersized kitchens, awkward bathrooms and underused reception space can make a property feel smaller than it is.
Design around the end user
A reconfiguration should be tested against structure, services, fire safety, lease restrictions, planning context and the expectations of the local rental or resale market.
The best solution is not necessarily the layout with the greatest number of rooms. It is the one that improves function, light, privacy and marketability while remaining proportionate to cost and risk.