Open curtains and blinds and let natural light in. If painting is necessary, use white or off-white on all walls. Make an inspection, room by room and remove all clutter and make needed repairs. In short, the better the condition, the higher the value, most times considerably. The condition of the complex itself is crucial in determining value.
Individual owners can play an active role in keeping abreast of how the complex is operated.
Attending a board of directors or homeowners meeting will gain you insight into how the development is run and what the costs of operation are. If the market for cooperative apartments is active, an appraiser can value individual units with the sales comparison approach. However, value is influenced by the amount and terms of the mortgage financing that the corporation has placed on the building. That must always be considered and carefully weighed. The condition of the property, its size, location, and the amenities available to shareholders are all determinants of value.