We must determine how they use various aspects of their home, which areas of the home are the most important to them in terms of where they spend the majority of their waking hours, which parts of the home are not that important to them, and how making modifications will enhance their overall quality of life in their home and the general enjoyment of living there.
It's important to learn what their home will not allow them to do that they feel is necessary. It might be constructing an additional room or rooms, reconfiguring or reallocating existing space, or enlarging of a particular space such as a kitchen, porch, bathroom, or family room by taking space from adjacent rooms or removing built-ins that restrict how the space can be used. Perhaps there is a hobby that cannot be pursued or enjoyed as much as they would like due to the way the current space is designed.
There might be general lighting issues, where the space that they want to use for a specific activity is too dark or insufficiently lit to allow them to use it effectively. Maybe there is not enough natural light available because the windows are not large enough or plentiful enough. It could be a wiring issue where the additional lighting that is needed or required cannot be supported or without more circuits or outlets.
We need to get people to reveal what they are interested in doing in their home that they presently cannot do at all or cannot do to the extent they desire - or perform it safely. Then, our challenge is to help them determine how this can be done and to gain agreement on doing it.
It might be that there are rather simple ways to accommodate their interests, such as clearing out storage items, moving furniture, or removing cabinets that might be infringing on a particular space. We might observe or detect other ways a space can be enlarged or improved by moving activities from one room to another or by installing pull-out or pull-down shelving, tables, or beds to be available when needed but essentially removed from the floor space when they are not needed or required by returning them to their storage positions.
Depending on the current layout of the home, their budget, and the characteristics of their homesite, adding a garage or auxiliary structure in the back yard - or enlarging or reconfiguring existing buildings - might provide the space they are seeking as well for their activities.