on dangerous ground
From a legal perspective, having a dojo on your own private property could put you in danger of losing everything in the event of a serious injury and a law suit. The insurance rate will be quite high and it still may not cover a major suit. In such an event, they could take your home, savings, assets — everything. That's why being incorporated and having a location on a commercial site is safer, from the legal perspective, because they usually can't go after your private assets.
Once again, I'm no expert in this area, but it seems to me that there are some serious hazards to be considered when having a dojo on your own private property.