What shared-services issues should I check before buying one half of a legal duplex in Ontario?

Before buying one half of a duplex, check exactly how services like water, hydro, and heating are metered and billed between the two units, since some older duplexes share a single meter or a heating system in a way that requires an ongoing cost-sharing arrangement with the other unit's owner rather than being fully separate. Also look into how major shared structural elements, such as the roof and foundation, are treated, since responsibility for their maintenance and repair may not automatically follow the same split as the utilities.

Ask whether there is a written agreement between the two unit owners addressing shared costs, access for repairs, and how disagreements get resolved, since without one, these practical issues are left to informal negotiation each time something comes up, which can become a recurring source of friction. If no such agreement exists, consider whether it would be worth putting one in place with the other owner after closing. Reviewing this during your due diligence period, with your lawyer's help interpreting what actually exists on title and in any prior agreements, avoids taking on an unclear shared-responsibility situation unknowingly.