Who pays for major maintenance - me or the tenant?

By default the landlord. Under Article 16 of Law 26/2007, major and structural works — AC/HVAC, plumbing, water heaters, wiring, roofing — are the owner's responsibility, while tenants cover minor upkeep such as light bulbs and blocked drains, often under an AED 500 threshold set in the contract. Clauses forcing tenants to fund structural or AC replacement are unenforceable.