Leases: the operating system of the building

Every dollar a property earns flows through a lease. The fields that run daily operations: parties and guarantees, suite and square footage, term (commencement, expiration), base rent and escalations, the expense structure, security deposit, options and rights, insurance requirements, and obligations for maintenance and improvements.

Structures allocate expenses. In a triple-net (NNN) lease the tenant reimburses taxes, insurance and CAM on top of base rent; the landlord's income is close to net. In a gross (full-service) lease the landlord pays operating costs from a higher rent — sometimes above an expense stop or base-year amount the tenant tops up. Modified gross splits categories. Two $30/SF leases with different structures can differ by $8–10/SF in landlord economics.

Amendments change current terms without erasing history: the current expiration lives in the latest signed document, while older rent rolls preserve what was true when printed. Precedence — signed documents over summaries, newer over older — is how conflicting records get resolved.