Maintenance in NNN Leases — the Article That Prices the Deal

Every net lease’s value question eventually reduces to its maintenance article: who owns each building component’s problems, at repair scale and at replacement scale. It’s the clause that separates NNN from NN from absolute — and the one marketing packages reliably blur.

The component map

Read for explicit allocation of: roof (membrane repair versus full replacement — the classic split), structure (foundation, walls, slab), HVAC (repair, replacement, and the end-of-life question on 15-year equipment), parking (patching versus mill-and-overlay), and systems (electrical, plumbing, fire suppression). Strong leases assign each component at both scales; weak ones say “tenant shall maintain” and let litigation define the verbs. A one-page component matrix built from the actual lease is the cheapest underwriting artifact in any deal file.

Repair versus replacement — the money line

Tenants maintaining a component doesn’t mean tenants replacing it; plenty of paper obligates tenant repairs while replacement (capital) reverts to the landlord, sometimes with amortized pass-back provisions splitting the difference. On a 20-year-old building, that distinction is a five-figure line item per component. Price it: expected replacements across your hold, amortized against NOI — the double-net guide walks the arithmetic.

Diligence on the physical reality

Whatever the lease says, inspect as if you’ll inherit everything eventually — because at expiration or vacancy, you do. Roof cores and warranty transfers, HVAC age and service records, ADA and code exposure that surfaces at re-tenanting. Tenant-maintained buildings vary from meticulous (corporate programs with national vendors) to deferred-by-design (a franchisee’s final option period) — and the maintenance article tells you who should have cared, while the inspection tells you who did.