Office: Group B occupancy. Types: low-rise (1-4 story), mid-rise (5-12), high-rise (>75 ft). Classes: A (premium, >$40/sf NNN), B (middle, $25-40), C (value, <$25). Construction: steel frame or reinforced concrete. Core: elevators, stairs, MEP shafts, restrooms. Shell: curtain wall, storefront, precast, brick. Tenant: open plan (250 sf/person) or private (150-200 sf/person). MEP: VAV HVAC, above-ceiling distribution, raised floor (tech-heavy). Budget: $200-$600/sf. Parking: 3-4/1,000 sf typical. Post-COVID: flex/hybrid driving demand for high-quality amenitized space.