What This Liability Means

Commercial office leases typically include HVAC service during 'normal business hours' — usually 8am-6pm Monday through Friday. Any heating or cooling outside those hours requires a separate, metered request at rates of $50-$150 per hour per zone.

Dollar Example: Law firm working evenings 3 days/week and Saturdays, 2 zones of HVAC at $75/hour

Real Dollar Example

ScenarioLaw firm working evenings 3 days/week and Saturdays, 2 zones of HVAC at $75/hour
Exposure$23,400/year in after-hours HVAC costs

3 evenings × 4 hours × $75 × 52 weeks = $46,800/year for evening use alone. Add Saturday costs and real exposure is $23,400-$35,000 annually.

Worst Case Scenario

A call center operating 24/7 in a Class A office building without a 24/7 HVAC provision: after-hours costs can exceed $5,000/month in large spaces with multiple HVAC zones.

Warning Signs in Your Lease

  • HVAC included 'during Building Standard Hours' only — any deviation is billable
  • No cap on after-hours HVAC rates — landlord can increase rates annually

How to Limit This Liability

  • Negotiate 24/7 HVAC inclusion in the lease for businesses that operate outside standard hours
  • Negotiate a fixed monthly HVAC charge rather than per-hour billing

Frequently Asked Questions

What are 'standard business hours' for HVAC in commercial leases?
Typically Monday-Friday 8am-6pm, Saturday 8am-1pm in some buildings. Evenings, Sundays, and holidays are usually after-hours. Some tech-leaning buildings offer extended hours but rarely 24/7 without additional cost.
Can I negotiate 24/7 HVAC into my lease?
Yes, especially if you're signing a larger lease. For small tenants, landlords may offer extended hours for a fixed monthly premium. For large tenants with leverage, 24/7 HVAC may be included in the base lease.
What is a 'supplemental' HVAC unit and how does it help?
A supplemental HVAC unit (dedicated mini-split or CRAC unit) in your space operates independently of building systems. You control it, pay the electricity directly, and avoid after-hours billing. Many tech companies install supplemental units to avoid after-hours charges.
Are after-hours HVAC costs included in CAM?
No — after-hours HVAC is typically billed separately, directly to the requesting tenant. CAM covers common area and standard-hours building systems. After-hours HVAC is a direct tenant charge not shared with other tenants.
What notice is required to request after-hours HVAC?
Most buildings require 24-48 hours advance notice for after-hours HVAC. Last-minute requests may be denied or billed at a premium. Establish a process with building management early in the lease term.