How are after-hours HVAC charges supposed to work in a NNN lease?

Most NNN leases include a separate after-hours HVAC provision that charges tenants on a per-hour rate or based on metered consumption for any HVAC use outside standard building hours. These charges should appear on a separate invoice, not on the annual CAM reconciliation. If after-hours HVAC costs are being rolled into the shared CAM pool, they are being billed twice: once through the tenant's own after-hours invoice and once through the pro-rata allocation to all tenants.

Do other tenants in my building have the right to know if my after-hours usage is in their CAM charges?

Other tenants have the right to audit their own CAM charges and could surface the misclassification independently. From your perspective as the medical office tenant, you may actually benefit from the correction too: if your after-hours costs are in the shared pool, you are paying your pro-rata share of your own after-hours costs on top of the direct after-hours HVAC invoice you already receive.

Specific Tenant Type

Medical office: after-hours HVAC billed to all tenants as CAM

Medical offices often run outside standard building hours for evening appointments, early procedures, or on-call coverage. After-hours HVAC consumption benefits only the tenant using the space during those hours and should not be billed to the shared CAM pool. When it is, every tenant in the building subsidizes the medical office's extended hours. CAMAudit flags this as both a utility overcharge and a misclassification.

TL;DR

After-hours HVAC costs are often substantial for medical offices; if billed incorrectly to the shared pool, the medical office is also overpaying its own pro-rata share of its own after-hours costs.

Who this is for

Medical office tenants whose leases require them to pay separately for after-hours HVAC, or who want to verify that their extended-hours energy consumption is not being passed to other tenants through the CAM pool.

Who this is not for

Tenants in buildings where all HVAC costs are genuinely shared and metered at the building level with no sub-metering, and where after-hours usage by any tenant raises the building-level utility cost that is then allocated by pro-rata share.

What CAMAudit Checks in This Scenario

Rule 11

Utility Overcharge

CAMAudit flags utility charges that appear to include usage attributable to specific tenant spaces rather than genuine common area energy consumption.

Rule 12

Common Area Misclassification

The scan identifies HVAC charges tied to after-hours or extended-hours operation and flags them as potentially misclassified since they benefit only the specific tenant running after-hours.

What to Do Next

1Review your lease for the after-hours HVAC clause, noting whether it requires separate metering, a per-hour charge, or a different billing mechanism.
2Check your CAM reconciliation for any HVAC line items that appear unusually large relative to the building size or that include after-hours language.
3Compare total building HVAC costs on the reconciliation to utility bills if available to identify inflated figures.
4Upload your lease and reconciliation to CAMAudit to run the utility and misclassification rules.
5Request from your landlord the specific calculation showing how after-hours HVAC costs are isolated from common area HVAC costs in the billing.
6Dispute any after-hours costs billed to the shared pool that should be separately invoiced to the tenant using those hours.

Free scan · No account required

Run a Free CAM Audit Scan

Upload two PDFs. 13 detection rules. Under 5 minutes. Free.

Find My Overcharges See a sample report first

Next Best Step

Choose your next move

Scenario pages should bridge from diagnosis into the dispute path and audit proof.

What is a CAM audit?

Use the audit process if you still need to validate the billing error.

See the CAM dispute guide

Use the dispute playbook if the issue is already active.

Start Free Audit

Run the free audit once you are ready to quantify the overcharge.

Ready to skip the reading and document the overcharge directly?

Find My Overcharges

Relevant Tenant Types

Medical Office Dental Office

Related Scenarios

Restaurant tenant: kitchen exhaust billed as CAM charge Retail tenant: parking lot repaving billed as operating CAM Multi-location tenant: same CAM overcharge pattern across multiple properties

Related Resources

ResourcesCAM Overcharge Detection Guides ToolsFree CAM Audit Tools ResourcesLease Types and CAM Structures GlossaryCAM Glossary

Frequently asked questions

This page provides general educational information. It is not legal advice and may not reflect the most current law in your state. Consult a licensed attorney for advice specific to your situation.