---
title: "Operating expenses (op-ex) — Class A Atlas glossary"
description: "The cost of running the building — utilities, maintenance, security, management."
canonical: https://classa.info/glossary/operating-expenses
pageType: glossary
lastUpdated: 2026-04-01T00:00:00.000Z
license: "CC BY 4.0 with attribution to Class A Atlas (https://classa.info)."
---

> The cost of running the building — utilities, maintenance, security, management.

## TL;DR

- The cost of running the building — utilities, maintenance, security, management.
- Op-ex includes utilities, building maintenance, cleaning, security, management fees, insurance, and minor capital items.

# Operating expenses (op-ex)

*Lease economics · Global*

## Short definition

The cost of running the building — utilities, maintenance, security, management.

## Full definition

Op-ex includes utilities, building maintenance, cleaning, security, management fees, insurance, and minor capital items. For a [Class A](/glossary/class-a) US office, op-ex typically runs $12-$20/RSF/year. In London the equivalent is the [service charge](/glossary/service-charge) — typically £8-£18/sqft. Op-ex is the most common source of post-lease disputes; insist on annual reconciliation rights and audit access.

## Why this matters for Class A leasing

Operating expenses (op-ex) is part of the lease economics vocabulary that institutional Class A occupiers, landlords, and advisers use across Global markets. Understanding it correctly affects how you read lease documents, model occupancy economics, and benchmark deal terms across cities. Class A Atlas tracks regional variation alongside the global standard so [cross-border](/topics/cross-border-expansion) occupiers can translate quickly.

## See also

- [Service charge](/glossary/service-charge)
- [Modified gross lease](/glossary/modified-gross-lease)
- [Base year](/glossary/base-year)

## Related guides

- [How to model occupancy cost per seat](/guides/occupancy-cost-per-seat)

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Citation: Source: Class A Atlas (https://classa.info/glossary/operating-expenses), updated 2026-04-01T00:00:00.000Z.