Office Downsizing in Chicago

The Loop and West Loop have spent several years working through the same exercise: a lease comes up, the occupancy data says the space is running at half its designed density, and the tenant gives back floors or relocates into a smaller and newer footprint. The financial model behind that decision usually treats energy as a line that scales with square footage.

It does not. Office energy cost is a function of a building's systems and a lease's allocation formula, and neither of those responds proportionally to a tenant occupying less of it. Understanding the actual mechanics is worth doing before the model is presented, because the gap between the projection and the outcome tends to be discovered a year later during an operating expense reconciliation, at which point it reads as a surprise rather than as arithmetic.

Three Separate Things Are Called "The Energy Bill"

In a Chicago office tower, a tenant's energy cost is assembled from sources that behave very differently:

• Base building energy recovered through operating expenses. Central plant, air handling, elevators, common area and garage lighting, and domestic hot water. This is billed to the landlord's ComEd account and allocated to tenants by a formula in the lease, usually pro-rata rentable square footage. It scales with your share of the building, not with your consumption.
• Tenant electricity, submetered or directly metered. Lighting and plug load in your premises. This scales with what you actually use, and it is where operational changes show up.
• Supplemental and after-hours charges. Dedicated cooling for equipment rooms, after-hours HVAC requested by the hour, and any separately metered special use. These are usually the most controllable and the most overlooked.

A downsizing moves all three, on three different schedules. Tenant electricity falls immediately when the floors are vacated. Supplemental charges fall only if the equipment they serve is actually decommissioned — a server closet left running for six months after the staff moved is a common and expensive artifact. And the operating expense allocation does not move until the reduced rentable square footage flows through a reconciliation, which under most Chicago leases means the following year.

The Base Building Does Not Get Smaller

This is the point that models miss. The chillers, pumps and air handlers in a tower are sized for the building, and they run on the building's occupancy schedule. If the building is 80% leased before your giveback and 72% after, the plant's consumption barely changes — but the cost of running it is now spread across less leased area, which means the per-square-foot operating expense for every remaining tenant goes up.

For a downsizing tenant, the net effect is a smaller share of a pool whose per-foot cost is rising. The reduction is real but partial. For a tenant that is staying put in a building where others are leaving, the effect is worse: same space, higher per-foot allocation, and no operational change to point to.

Either way, the operating expense clause is the document that governs the outcome, and it is worth reading with the same attention as the rent. What counts as an includable expense, whether there is a gross-up provision that normalizes variable expenses to a stated occupancy level, whether there is a cap on controllable expenses, and how energy is treated within all of that will determine what a giveback actually saves. Our broader treatment of the landlord and tenant split is in commercial real estate energy.

What You Can Actually Close

The only accounts a downsizing tenant can terminate are the ones in the tenant's name. Establishing that list is the first concrete step and it is frequently not what people assume.

Pull the payables file and identify every ComEd account and every retail supplier account billing to the entity, then map each one to a physical location and a lease. What surfaces in that exercise, reliably:

• The server room or MDF account. Supplemental cooling and dedicated power for an equipment room is often separately metered. When IT migrates to colocation or cloud, the room empties and the account does not close.
• The roof. Antennas, dishes and supplemental condensers on the roof deck can carry their own service. Nobody surrenders the roof.
• Storage and parking level meters. Small, durable, entirely forgettable.
• A prior address. Firms that have relocated once within the Loop in the past decade frequently still hold something at the old address. This is the single highest-yield finding in an office portfolio sweep.
• Sublease and swing space. Temporary space taken during a fit-out, held on its own account, and retained long after the move.

Each of these continues to bill a customer charge and, where demand-metered, a minimum or ratcheted demand, independent of consumption. The method for finding them is the same one described in a commercial utility bill audit: reconcile what you are paying for against what you actually occupy.

Illinois Supply: Do Not Terminate What You Can Amend

Illinois is a retail choice state, so a tenant holding its own accounts likely holds a supply agreement covering them. Downsizing is a volume event, and supply agreements are written with volume expectations.

Before the giveback, get three answers in writing from the supplier: how the reduced volume is treated against the contract's bandwidth, whether the removal of a premise from the agreement triggers termination liability or can be handled as a drop, and how a material change clause would be applied to a load reduction of this size. A supplier told in advance about a planned reduction has options that a supplier presented with a breach after the fact does not.

Terminating outright is usually the worst of the available choices, because most agreements price termination as a mark-to-market on unconsumed volume — which means a falling market turns a downsizing into a cash payment. Where the business has other Illinois locations, reallocating volume is generally available and generally cheaper. The relevant provisions are catalogued in the energy contract clauses that cost you money.

The Chicago Specifics

• ComEd delivery is demand-driven for commercial accounts. A tenant account that has reduced consumption but retained a peak — because a trading floor or a lab still spikes on occasion — will see far less relief than the kilowatt-hour reduction implies.
• Capacity and transmission tags are set on prior peaks. Northern Illinois sits in PJM's ComEd zone, where capacity and network transmission charges are allocated on load tags derived from prior-year peak hours. A summer giveback shows up in those charges at the following annual recalculation, not immediately.
• Winter givebacks preserve the summer tag. A tenant surrendering space in the first quarter carries a tag set the previous summer, at full occupancy, until the tags are recalculated. Anyone modeling a January giveback should assume no capacity relief that delivery year.
• Municipal aggregation does not cover commercial accounts. The opt-out programs many Illinois communities run are residential and small-commercial in scope, so a downsizing business generally has no default program to fall into and needs an affirmative supply decision.

Where Downsizing Genuinely Saves Energy Money

It saves where the tenant controls the load, and that is a shorter list than the square footage suggests but a more actionable one. Decommissioning a server room into colocation removes both the IT load and the supplemental cooling that served it, and in a professional services firm that is frequently the largest single controllable line. Consolidating onto fewer floors allows after-hours HVAC requests to be scoped to a smaller zone. Retiring the print and copy infrastructure that supported a 2015 headcount removes standby load nobody has looked at in a decade.

And the giveback itself does move the allocation, at reconciliation, in the year after it happens. That is a real saving. It is simply a different number than the one on the slide, and the time to correct the slide is before it is presented, not after the reconciliation arrives.