The Chicago Three-Flat Gas Guide: Three Meters, One Basement, Zero Labels
The two- and three-flat is Chicago’s signature building — and its basement holds Chicago’s signature gas mystery: a bank of meters, decades of undocumented work, and not one label telling anybody which line feeds which floor. Whether you own one, live in one, or are about to buy one, this is the guide to how gas actually works in a multi-flat: the meter bank, the per-account rules that strand buildings cold, the dead legs hiding behind plaster, and the paperwork that makes all of it manageable.
Anatomy of a Three-Flat Gas System
Downstream of the utility’s single service line, a multi-flat splits at the meter bank: one meter per account — typically one per unit, sometimes plus a house meter for shared laundry or a common boiler. From each meter, a dedicated line runs to its unit, snaking through a basement ceiling that’s hosted a century of renovations. Two facts define everything that follows. First: Peoples Gas owns up to and including each meter (their repairs are free — 1-866-556-6002); every inch past the meters belongs to the building owner and legally requires a licensed contractor. Second: in most of these buildings, no living person knows which line is which — the original fitter died decades ago and nobody wrote anything down. That single missing piece of information is behind half the multi-flat misery I get called into.
The Per-Account Rule: Why Only Some Units Come Back On
Here’s the trap, and it catches a Chicago owner every single month. A leak gets reported, the utility responds and shuts off the building or a line, and the owner — reasonably — calls their own account in once their repair’s done. Their floor comes back. The tenants upstairs stay cold for days, everyone blames the gas company, and nothing moves. The actual rule: each meter is a separate account, and each account requires its own passing pressure test on file before the utility restores it. The gas company isn’t being difficult; they literally cannot re-light an account without its test. The competent version of the process: a licensed fitter tests every line in one visit, produces a signed per-line affidavit for each, and coordinates all the account call-ins together — so a three-flat comes back as one building the next morning instead of floor-by-floor across a cold week. If you own multi-unit property, that sentence is the most valuable one on this site.
Trace It and Label It — Once
The permanent fix for the mystery bank costs almost nothing when bundled with other work: a fitter traces each line from its meter to its unit with instruments, tags the bank — first floor, second floor, third floor, house — and suddenly every future event changes character. Emergency shutoff? The right valve gets closed in seconds instead of guessing. Utility visit? Minutes instead of an hour of tracing. Selling the building? The labeled, tested, documented system reads exactly how a well-run building should. I include tracing and labeling free with any multi-line testing visit, because it makes every job after it faster — mine included.
Dead Legs: The Conversion Era’s Leftovers
Chicago’s flats have spent a century being reconfigured — three units to two, two to single-family, deconversions back again — and every reconfiguration risks leaving a dead leg: a capped branch still connected and still holding pressure, feeding a kitchen that stopped existing in 1987, buried behind newer plaster. They’re invisible to any visual inspection and they’re a standing leak risk at a joint nobody remembers to check. A whole-system pressure test flags every one (the section won’t hold if a dead leg’s cap or run is compromised, and tracing reveals branches that go nowhere), and the permanent fix is cutting the branch back to the main and capping it there. If your flat has a renovation history — and it does — assume dead legs until a test says otherwise.
Buying a Two- or Three-Flat? Test Before You Close
A multi-flat purchase multiplies the standard advice by the number of meters: the home inspection is visual, the piping history is undocumented, and the seller genuinely may not know what’s behind the walls. A per-meter pressure test inside your inspection contingency — $75–$150 per line, all lines in one visit — tells you exactly what you’re buying, and a failing line becomes negotiation leverage with a dollar figure attached instead of a surprise in your first winter. Ask for the meter bank to be labeled during the same visit and you start ownership already ahead of most landlords in the city.
Questions Multi-Flat Owners & Tenants Actually Ask
Who pays for gas piping repairs in my three-flat — can I bill tenants?
Building piping is owner infrastructure, full stop — bank, risers, unit branches, all of it. Tenant-owned appliance connectors are the only tenant-side exception. The complete responsibility map, including tenant rights and the escalation path, is in our who-pays guide.
I live in my own building’s first floor. Does that change my obligations?
Not for the piping — building infrastructure is the owner’s regardless of which unit the owner sleeps in, and your tenants’ heat and cooking gas remain essential services under Chicago’s ordinance. The upside: owner-occupants catch problems earliest, and early problems are the cheap ones ($120–$300 territory).
Our building got red-tagged. What’s the actual sequence to full restoration?
Licensed repair of whatever failed → pressure test on every line ($75–$150 each, one visit) → signed affidavit per line → every account called in to Peoples Gas together → utility re-lights each meter. Done right it’s a next-morning story; done account-by-account it’s a cold week.
There’s a fourth meter and we only have three units. What is it?
Almost certainly a house meter — shared laundry, a common boiler, or hallway heat, billed to the owner. It follows the same per-account restoration rules as the unit meters, and it’s the one most often forgotten in a restoration scramble. Label it.
Can one unit’s leak shut down the whole building?
Yes — if the utility can’t isolate the problem line (see: unlabeled banks) or the leak sits in shared space, they’ll err toward shutting more rather than less. A traced, labeled bank is exactly what lets an emergency stay one unit’s problem instead of everyone’s.
What does the full “make my building sane” package cost?
For a typical three-flat: pressure tests on all lines at $75–$150 each, tracing and labeling included free with the visit, and any repairs found priced from the published tiers (most fittings $120–$300). The majority of buildings get tested, labeled, and documented for a few hundred dollars — the cheapest insurance a multi-flat owner can buy.
One Visit. Every Line Tested. Every Meter Labeled.
Three-flat specialists across Chicago — per-line affidavits, coordinated restorations, dead legs found and removed, and a meter bank that finally tells the truth.
☎ Call (773) 200-2148Related guides: Who Pays for a Gas Leak in a Rental? · Why Gas Leaks Spike in Chicago Winters · All guides