Chicago Condo Flooring Rules: The IIC and STC Ratings Your Board Requires
Chicago's building code does not set a sound rating for the floor between two condos. Your association does, in its declaration and rules, and a floor that misses the standard can be ordered torn out at your cost. Here's what IIC and STC mean, why "lab" and "field" numbers are different, and how to get new flooring approved the first time.
Who sets the flooring sound rule in a Chicago condo?
Your condo association does, not the City. Chicago's building code did not adopt the sound-insulation section of the International Building Code, so the binding standard is whatever your declaration and board rules say, and those usually name a minimum IIC (impact noise) rating or a specific underlayment.
- Chicago building code minimum: none for sound between units (§14B-12-1206). None
- The model-code benchmark many boards borrow: IIC 50 in the lab, or 45 when field tested. IIC 50 / 45
- What actually binds you: your declaration, its schedules and the board's written rules. Your building
- The number that matters most: whether the rule is a lab rating or a field test of your real floor. Lab vs field
- The risk of guessing: most declarations let the board order non-conforming flooring removed at the owner's expense.
Does the Chicago building code set a minimum IIC or STC?
No. The Municipal Code of Chicago adopts most of the International Building Code, but Section 14B-12-1206 says it plainly: "The provisions of Section 1206 of IBC are not adopted." Section 1206 is the part of the model code that sets sound ratings between dwelling units, so there is no citywide IIC or STC minimum for the floor you walk on in a Chicago condo.
That does not mean anything goes. Under the Illinois Condominium Property Act, your board has the power "to adopt and amend rules and regulations covering the details of the operation and use of the property" (765 ILCS 605/18.4(h)). Flooring rules live there, and in the declaration itself. In a high-rise, they are some of the most strictly enforced rules in the building, because the complaint always comes from the neighbor below.
Where a building does quote a number, it is usually borrowed from the model code: the 2018 International Building Code, Section 1206.3, asks for an impact insulation class of at least 50, or at least 45 when the floor is tested in the field. This guide is part of our Chicago condo remodeling series.
What is an IIC rating, and what is STC?
IIC measures impact noise: heels, a dropped pan, a dog's nails on the floor above. STC measures airborne noise: voices, a TV, music. For a flooring change, IIC is the one that moves, because the finish floor and the underlayment beneath it are what a footstep hits first. STC between condos comes mostly from the concrete slab and the ceiling below, which a flooring project does not change. Higher numbers are better for both.
| Rating | What it measures | How it's tested |
|---|---|---|
| IIC (lab) | Impact noise through a floor-ceiling assembly | In a laboratory, on a sample assembly |
| FIIC / AIIC (field) | Impact noise through your floor, in your building | On site, with a tapping machine above and a meter in the unit below |
| STC (lab) | Airborne noise: voices, TV, music | In a laboratory |
| FSTC (field) | Airborne noise as built | On site |
The model code's own gap between lab and field (IIC 50 in the lab, 45 in the field) is a good rule of thumb: a floor usually tests a few points lower in a real building than on a data sheet.
Lab IIC vs field IIC: why a board rejects "IIC 70" on paper
Underlayment makers publish impressive lab numbers, and an IIC in the high 60s or 70s on a spec sheet is common. Those numbers are measured on a full test assembly, often a thick slab plus a finished ceiling underneath, that looks nothing like a bare Chicago high-rise slab. If your building's rule is written as a field result, a lab number proves very little on its own.
The engineer asked for "IIC 70". The rules asked for something else.
On a recent West Loop high-rise job, the building engineer emailed a request for underlayment "rated IIC 70 or higher". We asked where that number was written. It wasn't: the declaration's flooring schedule set a field IIC at least equal to a named cork system under wood floors and a named sound mat under every other hard surface, plus a specific perimeter isolation board at the walls. Agreeing to "70" in writing would have bound the owner to a standard the rules never imposed and a bare slab can't realistically reach. We submitted the test report for the actual assembly next to the building's benchmark instead. The same schedule let the board order any non-conforming floor removed at the owner's expense, so getting the paperwork right mattered more than any spec sheet.
The lesson we apply on every condo job: ask where the number is written, and whether it is lab or field, before anyone signs anything. Ask; don't argue. The building engineer is on your side once the standard is clear.
Hardwood, LVP or tile: what gets approved in a Chicago high-rise?
Almost every hard floor can be approved in a Chicago condo. What decides it is the underlayment and the paperwork, not the finish you fell in love with in the showroom. Here is how the common choices tend to play out with boards:
| Flooring | What boards usually want | Watch out for |
|---|---|---|
| Engineered hardwood | An approved cork or rubber underlayment, glued or floated as the rules specify | Nail-down installs over concrete rarely pass; the underlayment is what gets tested |
| Luxury vinyl plank (LVP) | A tested sound mat, not just the thin pad attached to the plank | Attached-pad planks often have no field test data your board will accept |
| Porcelain or stone tile | A sound-rated mat under the tile and grout | Tile is the loudest finish; the mat has to be in the approved assembly |
| Carpet | Usually allowed freely | Some buildings require a minimum share of the floor to stay carpeted |
Two details trip people up most. First, the perimeter: many declarations require an isolation strip where the floor meets the walls, because sound travels through any hard contact. Second, self-leveling and patching: in some buildings a thick pour over the slab triggers a structural review of the added weight. You can compare cork, rubber mats and finished samples side by side at our Lincoln Park design studio.
How to get new flooring approved by a Chicago condo board
Every condo floor we install goes through the same six steps, in this order:
- 1Read the declaration and the rules firstFind the flooring or acoustical section, often a schedule or exhibit at the back. Note the exact standard: a lab IIC, a field IIC, or "equal to" a named product.
- 2Ask where any number is writtenIf management or the engineer quotes a rating, ask which document it comes from and whether it is lab or field. A number that isn't written down isn't the standard.
- 3Choose the assembly, not just the floorPick the finish, the underlayment and the adhesive as one system, with a test report for that combination. Products such as Pliteq GenieMat or Regupol mats publish reports you can put next to the building's benchmark.
- 4Submit one clean packageProduct data, test reports, a floor plan showing where each finish goes, the perimeter detail, and your contractor's insurance certificate. Our condo permits and HOA approval guide covers the rest of the board package.
- 5Book the inspection before the finish floor goes downMany buildings want to see the underlayment and perimeter strip in place before they are covered. Build that visit into the schedule.
- 6Keep the recordsFile the approval, the product receipts and any field test. If a neighbor complains later, that folder is your defense.
- The ApprovalsCondo Remodeling Permits & HOA Approval in Chicago — the full board package, step by step.
- The CostsChicago Condo Remodeling Cost 2026 — what a condo renovation costs, room by room.
- The BuildingHigh-Rise Condo Remodeling in Chicago — elevators, work hours and building rules.
- The WoodHardwood Floor Refinishing Cost in Chicago — when refinishing beats replacing.
- The Kitchen FloorChoosing Flooring for a Chicago Kitchen Remodel — materials compared for the busiest room.
Chicago condo flooring FAQ
What IIC rating do Chicago condo boards require?
There is no single number: each Chicago condo association sets its own standard in its declaration and rules, because the City's building code does not set one. Many buildings borrow the model-code benchmark of IIC 50 in the lab or 45 in the field, and others require a floor at least as quiet as a specific named underlayment.
Does the Chicago building code require a minimum IIC or STC for condo floors?
No. Municipal Code of Chicago Section 14B-12-1206 states that the sound-transmission provisions of Section 1206 of the International Building Code are not adopted, so the binding rule for a condo floor is the association's declaration and board rules.
What is the difference between lab IIC and field IIC?
Lab IIC is measured on a sample floor-ceiling assembly in a testing laboratory; field IIC is measured in your actual building, with a tapping machine on your floor and a meter in the unit below. Field results usually come in a few points lower, which is why the model code accepts IIC 50 in the lab or 45 in the field.
Can I install hardwood floors in a Chicago condo?
Usually yes, over an underlayment your association approves. Engineered hardwood glued or floated over a tested cork or rubber mat is the most common approved assembly in Chicago high-rises; nail-down solid hardwood over concrete rarely passes.
What happens if my new floor doesn't meet the building's sound rules?
Most declarations let the board order non-conforming flooring removed and replaced at the owner's expense, which can mean tearing out an entire finished floor. Getting the assembly approved in writing before installation is far cheaper than fixing it afterward.
Who can adopt flooring rules in an Illinois condominium?
The condo board, under the Illinois Condominium Property Act, which gives it the power to adopt and amend rules covering the operation and use of the property after a meeting of unit owners. Flooring and sound rules are also often written into the declaration itself.
Get your new floor approved the first time
We read your declaration, match the underlayment to what your board actually requires, prepare the approval package and install the floor. We are pre-approved in 300+ Chicago condo buildings, so we know how these boards work.
Lincoln Park Design Studio: 2315 N Southport Ave (Mon–Fri 9am–7pm, by appointment) · HQ: 205 N Michigan Ave Suite 810 · (312) 544-9150 · assemblyserviceil.com
This guide explains how condo flooring rules work in Chicago; it is not legal advice. Your declaration and board rules are the final word for your building. Information current as of September 2026.