Condo Flooring Rules, Explained: IIC, STC and Getting Board Approval

Replacing carpet with hard flooring is the single most common condo renovation — and the single most common reason boards reject applications. The rules aren't arbitrary: hard floors transmit footstep noise to the unit below, so buildings set minimum acoustic standards. Understand two numbers and one process, and you're ahead of most renovators.

IIC: the footstep number

IIC (Impact Insulation Class) measures how well a floor assembly muffles impact noise — footsteps, dropped keys, chair scrapes. Higher is quieter. Many condo buildings ask for a minimum somewhere in the IIC 50–60 range for the finished assembly; premium acoustic floors rate far higher. When a flooring product advertises an IIC rating, ask what assembly it was tested on — the number depends on the underlay and subfloor, not just the plank.

STC: the airborne number

STC (Sound Transmission Class) covers airborne sound — voices, TVs, music. Flooring contributes to it, though walls and construction matter as much. Some boards list an STC minimum alongside IIC; a strong acoustic underlay helps both.

The approval process, demystified

Almost every building requires a renovation application before work starts. The typical package: a description of the work, the product's acoustic test documentation, proof of the installer's insurance, and sometimes a WSIB clearance certificate. Add elevator booking and permitted work hours, and you can see why projects stall when owners discover the requirements late.

The shortcut

Ask about your building's rules before you fall in love with a floor. It's also exactly the part we handle at Floorrable: we confirm your building's requirements, match you to floors that clear them comfortably, and help prepare the paperwork your board wants to see — before anything is ordered. One approval, first try, is the goal.