Estimated reading time: 7 minutes
If you ask tenants what they would change about their rental unit, the answer is rarely about the finishes. Countertops are noticed at viewing. They stop being noticed within a week of moving in. What tenants live with, every day, is sound.
Noise between units is the most consistently cited quality-of-life complaint in multi-unit residential housing — in surveys, in maintenance requests, and in the conversations that happen at lease renewal when a tenant who would otherwise stay decides to leave. It is also the factor that receives the least attention at the design stage, because it is largely invisible at completion and its consequences are only felt once people are living in the building.
This is a solvable problem. It requires making the right decisions at the right point in the process — which is during design and construction, not after.
What proper acoustic separation actually involves
Sound travels through a building in two ways: through the air (voices, music, television) and through the structure itself (footsteps, furniture movement, impact noise). Addressing both requires deliberate design choices at the assembly level — the walls, floors, and ceilings that separate one unit from another.
Standard construction methods meet building code requirements, which set a minimum threshold for sound transmission. Meeting the minimum is not the same as building a building that tenants find liveable. The gap between a code-compliant wall assembly and one that provides genuine acoustic separation is not enormous in cost terms, but it requires specifying the right products, sequencing the construction correctly, and understanding where the critical junctions are — because a well-insulated wall connected to an uninsulated floor-ceiling assembly provides far less benefit than the specification suggests.
Resilient channel systems, mass-loaded vinyl, acoustic batts, and decoupled floor assemblies are all established products with well-documented performance. The knowledge required to specify and install them correctly is not exotic. What is required is the intention to treat acoustic performance as a design priority rather than an afterthought.
Why unit configuration matters as much as materials
Insulation addresses the transmission of sound through assemblies. Configuration addresses the proximity of the activities that generate sound in the first place.
In a well-designed multi-unit building, the units are stacked or arranged so that living areas are adjacent to living areas, and bedrooms are positioned away from the shared interfaces. A practical example: in a duplex where the lower unit occupies the basement and main floor, and the upper unit occupies the first and second floors, the bedrooms in the lower unit sit in the basement — the quietest part of the building — while the bedrooms in the upper unit sit on the second floor, above the primary circulation of both units. The shared floor-ceiling interface, where the most transmission occurs, falls between the living areas of each unit rather than between someone’s bedroom and someone else’s kitchen.
This configuration is not accidental. It requires thinking about how people actually use the spaces — where they sleep, where they watch television, where children play — and arranging the building so that the noisiest activities in each unit are as far as possible from the quietest activities in the adjacent one.
The alternative — a configuration designed to maximise rentable square footage without regard for how the units will function in relation to each other — produces buildings where tenants can hear their neighbours clearly, where the most common complaint is noise, and where the tenancy turnover rate reflects the accumulation of that daily friction.
Designing and Building Profitable Multiplexes in Toronto
Acoustic separation and unit configuration are two of dozens of design decisions that determine whether a multiplex performs. Get the full guide to designing and building profitable multiplexes in Toronto.
The leasing and retention argument
The financial case for treating acoustic performance seriously is not complicated.
A tenant who is consistently disturbed by noise from an adjacent unit will leave at the earliest opportunity. The cost of that departure — vacancy period, re-leasing, turn costs, the time the unit sits empty while the market is surveyed — is consistently underestimated by owners who have not experienced it recently.
A tenant who lives in a building where the units feel genuinely private — where the presence of neighbours is known but not intrusive — is a tenant who has fewer reasons to leave. The renewal rate in well-configured, properly insulated multi-unit buildings is measurably higher than in buildings where acoustic separation was treated as a code compliance exercise.
This is the kind of return that does not appear in a pro forma at the design stage. It appears in the occupancy data over five years.
What this requires at the design stage
The decisions that determine how well a multi-unit building manages sound are made before construction begins. They are made when the structural assemblies are specified, when the unit layouts are drawn, and when the configuration of sleeping areas relative to shared interfaces is resolved.
Once a building is framed and drywalled, retroactively improving its acoustic performance is expensive and disruptive — and the results are almost always inferior to what proper specification at the outset would have produced. It is a problem that is easy to prevent and difficult to fix.
This is why the participation of people with operational experience in the design-build process matters. An architect can produce a floor plan that maximises floor area and satisfies the zoning requirements. A property manager who has managed hundreds of units and fielded years of tenant complaints knows, in detail, which configurations produce habitability problems and which do not. That knowledge belongs in the room when the layout is being drawn — not in a conversation after the first tenants move in.
“Acoustic separation is the rental feature that tenants feel every day and that landlords often discover only when a good tenant decides not to renew. The time to address it is at design. The cost of doing so is modest. The cost of not doing so is paid repeatedly, across every tenancy cycle, for the life of the building.”
Planning a multiplex conversion or new build and want acoustic separation and unit configuration handled properly from the start? Book a strategy call and get personalized guidance based on your property and project goals.
Frequently Asked Questions
Yes. Noise between units is consistently the most cited quality-of-life complaint in multi-unit residential housing, and it directly affects tenant retention. Buildings with genuine acoustic separation, beyond minimum building code requirements, see measurably higher renewal rates than buildings where sound insulation was treated only as a compliance exercise.
Reducing noise transmission requires deliberate design choices at the wall, floor, and ceiling assembly level — using products like resilient channel systems, mass-loaded vinyl, acoustic batts, and decoupled floor assemblies, and ensuring these are installed correctly at every junction. Unit configuration matters just as much as materials: arranging living areas adjacent to living areas, and positioning bedrooms away from shared interfaces, reduces the proximity of noise-generating activities in the first place.
A well-designed configuration positions bedrooms in the quietest parts of the building and away from the floor-ceiling interface shared between units, so that the noisiest activities in one unit are as far as possible from the quietest activities in the other. For example, in a duplex, placing lower-unit bedrooms in the basement and upper-unit bedrooms on the top floor keeps the shared interface between living areas rather than between someone’s bedroom and someone else’s kitchen.
