Ontario's Building Code sets a minimum sound rating for the wall between attached Concord townhouse units — a real design floor, not silence. A retrofit that adds mass and seals the gaps sound sneaks through is what actually quiets it after move-in.
A detached Woodbridge home doesn't have this problem. A Concord townhouse does, because somewhere behind your drywall is a wall your neighbour's drywall is attached to as well — what builders call a demising or party wall. Hearing a TV, footsteps, or a conversation through it isn't automatically a sign anything is wrong; it's also not something you have to live with. The real question is where the code's minimum stops and your own retrofit starts, and who's actually on the hook for either.
What the Building Code actually promises you
Part 9 of the Ontario Building Code, in its fire-and-sound-control provisions (Section 9.11), sets a minimum Sound Transmission Class (STC) rating of 50 for the wall or floor assembly separating one dwelling unit from another — the same requirement that applies to a townhouse party wall. STC 50 is a lab measurement of how much a wall assembly blocks airborne sound at a range of frequencies; it's a genuine, code-enforced minimum, not a marketing number, and most builders meet it with a double stud or staggered-stud wall, insulation in the cavity, and drywall on each side.
Here's the part that surprises people: a wall that tests at STC 50 in a lab can still let through plenty of real-world noise in your actual townhouse. That's because sound doesn't only travel straight through the wall panel — it flanks around it, through shared electrical outlet boxes back-to-back in the same stud cavity, through HVAC ducting, through a gap behind a baseboard, or along a shared floor assembly. A code-compliant wall and a quiet wall are related but not the same thing, and that gap is exactly where a retrofit earns its cost.
Is this covered under Tarion, or is it on you?
If your Concord townhouse is still within its Tarion new-home warranty window, this is the first thing to sort out before paying anyone. Tarion's warranty treats ordinary sound between attached units as a normal feature of townhouse living, not a defect — a subjective "it's too noisy" complaint on its own is not a covered claim. What is potentially covered is a demonstrable failure to meet the Ontario Building Code's own sound rating for that wall — in other words, if the assembly as actually built doesn't reach STC 50, that's a code compliance issue, not a comfort preference, and it falls on the builder to fix within the applicable warranty year, not on you to retrofit. Confirming this usually means an acoustic test, which isn't something to assume one way or the other — ask Tarion or a qualified acoustic consultant before paying for a DIY fix on a problem that might not be yours to fix.
Condo or freehold: who actually owns the wall
Concord has both condominium townhomes and freehold townhomes, and that distinction decides who has to agree to any wall-opening work, the same way it does for a Concord balcony guard or door repair. In a freehold townhouse, you own your side of the party wall outright and no board has a say in what you do to it, though the wall is still shared structurally with your neighbour. In a condominium townhome, the declaration decides whether the demising wall is a common element, a common element of exclusive use to each owner, or part of each unit — and that answer is not the same from one Concord building to the next. Read your own declaration, or ask property management in writing, before booking a retrofit that opens the wall.
What a real retrofit actually involves
None of this requires rebuilding the wall from the studs out. The common, effective fixes stack in order of how much they disturb the existing wall:
- Seal the flanking paths first. Acoustic sealant around the baseboard-to-wall gap, foam gaskets or putty pads behind electrical outlet and switch covers on the shared wall, and sealing any gap where the wall meets the ceiling or floor. This is the cheapest step and often the one most skipped, even though sound finds these gaps before it finds the drywall itself.
- Add mass and decoupling. A second layer of 5/8" drywall applied over the existing wall with a viscoelastic damping compound (often sold as "Green Glue") between the two layers meaningfully cuts airborne sound without touching the structure. Mounting that new layer on resilient metal channel, rather than screwing it straight to the existing studs, decouples the new layer from the wall's vibration and does more for footsteps and bass-heavy sound than drywall mass alone.
- Check the ceiling and floor too. In a two-storey townhouse, sound often travels through the floor assembly between units as much as the party wall, especially impact noise like footsteps — worth addressing at the same time if that's the actual complaint.
Before you cut into the wall: the fire-separation catch
That party wall isn't only a sound barrier — in most Concord townhouses it's also a required fire separation between your unit and your neighbour's, usually rated for a set period under the same Part 9 provisions. Adding a layer of drywall on your own side generally only helps that rating, but removing drywall to install resilient channel, or cutting into the wall for any reason, has to leave the fire separation intact and properly sealed around every penetration when you're done. A straightforward add-a-layer retrofit typically doesn't need a building permit, but confirm with City of Vaughan Building Standards before any work that opens up the wall itself, rather than assuming interior finishing work is automatically exempt.
What it actually costs
As general estimates for the area, not a fixed Rhodex price: sealing flanking gaps alone — acoustic caulking, outlet gaskets, baseboard sealing on one wall — typically runs $300 to $600. A full retrofit adding resilient channel, a second drywall layer, and damping compound on one wall commonly lands around $1,500 to $3,500, depending on the wall's length, ceiling height, and how much finishing (paint, trim) it takes to blend the new surface back in. Addressing a shared floor or ceiling assembly adds separately to either range, and is a bigger job than a wall retrofit alone.
Quick answers
How much does it cost to soundproof a shared wall in a Concord townhouse?
Simple gap-sealing and acoustic caulking often costs $300 to $600. A full resilient-channel-and-extra-drywall retrofit on one wall typically runs $1,500 to $3,500, depending on the wall's length and ceiling height.
Do I need a permit to add soundproofing to a townhouse party wall in Vaughan?
Typically no permit is needed just to add a drywall layer or acoustic sealant over an existing wall. But that wall is also your fire separation from the unit next door, so confirm with City of Vaughan Building Standards before cutting into it.
Is a noisy shared wall covered under Tarion in a new Concord townhouse?
Only if the wall fails to meet the Ontario Building Code's own sound rating, not just because it feels thin. Tarion treats ordinary noise between attached units as a normal feature of townhouse living, so a subjective complaint alone usually isn't a covered claim.
Who is responsible for a shared wall in a Concord condo townhome — the owner or the condo corporation?
It depends on your declaration, which can make the wall a common element, a common element with exclusive use, or part of the unit. Read your declaration or ask property management before you assume either way.
Who can I call to fix a noisy shared wall in Concord?
Rhodex can send a vetted craftsman for the soundproofing work you're responsible for. Request a quote at rhodex.ca/get-a-quote.html and ask that the quote separate simple acoustic sealing from a full resilient-channel retrofit.
Sound travels through gaps, not just drywall
The code gives you a wall built to a real, enforceable minimum — it doesn't give you silence, and it was never meant to. Most of what actually makes a Concord townhouse wall feel loud is the flanking path, not the drywall panel itself, which is good news: sealing an outlet box and a baseboard gap costs a fraction of what rebuilding a wall assembly would, and often closes most of the gap on its own.
Related reading
- More home repair guides for Concord
- Balcony Guard or Door Repair in a Concord Condo or Townhome
- Do I Need Condo Board Approval for a Small Exterior Job in Concord?
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