Legal Suites in Calgary: How Drywall Helps You Pass Code (and Add Value)

In Calgary’s housing market, secondary suites are more than just a smart way to add space - they’re an opportunity to boost your property’s value and open the door to mortgage-supporting rental income.

To be approved by the City of Calgary, your suite needs to meet some pretty specific building code rules. And one of the biggest factors? Drywall. It plays a central role in meeting those standards and ensuring long-term comfort and safety.

What Makes a Suite Legal?

In Calgary, a suite is considered legal when it meets the City’s requirements for safety, soundproofing, ventilation, and separate access. The city has strict rules to make sure basement or secondary units are safe, livable, and comfortable for tenants.

Some of the key building requirements include:

• Proper soundproofing between units

• Safe, separate entry and exit points

• Fire and smoke protection measures

• Adequate heating and ventilation

• Compliance with zoning and parking bylaws

Drywall (and how it’s installed) plays an important role in checking off a few of these boxes, especially when it comes to soundproofing and sealing against smoke.

Soundproofing Isn’t Just Insulation

When it comes to legal suites, soundproofing is one of the most important code requirements. And it’s not just about stuffing some insulation between the studs, you need a proper system.

Here’s what the City of Calgary requires for sound separation:

• Joist spaces must be filled with at least 150 mm of sound-absorbing insulation

• Stud spaces also need insulation, and a resilient channel must be installed on one side of the separation, spaced 400 - 600 mm apart

• Ceilings and both sides of shared walls must be finished with at least 12.7 mm (½″) gypsum board

• The entire system must provide an STC rating of at least 43 (or ASTC 40)

Why resilient channels matter:

Resilient channels are thin strips of metal installed before drywall. They create a small separation between the drywall and the framing, which breaks the path of vibration. This is what stops footsteps, bass, and those sharp high-pitched sounds from transferring between units. Insulation alone can’t achieve this - it’s the combination of insulation, resilient channels, and drywall that makes a suite truly quiet and code-compliant.

Drywall Thickness & Smoke Seal

Another requirement is sealing against smoke. This is where drywall thickness makes a difference:

• The minimum is ½″ drywall on ceilings between units.

• 5/8″ drywall is always recommended - it’s denser, adds about 15 minutes of fire resistance, and does a much better job at blocking sound. (½″ boards are lighter and easier to install but are full of air pockets, which makes them weaker for soundproofing.)

Of all the areas in a suite, furnace rooms require the highest level of detail and effort to meet code. These areas must be framed, soundproofed, and drywalled tight to all penetrations. Because space is tight, it’s one of the trickiest areas to finish properly. Here, code only requires ½″ drywall and basic fire taping (Level 1 finish), along with access panels for any valves.

Why It All Matters for Your Home’s Value

Once a suite is legalized, you open the door to real financial benefits:

• Increased property value - Homes with legal suites often appraise higher.

• Mortgage helper - Rental income can offset monthly payments.

• Future flexibility - Legal suites make homes more attractive to buyers, since they offer options for multi-generational living or investment.
  

By meeting Calgary’s drywall, soundproofing, and smoke-seal requirements - you’re creating a safe and high-value space that people actually want to live in.

Ready to Build or Legalize a Suite?

All the code requirements - resilient channels, drywall thickness, furnace room sealing, can feel like a lot to sort through. We’re here to take that stress off your plate and handle it all the right way.

Contact us today to talk about your project and get a free estimate.

Or, learn more about our drywall expertise by visiting our Basement Drywall Services page.