ADU (Additional Dwelling Unit)
Looking for ADU plans Ontario homeowners can trust? An ADU (Additional Dwelling Unit) adds valuable living space, but it must meet strict Ontario Building Code and municipal zoning requirements. We design fully code-compliant, permit-ready ADU plans that ensure your ADU is safe, legal, and approved without delays across Niagara and the Greater Golden Horseshoe.
ADU Types We Design Across Ontario
Options Available for Your Property
Basement ADUs / Secondary Suites
Basement suites offer flexible living space but must meet strict Ontario Building Code requirements for ceiling height, egress, fire separation, and ventilation. We design fully compliant layouts and permit‑ready drawings to help you build or legalize your basement ADU with confidence. Our team coordinates directly with your municipal building department throughout the review.
Backyard ADUs / Garden Suites
Garden suites create private, detached living space ideal for family or rental income. We prepare zoning‑aware, code‑compliant designs that meet municipal requirements for size, setbacks, servicing, and fire safety. Whether you need a garden suite for aging parents or extra rental income, our ADU plans Ontario clients rely on cover every structural and permitting detail.
Garage Conversions
Converting a garage into an ADU requires structural upgrades, insulation, fire separation, and proper heating/ventilation. We design clear, compliant plans that transform your garage into a safe, legal living unit. Our drafting team handles structural calculations, egress windows, and mechanical upgrades so your permit application moves through the city without setbacks.
Detached Rental Units
Detached ADUs provide independent living space with full privacy and strong rental potential. We design complete, code‑compliant plans that address structure, fire safety, servicing, and all permit requirements. This is one of the most requested ADU plans Ontario landlords ask us to design.
Retroactive ADU Legalization (As‑Built Drawings)
If your ADU was built without a permit, we document existing conditions and identify code deficiencies. Our as‑built drawings and corrective design solutions help you legalize the unit through a retroactive permit. Retroactive ADU plans Ontario building departments accept help you avoid orders to remove an unpermitted unit.
FAQ
We Are Here To Help You With Any Questions You May Have
What is included in ADU plans?
ADU plans typically include floor plans, elevations, sections, structural details, building code notes, and all drawings required for permit submission.
Do ADU plans need to be stamped by a BCIN designer?
Yes. In Ontario, ADU plans must be prepared or reviewed by a BCIN‑certified designer or a licensed architect/engineer.
How detailed do ADU plans need to be for a permit?
Plans must clearly show dimensions, layouts, fire separations, HVAC notes, plumbing details, and compliance with the Ontario Building Code.
Can I use generic ADU plans from the internet?
No. Ontario requires site‑specific, code‑compliant drawings tailored to your property, zoning, and municipal requirements.
Do I need a survey for ADU plans?
Some municipalities require a survey for detached ADUs. For interior units, a survey is usually not required.
Do ADU plans include zoning checks?
ADU plans follow the Ontario Building Code, but zoning must be confirmed with your municipality. We can guide you on what to check.
When we prepare ADU plans Ontario homeowners can submit with confidence, we cross-check every layout against current municipal zoning bylaws before drawings are finalized. This early review helps ADU plans Ontario projects avoid the delays that come from a zoning rejection after submission, since setbacks, lot coverage, and height limits are confirmed up front. Our team also verifies compliance with the Ontario Building Code so your secondary suite meets fire separation, egress, and ventilation requirements from the very first design pass.
How long does it take to get ADU plans?
Most first drafts are delivered within 1 to 3 weeks after the site measure, depending on complexity.
Can you design ADU plans for basement, garage, or detached units?
Yes. We design basement ADUs, garage conversions, and detached backyard units, all compliant with OBC requirements.
Do ADU plans include fire separation details?
Yes. We include all required fire‑rated assemblies, interconnected smoke/CO alarms, and code‑compliant safety notes.
Can you revise or update existing ADU plans?
Yes. We can update old drawings, correct code issues, or prepare as‑built plans for retroactive permits.