Upload these forms with your building permit application (unless they don't apply to your project):
- Owner Declaration Form (PDF) – most homeowners
- Schedule 1 Designer Form (PDF) – if a designer is involved
Build an ARU on the main floor or basement
Follow these steps to plan your additional residential unit project, apply for a permit and book inspections.
This information is for Residential Detached Houses, Semi-Detached Houses, Town/Row Houses containing not more than 2 dwelling units located in basements or on the main floor.
Tip: print this page and use it as a checklist.
On this page:
1. Plan your project
Before you start, review these steps and gather key details about your project:
- size and location
- materials you’ll use
- any features like stairs or railings
If your addition will be in a coach house visit the Additional Residential Unit coach house page.
For all other Additional Residential Units visit the standard ARU checklist page.
2. Check if you need a permit
You need a building permit if your ARU adds to your home’s footprint.
3. Confirm zoning rules
Before applying, make sure your proposed ARU follows all zoning and planning rules:
- distance from property lines (setbacks)
- proposed parking, and driveway dimensions
4. Confirm who can prepare your drawings
- Homeowner - for their own house (up to 2 units)
- Architect, Engineer, or BCIN-qualified designer
5. Prepare your drawings
Your site plan must show:
- lot size with dimensions
- all existing buildings or structures on the property
- parking spots (dimensioned)
- driveway and garage dimensions
- main and additional dwelling unit entrances
Your floor plans must show:
- existing and proposed construction
- wall details
- door sizes
- window sizes
- lintel sizes for new or altered load bearing openings
- ceiling heights
- insulation type and R-Value (if applicable)
- room areas and their names
- plumbing fixture locations
- smoke alarm and CO detector locations
- location of the ARU
- fire separation with fire resistance rating
- proposed exits
- key plans which detail other floors not included in the construction and include room names and areas
Structural Plans – detail any structural changes being made.
Elevations – Elevations are required detailing the existing and proposed elevation.
Cross Section – noting materials and dimensions
HVAC calculations - Part 6 design for HVAC and Mechanical – when each dwelling unit has 6 or more bedrooms.
6. Prepare your forms
Complete the forms that apply to your project.
Contact us if you’re not sure which forms you need.
Forms you need if you’re applying online
Forms you need if you’re applying in person
Bring these completed forms to the service counter on the 2nd floor of City Hall:
- Permit Application Form (PDF)
- Owner Declaration Form (PDF) – most homeowners
- Schedule 1 Designer Form (PDF) – if a designer is involved
7. Check permit fees
Permit fees depend on your project. HST does not apply.
- $350.00 per unit added
- $0.55/sq.ft. of area renovated
Pay when you apply:
- online – credit card only
- in person – cash, debit or cheque payable to City of Waterloo
We’ll start reviewing your application once payment is received.
8. Apply online
Submit your application through the building permit portal.
Upload your drawings and forms when you apply.
9. Wait for review
The typical time to review an application is 15 business days.
We may ask for more information before approval.
10. Get and display your permit
Once approved, your permit package will be available on the portal.
We’ll email you instructions on how to access it.
Print the full package and keep it visible at the work site.
11. Book inspections
Under the Ontario Building Code Act, you must book inspections before the work is covered.
Find the required inspections listed on your building permit under "Mandatory Inspections".
Book inspections through the building portal (find it on the left menu):
- the earliest you can book an inspection is the next business day
- you'll need your permit number