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 in a coach house
Follow these steps to plan your Additional Residential Unit coach house project, apply for a permit and book inspections.
This information is for detached, semi-detached and town or row houses with up to 2 dwelling units where the ARU is in a coach house.
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
Visit the Additional Residential Units in basements and main floors page or the standard checklist page if your addition is not in a coach house.
2. Check if you need a permit
You need a building permit for an addition to an existing footprint that creates an additional residential unit.
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
The city’s updated zoning bylaw allows up to 4 units on a low-rise residential property.
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
- proposed coach house
- parking spots (dimensioned)
- driveway and garage dimensions
Foundation plan - material and depth, helical pile locations (if applicable)
Your floor plans must show:
- proposed construction
- wall details
- door sizes
- window sizes
- lintel sizes
- ceiling heights
- insulation type and R-Value
- room areas and their names
- plumbing fixture locations
- smoke alarm and CO detector locations
- proposed exits
- appliance/mechanical equipment
Elevations – Elevations are required detailing the existing and proposed elevation.
Cross Section – noting materials and dimensions.
HVAC calculations
Helical pile torque calculations and manufacturer's technical documentation - the design must be stamped by a professional engineer when supporting more than an unroofed deck.
Site servicing drawings – for questions, please email Alastair Duncan or Natasha Prepas-Strobeck.
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.
- $1.26/sq.ft. of area renovated
- finished basement: $313.60
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 10 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