Understanding ADUs: A Complete Guide for Ontario Homeowners

What is an ADU?

An Accessory Dwelling Unit (ADU)—also known as an Additional Residential Unit (ARU) in Ontario—is a self-contained living space located on the same property as a primary residence. These units have become increasingly popular as homeowners look for ways to maximize their property's potential, generate rental income, or create housing for family members.

Types of ADUs

There are four main types of ADU configurations available to Ontario homeowners:

1. Detached Standalone Units

A completely separate structure built on your property. This is our specialty at Kuzyn Builds, with models like The Paul, The Maria, and The Henry designed for modern living.

2. Interior/Basement Conversions

Converting existing space within your home—such as a basement or attic—into a self-contained unit with its own entrance, kitchen, and bathroom.

3. Garage Conversions

Transforming an existing detached garage into a fully functional living space with all necessary utilities.

4. Additions

Building an attached unit to your existing home that functions as a completely separate dwelling.

Ontario Regulations

The City of London actively encourages ADUs as part of its housing affordability strategy. Key requirements include:

Maximum of 4 total dwelling units on one residential lot
Each unit requires a separate entrance
Independent utilities (water, sewer, electrical) for each unit
Building permits required for all configurations
Rental license required if you plan to rent the unit

Cost Considerations

ADU costs vary significantly based on the configuration type:

Interior conversions: $75,000 - $150,000
Garage conversions: $80,000 - $160,000
Additions: $120,000 - $220,000
Detached units: $148,000 - $350,000+

Keep in mind that utility hookup costs (sewer, water, electrical) are additional and vary by property.

Benefits of Building an ADU

Rental Income: Generate monthly passive income from your property
Multi-generational Living: Keep family close while maintaining privacy
Property Value: Increase your home's overall value
Flexibility: Adapt the space as your needs change over time

Getting Started

If you're considering an ADU for your London, Ontario property, the first step is a property assessment to determine which configuration is best suited for your lot and goals. At Kuzyn Builds, we handle everything from design and permitting to construction and final inspections.