Build Your Backyard Dream Home Across Ontario
From garden suites in Toronto to laneway houses in Ottawa, ADU Ontario helps homeowners design, permit, and build accessory dwelling units that add income, space, and long-term value to their property.
Permit-Ready Plans
Plans engineered to municipal ADU by-laws
Ontario-Wide Coverage
GTA, Ottawa, Hamilton & beyond
Fast Turnaround
Design to permit in 6–10 weeks
Custom + Modular
Site-built and prefab ADU options
Transparent Pricing
Fixed quotes — no hidden costs
ADU Options
Every Type of Accessory Dwelling Unit in Ontario
Ontario’s As-of-Right ADU rules now allow up to three residential units on most lots. Here’s how homeowners are making it work — and which option fits your property best.
Accessory Dwelling Units
The complete guide to ADUs in Ontario — what they are, how they add value, and how the province’s As-of-Right rules apply to your property.
Learn MoreAdditional Dwelling Units
Ontario now permits up to three residential units on most lots as-of-right. Here’s how Additional Dwelling Units work and which option fits your home.
Learn MoreGarage Conversions
Turn an attached or detached garage into a fully-permitted living space. Lower site prep costs mean a faster path to move-in ready.
Learn MoreBasement Apartment Requirements
Ceiling heights, egress windows, fire separation, parking — the full checklist for turning your basement into a legal secondary suite in Ontario.
Learn MoreIn-Law Suites
Self-contained living space for aging parents or adult children on your property. Learn what qualifies as an in-law suite under Ontario rules.
Learn MoreWhat Are ADUs?
New to the concept? Start here for a plain-English introduction to accessory dwelling units and why Ontario homeowners are adding them to their properties.
Learn MoreWhy ADU Ontario
Ontario’s Most Complete ADU Resource
We handle every step from feasibility study to final inspection — or give you the tools to navigate it yourself.
By-Law Experts
We track zoning and ADU by-laws across every Ontario municipality, so your project stays compliant from day one.
End-to-End Service
Design, engineering, permits, and construction under one roof. No hand-offs, no finger-pointing when issues arise.
Free Feasibility Review
Send us your address and we’ll tell you exactly what you can build before you spend a dollar on design or surveys.
Financing Guidance
From CMHC’s Secondary Suite Loan to HELOCs and construction mortgages, we’ll walk you through what actually works in Ontario.
Service Area
ADU Planning & Construction Across Ontario
We work with homeowners in every major Ontario city, and our guides cover by-laws for dozens more.
Blog
Learn Before You Build
Our in-depth guides cover Ontario ADU rules, costs, and design decisions — written for homeowners, not contractors.
What Makes a Basement Apartment Legal in Ontario?
Ceiling heights, fire separation, egress, permits — the key rules that turn a finished basement into a legal, rentable secondary suite anywhere in Ontario.
Read MoreAre In-Law Suites Legal in Ontario?
Short answer: yes, but the details matter. Here’s how in-law suites fit into Ontario’s secondary unit framework and what you need to get permitted.
Read MoreWhat Are Accessory Dwelling Units?
A plain-English introduction to ADUs — the different types, how they add value, and why Ontario homeowners are building them across the province.
Read MoreReady to See What You Can Build?
Send us your property address for a free, no-obligation feasibility review. We’ll confirm your ADU options, estimated costs, and timeline within two business days.