Your ADU questions, answered.

An Additional Dwelling Unit (ADU) is a second, self-contained home on the same lot as your main house. It has its own kitchen, bathroom, sleeping area and entrance. In Ontario, ADUs include basement suites, attached suites, above-garage suites, garden suites and laneway suites. They're a legal, increasingly encouraged way to add housing, income and flexibility to an existing residential property without changing the neighbourhood's character.

We take on all five common Ontario types: basement suites, attached suites (additions), above-garage suites, detached garden suites and laneway suites. We work in custom, prefab-panelised and modular approaches, choosing whichever best fits your lot, access, timeline and budget. The right type is confirmed during your feasibility review.

We serve homeowners across Ontario, with concentrations in Toronto, the GTA, Hamilton, Niagara, Waterloo Region, London, Ottawa and surrounding communities. Because rules and incentives vary by municipality, every engagement begins with a property-specific feasibility review for your exact address.

In most cases, yes. Ontario's Bill 23 permits up to three residential units on most urban residential lots, and several municipalities now allow four. Lot size, setbacks, servicing capacity, conservation authority jurisdiction, and heritage designations still apply. A feasibility review confirms exactly what's buildable on your lot before you commit.

Bill 23, the More Homes Built Faster Act (2022), allows up to three units on most urban residential lots without requiring a minor variance, provided they meet the building code and local rules. It also reduced or removed certain barriers like parking minimums in many municipalities, making ADUs faster and cheaper to add than before.

Yes. Our design partners prepare permit-ready drawings, and we submit the building permit application, respond to municipal comments and coordinate inspections through to occupancy. We handle City Hall navigation as a core part of the service.

Most packages include a property survey, zoning review, site plan, architectural drawings by a BCIN-qualified designer or architect, structural details, an SB-12 energy summary, HVAC heat-loss and duct design, a servicing plan and an electrical load assessment. Depending on your lot and suite type, you may also need a fire-access route, conservation authority, heritage or tree permits, an HCRA builder licence number for a new detached suite, and a septic permit; see the permit-paperwork checklist.

For new detached garden or laneway suites, yes: the builder must hold an HCRA licence and the home is covered by Tarion's new-home warranty. DivineADU works only with HCRA-licensed builders for new detached suites, and that builder contracts with you directly. Basement and attached suites are renovations and do not require HCRA licensing.

Ontario's tiny home guidance sets a combined minimum living area of roughly 17.5 m² (about 188 sq ft). In practice, comfortable, rentable suites are considerably larger, but that figure is the legal floor for a habitable dwelling.

Sometimes. If your lot is near a floodplain, ravine, wetland or watercourse, the local conservation authority may have jurisdiction and require approval before building. We flag this during feasibility so there are no surprises later.

As estimates: basement suites typically run $60K–$120K, attached suites $80K–$180K, above-garage suites $100K–$200K, garden suites $150K–$400K+, and laneway suites $200K–$450K+. Your actual cost depends on size, finish level, servicing and site conditions. We provide a clear budget envelope after the feasibility review.

Cambridge offers up to $10,000, Mississauga exempts the second and third unit from most municipal charges, and Waterloo charges no City development charges on the first two units. London's 2026 ARU construction grants (up to $45,000 affordable / $20,000 standard) and permit-fee waiver are fully allocated and closed (permits issued Apr 29 to Sep 7, 2026). A repayable ARU loan remains available. In Burlington, ARU fee waivers ran until Dec 31, 2025, and the forgivable loan program closed Oct 1, 2025. Confirm current fees with the City. Barrie offers 50% off ARU building permit fees for applications submitted Jan 1 to Dec 31, 2026; full rebate if final inspection is within 12 months of permit issuance (no later than Dec 31, 2027). Availability changes, so we confirm what applies to your municipality.

Common routes include a home equity line of credit, a conventional refinance, the CMHC insured refinance product (which can fund up to four suites at up to 90% loan-to-value), and municipal grants where available. The best fit depends on your equity and goals; we can point you to the right resources.

For many Ontario homeowners, yes. A legal income suite can generate steady rent and add meaningful property value. But returns depend on your city, suite size, finish and costs. Our ROI calculator gives an illustrative picture, and a property-specific quote replaces estimates with actuals.

It varies by city, size and bedroom count. As a reference, TRREB's Q2 2026 GTA condo averages were $2,273 for a one-bedroom and $3,013 for a two-bedroom: market reference points, not guaranteed ADU rents, and suites are often smaller than the condos in those reports. Outside the GTA, expect lower figures, often $1,400–$2,400 for a one- to two-bedroom unit.

A legal, income-producing suite typically adds meaningful value. We estimate roughly $120K–$450K depending on the type. The actual uplift is property-specific and best confirmed by an appraisal once the suite is complete.

Generally no. An ADU is part of the same parcel of land, so it adds value but can't be sold on its own. The main exception is creating it through a Plan of Condominium, which can allow separate ownership but is uncommon and involves extra legal steps. Raise this goal early if it matters to you.

Multigenerational living is one of the most common reasons Ontario homeowners build. An ADU lets aging parents or adult children live close while keeping their independence and privacy. You can use it for family now and convert it to a rental later, which many owners plan for from the start.

Yes. Many homeowners use an ADU flexibly: a guest suite, a home office, or a studio, that's family space now and rental income later. We design for the use you have in mind while keeping future options open.

It depends on the type. Basement conversions are quickest at roughly 8–14 weeks of construction; detached garden and laneway suites take longer, often 20–34 weeks. Including design and permits, most projects run 6–14 months end-to-end, with municipal approval timelines being the main variable.

In most cases, yes. Detached garden and laneway suites are built in the yard with minimal disruption to the main home. Basement and attached suites involve more interior work; we'll set clear expectations for your specific project up front.

Every suite needs water, sanitary and hydro service. Detached suites usually trench these from the main home or the street, which is a common cost driver we scope early. Some lots have municipal services; others use septic. We assess servicing during feasibility.

No. DivineADU manages your project from feasibility to occupancy: design through our partner designers, permits, and choosing the builder. Construction is carried out by an independent licensed builder (HCRA-licensed for new detached suites) under its own contract with you. One point of contact, no gaps between designer, City Hall and builder.

Book a free 30-minute discovery call, or submit the quote request form with a few details about your property and goals. A senior advisor reviews your information and reaches out within one business day. Everything starts feasibility-first. We confirm what's possible before anyone commits.

We'll tell you honestly. The feasibility review exists precisely to catch this early, before you've spent meaningfully. If your lot isn't a fit for the suite you had in mind, we'll explain why and, where possible, suggest alternatives that could work.

Yes. The active federal tool is CMHC's insured refinance program. Effective January 15, 2025, it lets owner-occupiers refinance up to 90% loan-to-value on properties valued up to $2 million to fund the construction of up to four self-contained suites (the secondary suite must be a long-term rental, 90-day minimum). The proposed federal Canada Secondary Suite Loan Program never launched; Budget 2025 confirmed it will not be implemented.

Yes. Effective January 15, 2025, CMHC's insured refinance product allows you to refinance up to 90% loan-to-value (to a maximum property value of $2 million) to fund up to four secondary suites. It's one of the more powerful tools for owners with built-up equity who want to add multiple units.

Beyond the CMHC insured refinance, common routes include a home equity line of credit (HELOC), a conventional refinance, and municipal grants where available. The right mix depends on your equity, the suite type and your municipality's incentives.

Often, yes. A city grant, such as Cambridge's grant of up to $10,000, reduces your net project cost, while a CMHC insured refinance funds the balance. We help you map which programs your property qualifies for during feasibility, but always confirm current terms with each provider.

Very much so. A garden suite, basement suite or above-garage suite lets parents live close while keeping their own front door, kitchen and bathroom. It supports independence and privacy now, and many owners plan to convert it to a rental later, which preserves the long-term investment value.

In many Ontario municipalities, additional dwelling units must be on an owner-occupied property, and some grant or low-fee permit programs are explicitly for owner-occupied units (Guelph's $160 permit is one example). Rules vary by city and change over time, so we confirm the current requirement for your address during feasibility.

Yes, and it's a common plan. A well-built, code-compliant suite works equally as family space or a rental. Designing for both from the start keeps your options open without costly changes later.

It depends on local short-term rental rules. Many Ontario municipalities restrict short-term rentals or require the unit to be your principal residence; a common threshold treats rentals under 90 days differently from longer tenancies. Long-term tenancy is the simplest, most widely permitted use. Always confirm your city's short-term rental by-law before listing.

You can either include utilities in the rent or install separate metering or sub-metering so the tenant pays their own. Separate hydro metering is common for detached suites and is a design decision we scope early, since it affects both cost and tenant appeal.

On lots with septic rather than municipal sewer, an additional unit increases the load on the system. In regions like Durham, approval may involve the local health unit or an On-Site Sewage System (OSSO) review to confirm capacity. We flag septic considerations during feasibility so they don't surprise you later.

Adding a legal suite typically increases your property's assessed value, which MPAC (the Municipal Property Assessment Corporation) reassesses, and that can raise your property tax. The increase is usually modest relative to the rental income, but you should budget for it. Confirm specifics with MPAC and your municipality.

Yes. Once you add a rental or secondary suite, you should notify your insurer and typically add a rider or switch to a policy that covers a rented unit and landlord liability. Telling your insurer is important: an unreported suite can affect a claim. This is a quick conversation we recommend early.

Generally yes. Rental income is taxable, though you can usually deduct related expenses. There can also be implications for the principal-residence exemption when you sell. We're not tax advisors, so we recommend confirming your situation with an accountant; we're happy to design with your tax plan in mind.

If your lot is near a floodplain, ravine or watercourse, a conservation authority such as Credit Valley (CVC) or Toronto and Region (TRCA) may have jurisdiction and require approval before you build. This is an approvals matter rather than insurance, but it can affect siting and cost. We check conservation flags during feasibility.

Both are detached backyard homes. A laneway suite faces and is accessed from a rear public lane, which is why it's common in older urban neighbourhoods with lane networks (and why Ottawa calls it a coach house). A garden suite sits in the backyard without lane access. The right one depends on whether your lot has a usable rear lane.

They can. If your property is heritage-designated or in a heritage conservation district, you may need a heritage permit in addition to the building permit, and design may need to respect the property's character. We identify heritage status during feasibility and design accordingly.