Home/Modular Homes by City/Richmond Hill
Serving Richmond Hill & York Region
Modular Homes & Garden Suites in Richmond Hill, Ontario
Factory-direct modular homes and backyard suites for Richmond Hill and York Region. Here's what Richmond Hill's garden-suite by-law allows in your backyard, what it costs, and the rules that apply.
What you can build in Richmond Hill
Full modular homes — from $175,696. 29 models from 560 to 1,405 sq ft, 1–3 bedrooms — factory-built to the Ontario Building Code and set on a permanent foundation (a real, permanent house, not a “trailer”).
Backyard suites (ADUs) — from $96,244. 7 compact models built for garden-suite and in-law-suite use, sized to fit what Richmond Hill's by-law allows.
All homes are CSA-certified (A277 modular / Z240MH manufactured), finished in the factory, and delivered ready for foundation and hook-up. What's the difference between modular, manufactured, and mobile? →
Find your backyard suite — 3 quick questions
We'll narrow the models that fit a typical Richmond Hill backyard allowance to the ones that fit your life. No email needed.
1 · Who's it for?
2 · What layout?
3 · What size feels right? (Richmond Hill lots typically allow up to ~750 sq ft)
Richmond Hill needs a 550 m² lot + 18 m frontage and Site Plan Control (≈10–14 extra weeks) — the strictest in the GTA. Your exact lot may allow more or less — get the real number for your address in seconds.
Check your exact Richmond Hill address →Can you put a garden suite (ADU) in your Richmond Hill backyard?
Often, yes — Richmond Hill permits a detached Additional Residential Unit on most serviced residential lots. The specifics, from Richmond Hill Zoning By-law 66-18 as amended (ARU amendments through 2025–2026):
| Max size | 90 m² (≈969 sq ft); detached structures capped at 40% lot coverage |
|---|---|
| Max height | 6.0 m (≈20 ft) |
| Setbacks | 1.0 m (≈3 ft) rear; 1.2 m (≈4 ft) interior side |
| Minimum lot | 550 m² (≈5,920 sq ft) area and 18 m (≈59 ft) frontage — the highest thresholds in the GTA |
| Parking | 1 dedicated space, in addition to your home’s parking |
| Process | Site Plan Control required (landscape, grading, and servicing plans by a licensed engineer) — typically adds 10–14 weeks |
| Conservation | Lake Simcoe Region Conservation Authority (LSRCA) |
Getting your building permit in Richmond Hill
An eligible lot still needs a building permit before anything is delivered. Here's how Richmond Hill's process actually works — verified against the Richmond Hill building department's own pages.
How do you apply for an ADU building permit in Richmond Hill?
Through Richmond Hill EnerGov Citizen Self Service (online permit portal) (application portal ↗). All residential building-permit applications can be filed online through the EnerGov Self Service portal and are processed and issued electronically after online payment by credit card. The City uses a two-stage intake: a pre-screening completeness review (reference number assigned, reviewed within about 2 business days), then the formal application with outstanding documents and payment due within 2 weeks of the confirmation email. Questions: building@richmondhill.ca or 905-771-8810. Richmond Hill's building-permit page ↗
- Confirm your lot qualifies under Zoning By-law 143-24 — ARUs are permitted wherever single-detached, semi-detached and certain townhouses are permitted (up to 3 ARUs per lot, max 4 units total, and no more than 2 ARUs in a detached accessory residential building), and the lot must be separately serviced by municipal water and sanitary sewer
- Clear the pre-approvals that apply to your property before the building permit: a site-alteration (grading) permit for infill construction over 400 sq ft, TRCA permission if the property is in a regulated area, a tree permit if you'll injure or remove a tree 15 cm in diameter or larger, and a site plan agreement if the property is in a site plan control area
- Prepare the drawing package with a qualified designer (BCIN) or architect/engineer — site plan referenced to a survey, floor plans, elevations, sections, structural layouts, and mechanical drawings with energy-efficiency calculations — or use the City's pre-approved detached ARU model plans (approx. 6.64 m x 5.47 m) with the Pre-Approved Reference Model Declaration Form to streamline review
- Apply through the EnerGov Self Service portal: pre-screening assigns a reference number and the Building Division checks completeness within about 2 business days, then you submit the formal application and pay the permit fee online
- The City reviews the application — house-class permits carry a 10-business-day service timeline — and you respond to any deficiency notices
- Once issued electronically, build to the approved plans and book the required inspections through construction; the Electrical Safety Authority (ESA) permit for electrical work is separate from the City permit
- Complete final inspections before occupying the new unit
What does a Richmond Hill ADU permit application need?
- Building Permit Application Form
- Schedule 1: Designer Information Form (BCIN, or architect/professional engineer stamp where applicable)
- Compliance with Applicable Laws declaration form
- Site plan referenced to a current survey — property lines, setbacks to lot lines and other buildings, existing/proposed grades and finished floor elevations
- Floor plans, elevations, sections and construction details, stamped/sealed by a qualified professional
- Mechanical drawings with energy-efficiency calculations (Energy Efficiency Design Summary, CSA F280-12 heat loss/gain and ventilation summaries)
- Engineered roof truss and floor system layouts (structural)
- Completed tree declaration form
- Proof of pre-approvals where applicable: site-alteration (grading) permit, TRCA permission, executed site plan agreement
- If using the City's pre-approved detached ARU model: the Pre-Approved Reference Model Declaration Form
How much does an ADU building permit cost in Richmond Hill?
Expect roughly $1,500–$1,600 in City building-permit fees for a typical ~600 sq ft (56 m²) detached ARU at the 2026 new-residential construction rate of $27.37/m² (plumbing inspection included) — an estimate only; confirm how the Building Division classifies a detached ARU and budget separately for the grading/site-alteration permit, any tree permit, and servicing connections.
| Building permit — new residential construction (Group C: single/semi/townhouse/duplex rate) | $27.37 per m² of floor area (2026 fees, effective Jan. 1, 2026; includes plumbing inspection services) — confirm the classification applied to a detached ARU with Building Services |
|---|---|
| Minimum permit fee (Part 9 residential) | $210.12 flat |
| Interior alteration to create an ARU inside an existing building (for comparison) | $10.40 per m² (2026 'Residential and Additional Residential Unit' alteration rate) |
| Residential drain and sewer connection (plumbing, storm + sanitary) | $196.61 flat per residential drain/sewer |
| Site-alteration (grading) permit | Required before the building permit for infill construction over 400 sq ft — fee and any grading deposit set separately; confirm the current rate with Development Engineering (905-771-8830) |
| Tree permit (if injuring/removing a tree ≥15 cm diameter) | Separate application under the Tree Preservation By-law — confirm the current fee on the City's Trees on Private Property page |
Under the Development Charges Act, an ARU within or ancillary to a new or existing single-detached, semi-detached or row house is exempt from development charges when the ARU's gross floor area is no larger than the primary dwelling's — Richmond Hill reported 102 ARU exemptions granted in 2024. Confirm your exemption with the City's Capital and Development Finance group (905-747-6313) before permit issuance.
How long does an ADU building permit take in Richmond Hill?
Ontario's Building Code requires a decision on a complete house-class application within 10 business days. The City publishes a 10-business-day service timeline for house-class permits, but that clock follows the pre-screening stage — completeness review takes about 2 business days and you then have 2 weeks to complete the formal application — so plan for the intake steps and any pre-approvals (grading, TRCA, tree) on top of the review window.
Worth knowing before you apply
- Municipal servicing is a hard gate: By-law 143-24 requires the lot to be separately serviced by municipal sewage works and a municipal drinking-water system — ARUs are not set up for private well/septic lots in Richmond Hill
- Oak Ridges Moraine limits (northern Richmond Hill / Oak Ridges): ARUs are not permitted in ORMCP Natural Core or Natural Linkage areas, and in the ORM Countryside and Rural Settlement areas only one ARU is permitted and it must be within an existing single detached dwelling — a detached backyard ARU is not the available form there
- Infill construction over 400 sq ft needs a site-alteration (grading) permit from Development Engineering BEFORE the building permit — build this pre-step into your schedule
- TRCA permission is required before the building permit if the property is within a Toronto and Region Conservation Authority regulated area
- Richmond Hill's Tree Preservation By-law requires a permit before injuring or removing any tree 15 cm in diameter or larger, and a completed tree declaration form is part of the permit submission
- The City offers pre-approved detached ARU model plans (approx. 6.64 m x 5.47 m, OBC-compliant) that streamline permit review — submit the Pre-Approved Reference Model Declaration Form to use them; custom designs need the full stamped drawing set
- The ESA electrical permit is separate — the Electrical Safety Code has additional requirements when adding an ARU, so budget for the Electrical Safety Authority process alongside the City permit
Fees and timelines are estimates from Richmond Hill's published schedules, verified July 9, 2026. Rates and processes change — always confirm current requirements with the building department before you apply.
Grants & financing in Richmond Hill
See every program → Ontario ADU Grants Directory
A modular or prefab home on a permanent foundation is financed like any house. CMHC Prefab Plus allows an insured mortgage with as little as 5% down on the first $500,000, with construction funds released in stages. How modular home financing works →
Thinking of the suite as a rental? Run the numbers →
Richmond Hill modular homes — FAQ
Can you put a garden suite in Richmond Hill?
Yes — on a lot that meets the minimum size (550 m² and 18 m frontage), with a building permit. Richmond Hill also requires Site Plan Control, which adds about 10–14 weeks.
How big can a garden suite be in Richmond Hill?
Up to 90 m² (≈969 sq ft), with detached structures capped at 40% lot coverage. Check your address for the specifics.
Can you put a modular home in Richmond Hill?
Yes. On land you own, a modular home on a permanent foundation is legal residential housing under the Ontario Building Code throughout Richmond Hill, subject to standard zoning and permits.
How much does a modular home or backyard suite cost in Richmond Hill?
Modular home models start at $175,696 and run to about $338,000 for the largest layouts; backyard ADU models start at $96,244. Site work, foundation, delivery, and permits are additional.
Can I get a mortgage on a modular home in Richmond Hill?
Yes — on a permanent foundation it is financed as real property, including via CMHC Prefab Plus (5% down on the first $500,000).
Local rules summarized from Richmond Hill Zoning By-law 66-18 as amended (ARU amendments through 2025–2026); verified by Modular Homes 400 and reviewed by James Clarke, REALTOR®. Always confirm current requirements with the City of Richmond Hill before you build.