Short answer: Manufactured, modular and mobile homes are all built mainly in a factory, but they are not the same thing. A modular home is made of three-dimensional modules joined on site and certified to the building code under CSA A277. A manufactured home is built to the CSA Z240 MH series, which the Canadian Home Builders' Association says is limited to one-storey, single-family detached houses. Mobile home is the everyday name for a manufactured home built to be moved. In Ontario, all three need a building permit and must meet the Building Code and zoning.
Key takeaways
| Question | Short answer | Source |
|---|---|---|
| Modular home | Three-dimensional modules built off site, assembled on the property | Ontario — Building a modular house |
| Manufactured home | Built to CSA Z240 MH; limited to one-storey, single-family detached houses | CHBA — Code Compliance for Modular Construction |
| Mobile home | Everyday term for a factory-built home made to be moved; a building if it stays put, is serviced and anchored | Ontario — Building Code, permits and inspections |
| Ontario certification | CSA Z240.2.1 or CSA A277, from a certified factory | Ontario — Building Code requirements |
| Foundations | Building Code footings or foundation, or anchorage under CSA Z240.10.1 | Ontario |
| Permit? | Yes, for any factory-built home installed as a building | Ontario |
Side-by-side comparison
| Modular home | Manufactured home | Mobile home | |
|---|---|---|---|
| How it is built | Volumetric modules in a factory, joined on site | Factory-built house, usually shipped whole or in sections | Factory-built home made to be moved |
| Main standard | CSA A277 certification to the local building code | CSA Z240 MH series | Usually CSA Z240 MH (as a manufactured home) |
| Storeys | One or more | One storey (Z240 MH scope) | Typically one storey |
| Foundation | Building Code foundation | Building Code foundation, or Z240.10.1 anchorage | Building Code foundation, or Z240.10.1 anchorage |
| Permit in Ontario | Yes | Yes | Yes, when it is a building |
Sources: CHBA; Ontario — Building Code requirements.
What a modular home is
The Government of Ontario defines a modular house as one built using one or more prefabricated, three-dimensional components or modules, built partly or completely off site in a manufacturing facility, then transported to a property and assembled there. Ontario notes that all modular houses are prefab, but not all prefabs are modular, and that a modular house still needs a municipal building permit and must meet the Building Code. CHBA says CSA A277 can certify buildings of all types and sizes, so modular homes are not limited to one storey. More detail: what is a modular home in Ontario.
What a manufactured home is
In Canada, manufactured home usually means a house built to the CSA Z240 MH series, titled Manufactured homes. CHBA says some jurisdictions reference or recognize Z240 MH, that it is limited to one-storey, single-family detached houses, and that most of its requirements mirror the National Building Code, with some differences such as increased requirements for durability during transport. People also search for terms like pre-manufactured small homes; whatever the label, the question in Ontario is which certification the home carries.
What a mobile home is
Mobile home is the everyday name for a factory-built home designed to be moved to its site, and it is often used interchangeably with manufactured home. For Building Code purposes, Ontario looks at use, not the label. Its tiny home guide says any structure on wheels can be considered a building if it stays in the same spot for a period of time, especially if it is connected to water, sewage and electricity, has exterior stairs and is fixed or anchored to the site. That generally does not apply to towed recreational vehicles and campers: if you can drive it or it needs a licence plate, it is likely not a building. For small units, see tiny home rules in Ontario.
CSA A277 vs CSA Z240
Ontario's Building Code requirements page says a factory-built home must meet one of the two key CSA certification standards in the Building Code for factory-built buildings:
- CSA Z240.2.1, Structural Requirements for Manufactured Homes. CHBA says the National Building Code references it and that it provides a deformation-resistance test for both site- and factory-built buildings.
- CSA A277, Procedure for Factory Certification of Buildings. CHBA calls it the primary standard for off-site construction compliance. It is an administrative standard: it sets the procedure for certifying that factory work meets the local building code, rather than technical rules of its own.
Ontario says factories building to either standard must be certified by an accredited organization such as CSA, Intertek or the Quality Auditing Institute, and warns that a home sold in Ontario but built elsewhere does not automatically meet Ontario's Building Code. CHBA says a certified building carries a label and a specification sheet, often near the electrical panel, listing the design loads, energy compliance and whether it passed the Z240.2.1 test.
Foundations and anchoring
Ontario says a factory-built home can be placed on footings or a foundation built to the Building Code, or secured to its site under CSA Z240.10.1, Site Preparation, Foundation and Anchorage of Manufactured Homes, which the Building Code references. CHBA adds that buildings and modules that pass the Z240.2.1 deformation-resistance test may be installed on point-load surface foundations under Z240.10.1, even where soil is subject to moisture movement. Whichever route you take, the foundation is built and inspected on site, not in the factory.
Permits and zoning in Ontario
Ontario's permits page says you need a building permit for a factory-built home shipped to your property, and you will not get one unless the project meets zoning and other applicable law. Once the home is on site, a municipal inspector checks things like the foundation or anchoring, outside stairs and water and sewage services. Ontario's tiny home guide also sets a Building Code minimum size of 17.5 square metres (188 square feet).
Where the home goes is a zoning question. For a second home in the backyard, the Planning Act (s. 16(3) and s. 35.1) stops zoning from prohibiting one unit in an ancillary building on most serviced urban residential lots, while your city still sets size, height and setbacks. Read additional residential units in Ontario and prefab and modular garden suites in Ontario. If the home is for a relation's primary residence, see the HST new housing rebate for modular homes and garden suites.
Modular X builds detached garden and laneway suites in modules, not manufactured or mobile homes. Every project starts with a free feasibility check of zoning, access, trees and servicing. Browse the garden suites hub, compare modular vs site-built garden suites or see the guides hub.
FAQs
Sources
- Government of Ontario — Building a modular house
- Government of Ontario — Build or buy a tiny home: Building Code requirements
- Government of Ontario — Build or buy a tiny home: Building Code, permits and inspections
- Government of Ontario — Build or buy a tiny home
- Canadian Home Builders' Association — Code Compliance for Modular Construction
- Planning Act, R.S.O. 1990, c. P.13, s. 16(3) and s. 35.1
Disclaimer: Figures cited are market estimates provided for information only and are not a quote. Municipal rules, fees, and programs change — always verify current requirements with your local authority. Modular X provides exact pricing only after a site-specific feasibility review.