One Team From Property Review to Completion
Fourplex Builder Mississauga & The GTA
GrandBuild Homes has been building homes since 1995, with more than 100 homes delivered. As an experienced fourplex builder, we manage the project from the initial property assessment through design, zoning, approvals, construction, and completion.
- HCRA Licensed
- Tarion Registered
- 100+ Homes Delivered
We Check Fourplex Feasibility Before We Design
A fourplex only works if the property can support it. Before detailed design begins, we review the conditions that can affect whether the project is practical and approvable.
That includes:
- Zoning and permitted unit count
- Lot coverage, setbacks, and building height
- Servicing and separate utility metering
- Existing building conditions for conversions
- Fire separation, sound separation, and egress
- Parking and site access where applicable
For a fourplex builder Mississauga project, we assess the applicable Mississauga rules first. Projects elsewhere in the GTA are reviewed against the requirements of that municipality.
The goal is straightforward: understand what the property can support before you spend heavily on plans and construction.
What a Fourplex Build Includes
A fourplex is designed around four self-contained units, with each one providing its own living spaces and essential facilities. Depending on the property, the project may involve fourplex new construction or converting an existing home.
A typical build may include:
- Four kitchens and bathrooms
- Independent entrances and living areas
- Structural design and modifications
- Mechanical, electrical, and plumbing systems
- Construction to the Ontario Building Code (OBC)
The goal is to create four properly functioning residential units within one coordinated building, not simply divide an existing house into separate spaces.
Fourplex Construction or Conversion - Choosing the Right Approach
Fourplex New Construction
A purpose-built fourplex new construction project gives you the opportunity to plan the building around four units from the beginning. Unit layouts, entrances, mechanical systems, fire separation, and servicing can all be designed as one coordinated project.
For owners planning to hold the property as a rental or develop it for another purpose, we can assess the construction scope before the design is finalized.
Fourplex Conversion
If you already own a house, a fourplex conversion may be possible depending on the building and property. We look at the existing structure, floor area, ceiling heights, servicing, access, and the work needed to bring the building up to current requirements.
A conversion is not automatically the cheaper option. We compare the existing building against the scope of a new build so you can make the decision based on the actual work involved.
From Property Review to Permit Approval, Managed by One Team
Once the property review confirms what's workable, the project moves into design and municipal approvals.
Our process can include
- Property and zoning reviews
- Building design and permit drawings (BCIN)
- Structural and building-code coordination
- Municipal permit submission through the applicable ePLANS portal
- Building permit and required approvals
- Committee of Adjustment applications where a minor variance is necessary
- Construction and inspections
- Final Walkthrough
The approval route depends on the property. Where a project fits within the applicable as-of-right permissions, the process can be more straightforward. Where it does not, additional municipal approvals may be required.
Underpinning for Fourplex Basement Conversion
Some properties may require significant structural work to create the basement conditions needed for a fourplex conversion. If the existing basement does not provide sufficient height, underpinning may be required to safely lower the basement floor while maintaining the stability of the existing foundation.
The need for underpinning depends on the existing foundation, soil conditions, basement depth, and proposed four-unit layout. Identifying these requirements during the feasibility and structural review helps establish a realistic scope, budget, and construction plan before work begins.
Ontario Building Code Requirements for Fourplex Construction
Every fourplex construction project must meet the applicable Ontario Building Code (OBC) requirements. These can include structural safety, minimum ceiling heights, fire separation, egress, stairs, insulation, ventilation, and other life-safety requirements.
The exact requirements depend on the property's existing conditions and the proposed four-unit design. Reviewing the OBC requirements early helps ensure the project is properly designed, permit-ready, and accurately budgeted before construction begins.
What a Fourplex Costs to Build
Fourplex construction cost in Mississauga and the GTA depends on more than the size of the home. A few things specific to four-unit builds drive the price up or down
- Four kitchens and bathrooms
- Fire and sound separation between all four units
- Mechanical systems sized for four households
- Conversion vs. new construction, priced differently
- Site conditions, materials, and finish level
We scope the project after the feasibility review, then price it as a fixed, itemized number.
A cap rate and pro forma review, weighing that cost against expected rent, tells you whether it makes sense before you commit.
What Our Fourplex Clients Say
Areas We Serve Across Mississauga and The GTA
We provide fourplex construction services across Mississauga and the GTA, including
Caledon
Richmond Hill
Markham
King
Every project is reviewed against that municipality's own zoning, building, and approval requirements, since these can differ from one city to the next. For a fourplex conversion in Mississauga, we also assess the existing home and lot before design begins.
A Licensed, Insured Builder With Decades of Experience
With more than three decades of experience, GrandBuild Homes brings proven residential construction expertise to every project.
30+ Years in Residential Construction
100+ Homes Completed
HCRA Licensed
Fully Insured
Tarion Registered, Where Applicable
Fourplex Builder FAQs
Can I convert my existing house into a fourplex?
Possibly. The property needs to be assessed for zoning, building requirements, layout, structure, servicing, access, and other project conditions before feasibility can be confirmed.
Do I need planning approval for a fourplex?
The required approval depends on the property, zoning, and proposed development. A fourplex should not automatically be assumed to have the same approval path as a two- or three-unit property.
How much does it cost to build a fourplex?
The cost depends on the size, property conditions, construction method, structural work, servicing, finishes, and approval requirements. A project-specific scope is needed for meaningful pricing.
Can I find a fourplex builder near me?
GrandBuild works with homeowners and investors looking for a fourplex builder near me in Mississauga and throughout the GTA.
Do you handle fourplex conversions in Mississauga?
Yes. GrandBuild can assess an existing property for a fourplex conversion and determine whether adapting the existing structure or building new is the more practical option.
Can I find a fourplex conversion contractor near me?
GrandBuild provides fourplex conversion contractor near me services for suitable existing properties.
Can I convert a house to a fourplex near me?
A convert house to fourplex near me project should begin with a property assessment. Existing homes can differ significantly in layout, structure, servicing, and available space.
Start Planning Your Fourplex With a Clear Project Assessment
Looking for a fourplex builder near you in Mississauga or the GTA? GrandBuild Homes will review your property and outline the next steps.