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Legal Basement Apartments
Design build basement apartments across Mississauga, Oakville and Burlington, engineered, permitted, inspected, and finished to a standard that lasts.
Legal Basement Apartments Starting at $75,000
Legal basement apartment construction starts at $75,000 for qualifying projects with an existing compliant separate entrance. This is a qualifying project starting price, not a universal per square foot rate or a fixed quotation. The starting construction package includes the kitchen, bathroom, required fire and sound separation, applicable electrical, plumbing and mechanical construction, required permit drawings and application coordination, required construction inspections, and standard agreed flooring, drywall, painting and finishing work, as defined in the written package scope.
An existing compliant entrance can satisfy the starting package assumption. Construction of a new exterior basement entrance is separately priced when required and is not automatically included in the starting price.
Prices are preliminary budgets in CAD, before applicable HST, not fixed quotations or guaranteed final costs. Final pricing is confirmed through a written proposal following a detailed assessment.
A separate, self contained dwelling with its own kitchen, bathroom and exit, fire and sound separated from the main home, permitted and inspected. Built to be rented or lived in by extended family.
You are on the right pageMore living space for your own household: a family room, bedroom, gym, office or guest suite with a bathroom. For your own household, rather than a separate rental dwelling.
See Basement FinishingNot sure which one fits your plans? We help you decide during your free consultation.
New to legal basement renovations? Read our complete homeowner's guide.
A legal basement apartment, also called a secondary suite or additional residential unit, is a self contained dwelling within an existing home, built to the 2024 Ontario Building Code and your municipality's zoning bylaws. Once permitted and inspected, it can be legally rented or occupied by extended family.
ScaleBig coordinates construction around the approved design and agreed scope. A legal suite requires appropriate kitchen and bathroom facilities, exits, fire and sound separation, and applicable mechanical and safety improvements. An existing compliant entrance may be used where appropriate; constructing a new exterior entrance is priced separately unless expressly included in the written proposal.
A legal suite is a different project from a finished basement. A legal suite involves additional construction requirements and municipal inspections. It creates a separate dwelling, with approvals that you can discuss with your insurer and a real estate professional. If you plan to rent the space, it needs to be a legal suite.
Legal Basement Apartments Experiences
Every package receives the same professional construction standards, applicable code compliance, proper workmanship and project coordination. The difference is the outcome, design, layout, finish selections and scope complexity, not safety or construction quality.
Representative comparison: Approximately 850 sq. ft., with a suitable existing separate entrance, feasible ceiling height and no major structural modifications.
Premium
A personalized self contained apartment with elevated finishes, enhanced functionality and thoughtful design details.
Representative scope
Expanded living layout, upgraded kitchen and bathroom, enhanced lighting, additional storage and refined finishes.
Investment tailored to your project
Book a Free ConsultationSignature
RecommendedA comfortable, functional apartment designed for independent living with balanced finishes and practical features.
Representative scope
Defined bedroom, living area, complete kitchen, three piece bathroom, coordinated lighting and durable finishes.
Investment tailored to your project
Book a Free ConsultationEssential
A complete, straightforward apartment conversion focused on functionality, durability and efficient use of space.
Representative scope
Compact self contained layout, functional kitchen, three piece bathroom, appropriate living and sleeping areas and standard finishes.
Investment tailored to your project
Book a Free ConsultationThese are representative renovation experiences, not fixed price contracts or interchangeable component bundles. Existing pricing references elsewhere on this page relate to their stated qualifying scopes, not quotations for the scenarios above.
Every experience follows the same applicable legal, building and life safety requirements, professional workmanship and project coordination.
Property eligibility, zoning, permits, entrance suitability, ceiling height, egress and construction requirements must be verified. Municipal approvals cannot be guaranteed.
A new separate entrance is not automatically included in Premium or excluded from Essential. Entrance requirements and any additional construction depend on the property and the agreed scope.
Our packages illustrate different renovation experiences and representative project scopes. Every property is unique, so your final quotation is tailored to your layout, existing conditions, selected finishes and construction requirements.
We'll help you choose the right direction and develop a complete project scope around your goals.
We believe homeowners deserve clarity about when their renovation will be completed.
Before construction begins, we'll provide an agreed project schedule with a target completion date. We'll keep you informed of progress, communicate clearly and manage the work toward the agreed timeline.
Initial consultations and estimates are free. Separately contracted design, engineering, permit applications or advanced assessments are not automatically free and may require an additional agreement.
Before starting a legal basement renovation, it's important to understand the planning process, permits, inspections, costs, and decisions involved. Our comprehensive homeowner guide explains the key steps so you can plan your project with greater confidence.
Read the Free Homeowner GuideMost basement apartments fail in one of three places: ceiling height, separate entrance, or zoning. We address those before design begins. A site visit and feasibility review establishes what's possible on your specific property before any drawings or budget commitments are made.
Design is led by our in house designer. Layouts, finish selections, and photorealistic 3D renderings are developed before construction starts. The same vetted, accountable trades handle every phase of the build, with consistent coordination throughout.
ScaleBig can coordinate the permit and application process for its renovation projects, including coordinating qualified designers and engineers, organizing required drawings and supporting documentation, preparing and coordinating application submissions, communicating with municipal reviewers, coordinating required construction inspections, and tracking applicable approval and closeout documentation. For qualifying advertised construction packages, required standard coordination and identified drawings and inspections are included as described in the written scope. ScaleBig does not personally provide licensed engineering services, and municipal approvals and timelines cannot be guaranteed.
Starting pricing applies to qualifying projects with a defined standard construction scope and suitable existing conditions. Depending on the approved design and property requirements, work may involve kitchen and bathroom construction, plumbing, electrical, HVAC, fire and sound separation, insulation, finishes, and other compliance related improvements. Specific materials, allowances, design details and technical requirements are defined in the written proposal.
Ceiling height verification, separate entrance review, zoning confirmation, and structural assessment before design begins.
Full layout, finish selection, fixture specification, and photorealistic renderings produced by our in house designer before construction starts.
Appropriately qualified professionals prepare drawings as required. Professional services are included only when expressly identified in the written proposal.
ScaleBig can coordinate the permit and application process for its renovation projects, including coordinating qualified designers and engineers, organizing required drawings and supporting documentation, preparing and coordinating application submissions, communicating with municipal reviewers, coordinating required construction inspections, and tracking applicable approval and closeout documentation. For qualifying advertised construction packages, required standard coordination and identified drawings and inspections are included as described in the written scope. ScaleBig does not personally provide licensed engineering services, and municipal approvals and timelines cannot be guaranteed.
Beam installations, load bearing modifications, and below grade entrance construction can be arranged where required, subject to engineered drawings and the agreed scope. New exterior entrance construction is separately priced unless expressly included in the written proposal.
Framing, plumbing, electrical, HVAC, and ventilation rough ins to current code, including dedicated panel and separate water lines where applicable.
Code compliant fire rated assemblies between units, with acoustic upgrades to help reduce sound transmission.
Window sizing, cutting, and installation to meet egress requirements for any bedroom location.
Wall and ceiling insulation to current OBC requirements, plus waterproofing at affected foundation areas.
Drywall installation, taping, mudding, sanding, and primer.
Luxury vinyl plank, tile, baseboards, trim, and door installation to the finish standard selected during design.
Cabinetry, countertops, plumbing fixtures, custom tile work in wet areas, lighting, and appliance integration.
Fire rated pot lights, dedicated circuits, separate panel for the suite, and any required upgrades to the main panel.
Interconnected smoke and carbon monoxide alarms across the full home, sized and wired to current code.
Coordination of required construction inspections under the agreed scope. Municipal approval is determined by the municipality, not guaranteed by ScaleBig.
One project manager from start to handover, and one number to call.
Major structural alterations, underpinning, unusual excavation and extraordinary property specific requirements are separately scoped. Specialized engineering, unusual municipal requirements, additional professional services and third party fees are identified in the written proposal, whether included in the package or separately priced.
You approve the finishes. We coordinate ordering and delivery, with material availability and lead times considered before construction starts.
Our in house designer prepares a selection sheet with flooring, tile, cabinetry, countertops, fixtures, lighting and appliances, priced within the allowances in your proposal. You sign off on each item.
Items with the longest lead time are ordered first, as soon as your selections are approved.
Selections are locked by a date in your schedule. Late changes move the schedule and are priced in writing.
Anything above an allowance is quoted in writing before we order it. You never see a surprise on the final invoice.
After you sign, you approve your final selections and pay for finish materials and appliances, so everything is ordered before construction starts.
Legal basement apartment construction starts at $75,000 for qualifying projects with an existing compliant separate entrance, with typical project budgets of $75,000 to $150,000 or more. Actual project pricing depends on size, existing conditions, ceiling heights, code requirements, structural changes, mechanical upgrades, finishes and municipal requirements. Prices are preliminary budgets in CAD, before applicable HST, not fixed quotations or guaranteed final costs. Final pricing is confirmed through a written proposal following a detailed assessment. The factors below explain how property conditions and the agreed scope affect the budget.
Whether the basement is unfinished, partially finished, or has prior unpermitted work that needs to be opened up and verified. Older homes with low ceilings, small windows, or limited foundation drainage typically require more work to bring to code.
A new exterior basement entrance starts at $18,000, with a typical planning range of $18,000 to $29,000 or more. Suitability and final pricing depend on excavation and site access, concrete work, exterior stairs and landing, structural modifications, drainage and waterproofing, required engineering and municipal approvals, and existing foundation and site conditions. Not every property is suitable. An existing compliant entrance can satisfy the starting package assumption. Construction of a new exterior basement entrance is separately priced when required and is not automatically included in the starting price.
Removing a load bearing wall to open the floor plan, or underpinning to gain ceiling height, requires engineered drawings and substantially different construction. Both are routine for us; both meaningfully change the budget.
If bedroom windows are undersized, they need to be cut to egress specifications. That work involves the foundation wall and typically requires engineering review.
Separate electrical panel, dedicated HVAC strategy, separate water lines, and code compliant ventilation all add real cost. Older homes sometimes require main panel upgrades to support the additional load.
The same suite can be built to a tenant suitable standard or to a near main floor standard. Cabinetry, tile, fixtures, flooring, and trim choices have significant cumulative impact.
Construction inspection coordination follows the agreed scope. Permit drawings, formal applications, municipal correspondence and related professional services are arranged according to the written proposal; optional application coordination may be quoted separately.
A specific budget for your project is developed during the free consultation and site visit, after we've reviewed the conditions and discussed the scope you're looking for.
Every legal basement project at ScaleBig follows the same sequence. The timeline below reflects an average project. Specific milestones vary by scope and municipal review times.
We discuss your project, review the preliminary scope and budget, and arrange an initial site visit where appropriate, to measure finished heights, review existing conditions, and confirm zoning. We give you an honest read on whether the project is feasible and what scope it will likely require. The initial consultation and estimate are free.
Our in house designer develops layout options, finish selections, and photorealistic 3D renderings. You see the finished space in detail before construction begins, and material decisions are made with full visibility.
Required drawings are prepared by appropriately qualified professionals. Formal applications, municipal review correspondence and any resubmissions are arranged according to the agreed scope. Optional application coordination may be quoted separately.
A fixed price proposal with the scope set out by category, allowances, milestones and a dated schedule, plus the payment schedule and exclusions. Once signed, the project is scheduled.
You approve the final selection sheet and pay for finish materials. We order everything so it is on site before construction starts.
The same trades handle every phase. Inspections are coordinated at each stage. You're informed of progress and consulted on decisions in real time.
Municipal sign off, ESA certification, a complete walkthrough, and handover of all documentation: permits, warranties, manuals and inspection records.
Typical timelines: 4 to 8 weeks for design and permits, then 10 to 16 weeks of active construction depending on scope.
Some elements of a legal basement build are easy to cut corners on. We don't.
Any structural modification, such as load bearing wall removal, beam installation or a below grade entrance, is built from stamped drawings produced by a licensed Professional Engineer. No exceptions.
We use resilient channel, Roxul Safe and Sound acoustic insulation, and 5/8" drywall as our standard sound assembly. This goes beyond minimum code and is the difference between a suite people can comfortably live in long term and one that generates complaints.
Every fire rated assembly is built to the specified rating using the right materials, in the right sequence, with no substitutions. Self closing fire rated doors are sized and installed correctly, not retrofitted from standard hardware.
Required permits must be issued before the applicable construction begins. Formal application responsibilities and construction inspection coordination are established in the agreed scope. Municipal approvals and review timelines cannot be guaranteed.
The same plumbers, electricians, tilers, and finishers across projects. If work doesn't meet our standard, it gets corrected before the next phase begins.
Two tools to help you evaluate whether a legal basement apartment is right for your home.
A short, free preliminary check of selected factors that may affect a legal basement apartment, including ceiling height, entrance, egress and zoning. Takes about two minutes.
Take the QualifierExplore annual rental income, a simple payback estimate and a 10 year income projection using your rent and project cost assumptions. A starting point for planning, not a forecast of investment returns.
Open the CalculatorEvery legal basement project begins with a conversation about the property, to verify the conditions, confirm what's possible, and produce a realistic scope and budget. If you're considering a basement suite for income or family, this is the right next step.
Book a Free ConsultationOr call us at 647-289-2823
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Tell us a little about the basement and we will call to arrange the visit.
