How to Legally Build a Unit up to 1,500 sq. ft?
To build a residential unit up to 1,500 sq. ft., follow these steps:
- Zoning Check: Ensure that your property is eligible for a larger ADU. This will require local zoning approvals and additional permits for a larger construction.
- Project and Plan Preparation: Prepare a detailed project, including utility connection plans, fire safety measures, and architectural and engineering drawings.
- Individual Permit: In some municipalities, an increase in the allowable size of an ADU may be possible. This requires submitting a special request and obtaining approval from city authorities.
- Completion of Permitting Process: Once all necessary documents are submitted and the project is approved, construction can commence.
Comparison Table: Secondary Dwelling Unit (SDU), Accessory Dwelling Unit (ADU), and Garden Suite
| Feature | Secondary Dwelling Unit (SDU) | Accessory Dwelling Unit (ADU) | Garden Suite |
|---|---|---|---|
| Location | Within the main house (e.g., basement, attic) | Detached or attached to the main house; includes standalone structures (e.g., Garden Suite) | Typically detached, located in the backyard of the main house |
| Maximum Size | Limited to 807 sq ft or 75% of the primary dwelling's size | Typically limited to 807 sq ft, but larger sizes may be allowed with municipal approval | Maximum 60 sq m (646 sq ft) or 40% of the backyard area |
| Building Type | Incorporated into the primary structure | Separate structure or large addition | Detached structure |
| Separate Utility Connections | Not typically required | Usually required for detached ADUs | Required for separate structures |
| Application and Documentation | Standard application and permit process; simpler forms | More extensive application process, may require additional documentation | Standard application process; zoning and additional documentation required |
| Municipal Zoning Compliance | Typically complies with main house zoning | Requires adherence to additional zoning regulations for separate units | Must comply with additional zoning for backyard use |
| Approval Timelines | 4-6 weeks, varies by municipality | 6-10 weeks, depending on project size and location | 4-8 weeks, varies by location |
| Cost of Permits | Lower than ADU; exact cost varies by city | Higher than SDU; varies widely by municipality | Moderate cost; varies by municipality, generally similar to ADU |
| References | Ontario Guide | Hamilton Guide | Toronto Guide |
Conclusion:
The Garden Suite is the simplest and quickest option for an additional dwelling unit, as it requires minimal changes to the property structure, fewer permit restrictions, and a faster construction time. For larger spaces, like a 1,500 sq. ft. unit, coordination with municipal authorities is necessary, along with additional zoning and design requirements.
