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Key Findings
A total of 86 heritage properties, including built heritage resources and cultural heritage landscapes were identified within the Study Area. Identified heritage properties include:
- Six properties designated under Part IV of the Ontario Heritage Act:
- 10 Colborne Street
- 7780 Yonge Street, Robert West House (subject to Ontario Heritage Trust easement)
- 7788 Yonge Street, George Munroe House
- 42 Old Yonge Street, William Walton Armstrong House
- 8038 Yonge Street, Soules Inn
- 23 Hillsview Drive, David Dunlap Observatory Lands
- Two Heritage Conservation Districts (HCDs) designated under Part V of the Ontario Heritage Act :
- Thornhill Vaughan HCD (39 properties within the Study Area)
- Thornhill Markham HCD (15 properties within the Study Area)
- Three listed heritage properties:
- 5926 Yonge Street, City of Toronto Heritage Register
- 5 Patricia Avenue, City of Toronto Heritage Register
- 7951 Yonge Street, Edwardian House, City of Markham Heritage Register
- One Previously Identified Heritage Property
- 5925 Yonge Street
Figure 1: Boundary of the Thornhill Vaughan HCD
Potential Effects & Mitigation Measures
Potential Effects:
Construction Phase
- No impacts are anticipated to 29 built heritage resources/cultural heritage landscapes. Continued avoidance of these properties is recommended.
- Potential indirect impacts: Vibration damage related to the construction of the Project in the vicinity of a built heritage resource or cultural heritage landscape may occur at 43 properties.
- Potential direct impacts: Above-grade Project components are planned within, or adjacent to, 14 built heritage resources/cultural heritage landscapes. Vibration damage may also occur at these properties.
Operational Phase
- No impacts to identified BHRs/CHLs are anticipated as a result of project operations.
Figure 2: 15 Patricia Ave.; Listed on City of Toronto Heritage Register
Figure 3: 7951 Yonge Street; Edwardian House
Mitigation Measures:
Construction Phase
Where impacts are anticipated due to potential vibration impacts:
- In all cases, avoidance of the built heritage resources or cultural heritage landscapes is the preferred mitigation measure; only where avoidance was determined to not be feasible were mitigation measures prepared.
- Document (review and establish) the structural condition of the affected buildings to determine if they are vulnerable to vibration impacts from construction activities.
- Establish vibration limits based on structural conditions, founding soil conditions and type of construction vibration to ensure no damage to heritage structures.
- Implement vibration mitigation measures on the construction site and/or at the building.
- Monitor vibration during construction, with notification by audible and/or visual alarms when limits are approached or exceeded.
Where a direct impact such as demolition or alteration to a heritage property may occur:
- Complete technical studies, which may include Cultural Heritage Evaluation Reports and/or Heritage Impact Assessments for known or potential BHRs/CHLs where potential direct impacts such as demolition or alteration of heritage structures/landscapes may occur, as required. These studies will determine cultural heritage value or interest and provide a detailed impact assessment, conservation guidance, and property-specific solutions to mitigate Project impacts. Properties requiring such studies will be confirmed as project design progresses and property-specific impacts are identified.
- Consult with the MHSTCI, OHT, municipalities and other stakeholders as required.
Mitigation Measures:
Operational Phase:
No impacts to BHRs/CHLs are anticipated during Project operations, therefore no mitigation is required.
Figure 4: Inventory of Built Heritage Resources and Cultural Heritage Landscapes