What is a Heritage Impact Assessment?
A Heritage Impact Assessment (HIA) evaluates the impact of a proposed development, building alteration or site alteration on a built heritage resource(s) or a cultural heritage landscape(s). It recommends mitigation measures or alternative development approaches to conserve the heritage attributes of that resource/landscape. HIAs are an important planning tool to ensure that the heritage values, attributes, and integrity of cultural heritage resources are considered in the land development process. HIA's are generally provided for large development projects and are completed by a member of the Canadian Association of Heritage Professionals (CAHP).
The HIA shall be based on accepted conservation principles and guidelines, including the following:
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- The Parks Canada Standards and Guidelines for the Conservation of Historic Places in Canada;
- Eight Guiding Principles in the Conservation of Historic Properties;
- Ontario Heritage Tool Kit;
- Well Preserved: the Ontario Heritage Foundation’s Manual of Principles and Practice for Architectural Conservation.
When is a HIA Required
The Planning Department will ask for a HIA for large projects or when the potential impacts of a proposal may be severe. A Heritage Impact Assessment may be required for the following types of properties:
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- Property designated under Part IV the Ontario Heritage Act (individual designation)
- Property designated under Part V of the Ontario Heritage Act (located within a Heritage Conservation District)
- Property that is adjacent (contiguous) to individually designated properties or a Heritage Conservation District
- Property that is listed on the Municipal Heritage Register as a "Property of Interest" (POI).
The following types of planning applications may require a HIA for the above property types, including (but are not limited to):
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- Heritage Alteration Permit Application
- Site Plan Control
- Zoning By-law Amendment
- Official Plan Amendment
- Draft Plan (Subdivision and Condominium)
- Consent or Minor Variance application under s. 45 of the Planning Act
- Site Alteration
- Building Permit
At staff’s discretion, an HIA may be scoped to reflect anticipated impacts on a heritage resource, or waived if there is sufficient information to suggest there will be no impacts on a heritage resource (e.g. erection of a temporary structure).
Contents of a HIA
Part I - Identify the Cultural Heritage Resource
Site Documentation and Analysis/Site Information.
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- Document the context in which the site is located (may include Aerial Photo, Location Map, and context with the area), including adjacent properties and land uses.
- Describe the site and all structures on the property and its heritage status under the Ontario Heritage Act, and identification of any heritage easements or restrictions.
- Document the existing condition or concerns surrounding the property, including quality photo documentation.
Research on Design/Physical and Historical/Associative and Contextual Values.
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- Describe all heritage resources and values within the subject property (include exterior and interior, landscaping etc.)
- Include a chronological history of the property from land and development history, building history (document any additions or alterations, etc. to property), with confirmation to construction dates .
- Include ownership and user history.
- Research material should include relevant historical maps, drawings, photographs, land records, assessment rolls, Town directories, news articles etc.
- Provide summary on significance and heritage attributes for each structure existing on the property.
Part II - Proposed Site Changes/Development and Impact to the Cultural Heritage Resource
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- Describe site changes to the heritage resource.
- Describe positive and adverse impacts of site changes to the heritage resource and surrounding lands. Refer to the adverse impacts identified in the Ontario Heritage Toolkit, which may include, but are not limited to:
- Removal/destruction of heritage features and loss to cultural heritage values;
- Changes to the historic fabric and impact on the appearance;
- Shadowing impact that may alter the appearance of the heritage attribute;
- Isolation of heritage attribute from its surrounding environment, context or a significant relationship;
- Obstruction of significant views or vistas within, from, or of built and natural features;
- Change in use and impact on heritage resource;
- Land disturbance and impact on soils, drainage patterns affecting built heritage or archaeological resources;
- Provide drawings;
- Provide visual depiction of subject proposal and streetscapes with neighbouring properties (eg. composite photograph of the subject property streetscape with and without the proposed development)
- Assess and describe the structural concern of the impact of proposed changes to the heritage resource.
Part III - Options for Mitigation and Alternatives
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- Consider and describe alternative conservation/mitigation and development options that reduce and avoid negative impacts to the heritage resource.
- Assess and clarify the benefits and negatives of each option proposed and the conservation principles used.
Part IV - Recommended Conservation Strategy
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- Rationale and Justification for the chosen option, specifying how the option ensures protection and enhancement of the heritage resource
- Conservation Scope of Work
- Implementation and Monitoring Plan when development is undertaken
- Provide References/Samples/Precedents to Conservation work
Part V - Other Requirements
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- Provide bibliographical sourcing of all research material.
- HIA is to be prepared by a qualified cultural heritage conservation professional who is a member of the Canadian Association of Heritage Professionals.
- Town Staff will determine the completeness or acceptance of the HIA.
- For review of the HIA, Town staff may be required to conduct site visits on the property.
- The Town of Amherstburg reserves the ability to require an alternative option for mitigation for consideration.
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