Adaptation Standards and Guides for Northern Infrastructure and Buildings in Permafrost

Between 2016 and 2021, the Canadian Standards Association (CSA) Group developed and published a series of four new standards and guides on adaptation considerations for northern infrastructure and buildings in permafrost: 1) Technical Guide: Infrastructure in permafrost: A guideline for climate change adaptation (CSA PLUS 4011:19); 2) Technical Guide: Design and construction considerations for foundations in permafrost regions (CSA PLUS 4011.1:19); 3) Thermosyphon foundations for buildings in permafrost regions (CSA S500:21); and 4) Moderating the effects of permafrost degradation on existing building foundations (CSA S501:21).

Funding for the development of the Standard came from the Standards Council of Canada (SCC), as part of the Northern Infrastructure Standardization Initiative (NISI) with input from the Northern Advisory Committee (NAC).

The intent of these documents is to provide stakeholders with information on the potential impacts of climate change on infrastructure in Canada’s permafrost regions. It is recognized that climate change might impact permafrost terrain more dramatically than terrain in temperate regions. Those involved in the development, design, procurement, construction, and operations of infrastructure in permafrost terrain would benefit from current knowledge on the potential impacts of a changing climate on those activities.

This case study highlights the CSA S501:21 standard. This Standard has been developed through the collaboration of representatives from territorial governments, the federal government, universities, the private sector, and northern community government organizations.

This Standard was prepared by the Working Group on Permafrost Degradation, under the jurisdiction of the Technical Committee on Northern Built Infrastructure and the Strategic Steering Committee on Construction and Civil Infrastructure and has formally been approved by the Technical Committee. This Standard has been developed in compliance with Standards Council of Canada requirements for National Standards of Canada. It has been published as a National Standard of Canada by CSA Group.

Understanding and Assessing Impacts

Warming and/or thawing of permafrost due to climate change have been recorded throughout the North. The most comprehensive Canadian data on ground temperatures in permafrost are available from the Mackenzie River valley and the western Arctic coastlands. Increases of about 3 °C in the uppermost 10 m of the ground have occurred since 1970 near the western Arctic coast, and absolute change has been measured to depths of more than 50 m. In places, ground warming has further increased due to other consequences of climate change, such as the growth of vegetation and a deeper snow cover.

While permafrost degradation can be caused by many factors, amplified climate warming in the Arctic is driving significant threats to northern communities. When degradation occurs, buildings or structures constructed on permafrost can suffer distress or damage.

Identifying Actions

This Standard is organized according to the progression of steps that should be undertaken in order to moderate the effects of permafrost degradation on existing buildings or structures:

  1. pre-emptive and proactive measures to maintain permafrost beneath and adjacent to existing buildings or structures, including monitoring to verify their effectiveness;
  2. assessment of structures impacted by changing permafrost conditions. This includes the following steps:
    1. distinguishing the symptoms of building or structure distress related to permafrost degradation from those related to seasonal frost movements;
    2. investigating the site and structure conditions;
    3. establishing a directed monitoring program; and
    4. producing a final evaluation report that outlines alternative mitigative measures for the structure, recommendations for implementation of the appropriate mitigative measures; and the development of an implementation plan; and
  3. mitigating permafrost degradation and its effects on existing buildings and structures, as appropriate, including monitoring to verify performance.

The strategies available to moderate the effects of permafrost degradation on existing buildings or structures depend on site-specific conditions. The use of this Standard, therefore, requires a flexible approach.

Implementation

This Standard covers the following strategies to maintain permafrost or mitigate permafrost degradation related to existing buildings or structures:

Site techniques that consist of:

  • site grading and drainage;
  • snow management; and
  • shading or albedo change.

Foundation techniques that consist of:

  • ventilation;
  • ground insulation;
  • foundation adjustment and levelling; and
  • mechanized refrigeration and thermosyphons.

Intended Users

This Standard is intended to be used by the following:

  1. the owners and operators of buildings or structures that can be affected by the degradation of permafrost;
  2. the owners and operators of other community infrastructure (e.g., drainage systems) for which the maintenance of permafrost or remediation of permafrost degradation is important;
  3. building contractors who implement engineering-based interventions;
  4. design professionals and reviewers (consulting engineers, architects, and territorial or regional technical services staff) who design, assess and approve, and oversee the implementation of engineering-based interventions;
  5. educators, for the purposes of knowledge transfer; and
  6. regulators, such as building inspectors.

Outcomes and Monitoring Progress

The Standard provides guidance on monitoring and evaluating the long-term foundation performance under a changing climate.

Data from the directed monitoring program should be used as a baseline for comparison with performance monitoring data in order to assess the extent to which the implemented mitigations have been successful.

Performance monitoring will generally follow the methodology set out in the foundation maintenance plan, but the plan should be updated to include additional site-specific considerations that might have been introduced through mitigation activities for the foundation. This may include:

  1. routine visual inspections;
  2. recording and assessing crack monitoring points;
  3. conducting floor elevation and foundation element surveys;
  4. thermal monitoring of the subgrade, open air gaps, and floors;
  5. leak checks on water supply and sewage disposal systems;
  6. surface and groundwater monitoring; and
  7. operational monitoring of thermosyphons or other cooling techniques, if present.

Performance monitoring data should be evaluated by a qualified professional on a routine basis.

Resources

Link to the Full Case Study

Additional Resources: