Ingenious Insulation Under Isolated Conditions

The Old Crow Health Center

Located in Northern Yukon, the village of Old Crow was faced with a clear but difficult situation in 2018.  A government analysis of all health facilities in the Yukon determined that the aging health centre in this small Arctic community was clearly in need of rehabilitation. As no roads connect Old Crow to the rest of the world, only airways, this task promised to be particularly demanding. As is often the case in the North, this project presented unique challenges requiring creative and ingenious solutions.

Project Stakeholders

• Client: Government of the Yukon

• Architects: DGBK Architects and Northern Front Studio Inc. 

• General Contractor: Ketza Construction Ltd.

• Owner’s advisor: Stantec

• Building Envelope Consulting Engineer: RDH Building Science

• Mechanical and Electrical Engineer: Integral Group

Redefining Health Care in Old Crow

The original Old Crow Health Centre was built in the early 1970s, and despite an expansion in 1986, the building was aging and could no longer meet the growing needs of the population. In addition to a new health and wellness centre, an adjacent ten-unit housing complex was also to be designed to address the ongoing housing crisis.

The Government of the Yukon was working closely with the Vuntut Gwitchin First Nation Government to ensure the design of a new centre that would meet the needs of the community. The building would therefore be designed according to a collaborative care model to offer a combination of social and health services under one roof. The premises would also be reserved for regional therapies and dental care – a novel approach for the Yukon. The initial plan was meant to evolve and adapt in order to meet the needs of neighbouring communities.

Building in the Depths of Winter: The Road to Insulation

The project was designed and led by the DGBK architectural team, supported by the local design expertise of Northern Front Studio. The build was entrusted to the Whitehorse-based contracting company Ketza Construction Ltd., which was awarded the contract worth over 44 million dollars. The team of RDH Building Science also contributed to the project with their northern building envelope expertise. Work began in 2021 and completion is expected by March 2024.

This type of project presented unique geographic challenges that required careful consideration during design. Old Crow is the northernmost community in the Yukon, close to the Arctic Ocean. Construction therefore had to consider permafrost, a distinctive soil in the region. In recent years, climate change causes this layer of soil to melt, which weakens its bearing capacity and can have disastrous consequences on the solidity of infrastructure. To adapt to this condition, many buildings are designed on piles.

While this type of foundation reduces the risk associated with thawing permafrost, it also creates additional exposed surface area underneath the building, which requires special attention when installing and detailing insulation and air barriers in order to optimize energy performance. Given the high climatic requirements of the region due to extremely cold winters, the thermal efficiency of buildings in this region is a priority concern.

Another major challenge of this project was the geographic accessibility of the community. Normally, it is only possible to get to Old Crow by plane, which presented a significant obstacle to the delivery of materials in terms of cost and time. To facilitate the progress of the work, the Government of the Yukon and the Government of the Vuntut Gwitchin First Nation had planned the construction of a winter road of over 260 kilometres connecting Eagle Plains to the village of Old Crow. Although this was not the first time that such a road had been built, its construction remained quite exceptional since it had not been done since 2014.

This crossing made up of snow and ice was, however, far from easy to navigate. To successfully move the truck convoys on this temporary road over a nearly 10-hour period, it was not only essential to work efficiently but also make the most of the space available.

SOPREMA Protected Assembly: An Innovative Insulation Strategy

With two buildings and a total building envelope of over 50,000 square feet of roofs, walls and suspended floors to be waterproofed, air-sealed, and insulated, it was necessary to maximize the performance of the assemblies while minimizing the quantity of materials to be shipped to Old Crow.

Initially, the effective R-value target for the exterior wall assembly was set at R-45.4 (RSI 8.0). At that time, two insulation options were considered by the designers for the steel-framed wall:

Option No. 1

Entirely exterior insulated wall made of 12 inches of mineral wool used in combination with stainless steel screws to fasten the exterior cladding;

Option No. 2

Split insulated wall consisting of 8 inches of mineral wool on the exterior and 6 inches of mineral wool batt in stud wall cavities, used in combination with fibreglass or stainless thermal clips to attach the exterior cladding.

‘‘The effective R-value target for the exterior wall assembly was 8.0. Several different wall assemblies were suggested in the indicative design. However, each assembly presented issues in terms of constructability, thermal bridging, manufacturer limitations in tested insulation thickness, or they were just shy of the required RSI.’’

- Eric Brohman, Ketza Construction Ltd

It was at this time that SOPREMA experts recommended an innovative Protected Assembly to Ketza. This assembly combines two insulation materials, SOPRA-ISO V (polyisocyanurate insulation) and mineral wool, with cladding attached to ACS THERMAL CLIPS system. The insulation strategy consists of encapsulating SOPRA-ISO V with mineral wool, making it possible to achieve a much higher R-value with less insulation, while benefiting from the non-combustible nature of mineral wool. The advantages of the two insulation materials combine to offer maximum performance and R-value.

The option proposed by SOPREMA to effectively meet the needs of the project was an 8-inch exterior insulated wall assembly including 6 inches of SOPRA-ISO V ALU and 2 inches of mineral wool. By selecting the SOPREMA Protected Assembly, the required insulation thickness could be reduced by 4 inches compared to option No. 1, or 6 inches compared to option No. 2. This reduction in materials constituted an undeniable advantage, not only in facing the logistical challenges of delivery to the site, but also positively impacting the project cost. 

“A lot of materials had to be transported, so it made sense to use less exterior insulation if we could achieve the same effective R-value. By using polyiso in the fully exterior insulated wall, we could reduce the amount of total insulation volume and weight to be shipped.”

– Graham Finch, RDH Building Science Inc

The protected assembly not only allowed cost and material savings, but also provided a higher effective R-value than initially required (47.5 [RSI 8.36] compared to 45.4 [RSI 8.0]). The ability to create a more efficient wall assembly with less was becoming a reality.  

Additionally, the use of stainless steel ACS THERMAL CLIPS as a cladding attachment system helped to effectively reduce thermal bridging in the wall assembly, ensuring maximum thermal efficiency. In Old Crow’s subarctic climate, the thermal performance of a building makes all the difference to the comfort of occupants, the durability of the enclosure, and to the amount of energy needed to power it. The SOPREMA Protected Assembly therefore quickly emerged as the obvious solution to the energy challenges of this project.

‘‘The SOPREMA Protected Assembly was the solution that worked, meeting the required RSI and addressing thermal bridging issues, thus satisfying project requirements. It was also a straightforward system where we could train installers and maintain a high level of quality control.’’

- Eric Brohman, Ketza Construction Ltd

Airtightness, a Core Issue

Airtightness is critical to a building’s performance, especially in extreme weather conditions such as those in the Yukon. This is why RDH was mandated on behalf of the team to help design and commission the airtightness components of the two new Old Crow Health Centre buildings in order to ensure maximum performance. The two buildings had very strict airtightness objectives as part of the project requirements with design energy model targets requiring an effective air infiltration rate of 0.1 to 0.16 L/s/m² at 5 Pa for the housing and healthcare buildings. With the design of a continuous air-barrier system around both buildings and all of the efforts made during construction to seal them up, the team managed to achieve infiltration rates of 0.055 and 0.065 L/s/m² at 5 Pa (converted from test results at 75 Pa), which is well below the usual energy modelling assumption of 0.25 L/s/m² at 5 Pa. In other metrics, the results were about twice as high as a passive house building (0.6 ACH at 50 Pa). Achieving such a good result is due not only to the quality of SOPREMA membranes placed continuously over the walls, floors and roof, but also a result of the attention to detail of the Ketza team and subtrades during installation.

“Ensuring airtightness at this level requires a construction team that does professional work and pays extra attention to all of the little details like extra bits of tape or sealant at membrane transitions and penetrations, which Ketza did here superbly.”

– Graham Finch, RDH Building Science Inc

Technical Support, Despite the Distance

As the protected assembly was a new insulation strategy, few projects had been carried out with this type of system. The Ketza team had the challenge of familiarizing themselves with the installation of this new assembly, all in the midst of a pandemic which limited travel. These constraints made it difficult for our experts to be physically present in Old Crow to support the team on site. Despite everything, our team was determined to assist the installers and ensure the success of the project. The Ketza and SOPREMA teams were therefore in frequent communication through telephone consultations, online meetings and even live installation videoconferences.

‘‘From the very beginning of the project at tender time, we were evaluating the constructability of the suggested wall systems and how this new assembly would satisfy the requirements of the project straight through to installation demonstrations and completion.’’

- Eric Brohman, Ketza Construction Ltd

For this institutional project, the technical details inherent in the products used in the proposed assemblies were essential. Due to the unique geographic conditions, it was necessary to provide evidence of the performance of the materials at low temperatures that would specifically meet the requirements of the Yukon.

“The members of the SOPREMA team were invaluable in providing us with the necessary technical information, specifically to address effective cold temperature performance of the insulation combination used here. Their contributions played a crucial role in this project and acceptance of the owner’s project requirements.”

– Graham Finch, RDH Building Science Inc

Thanks to this close collaboration, the installation of the Protected Assembly was carried out smoothly and on time. The official opening of the new Old Crow Health Centre, as well as the new housing units, is planned for spring 2024.

"SOPREMA’s products have been used extensively in the Yukon for many years. Their roofing system and Protected Assembly for walls are expected to contribute to high performance levels for the building envelope over the long term for this project. SOPREMA’s technical staff provided specific and helpful advice and quality assurance assistance for their products during the cold weather conditions encountered during application."

– Peter Blum, Senior Building Program Manager, Yukon Government

Building Beyond Limits

This case study of the Old Crow project demonstrates not only the exceptional challenges the team faced, but also how innovation and collaboration were the keys to success. Building a health centre and a new housing unit in a remote Yukon village accessible only by plane required careful planning and creative solutions. The decision to use the SOPREMA Protected Assembly proved to be a wise one, as it addressed the logistical challenges of delivering materials while optimizing the energy efficiency of the building in a demanding subarctic environment.

‘‘We were pleased to find a solution that wouldn’t result in a 12-inch-thick exterior assembly, which improved detailing the openings and associated structural requirements while maintaining required fire protection.’’

- Eric Brohman, Ketza Construction Ltd

Beyond technical design, the close collaboration between the Government of the Yukon, the Vuntut Gwitchin First Nation, the architects, consultants, contractors, and SOPREMA was a determining factor in the success of the project. Not only did this result in the construction of a new health and wellness centre, but it also introduced a higher level of health and wellness care within the Old Crow community. SOPREMA is proud to have participated in meeting the challenges in this project!