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Interview with Lucie Andlauer of Subterra Renewables

Lucie Andlauer is CEO of Subterra Renewables, a Toronto-based company which takes geothermal energy beyond the installation step.

1. What does Subterra do?

Subterra invests in the renewable energy efforts of our clients and enables them to build socially conscious developments. We build, own, and operate geothermal energy systems to provide 24/7 clean, renewable energy and ultimately replace conventional systems. Subterra works with our clients to enable them to meet future sustainability and energy efficiency requirements. Our goal is to simplify going green. Our geothermal systems offset natural gas consumption by making the building reliant on electricity, with an overall more efficient system as a result of utilizing the ground over traditional mechanical equipment. Subterra coordinates closely with the consultant teams of buildings in order to customize a system in accordance with the trifecta (customer, client, and environment).

2. Can you explain a little more the range of services you provide? 

Subterra Renewables specialises in geothermal heating and cooling systems for multi-residential and commercial buildings. These systems exchange heat with the earth below the building to create a thermal storage battery that discharges when the building needs heat in the winter and recharges when the building needs to shed heat in the summer.

We offer an end to end design and installation service as well as an ‘Energy as a Service’ utility program where we invest in the renewable energy asset to remove the barrier of initial capital investment. The following is the complete list of services offered by Subterra:

System design (engineering)

Energy as-a service

Complete geothermal system installation owned by Subterra at no upfront cost to the developer in exchange for an ongoing monthly renewable energy fee.


Complete geothermal system financed and owned by the building owner; operations, maintenance, and ongoing reporting can be provided by Subterra.

System Acquisition

Acquisition of existing/operating geothermal assets and/or portfolios.

Geothermal Drilling

Complete drilling services for vertical borehole drilling for depths below 600’ – 900’ +

Shoring & Earth Retention

Variety of services related to the early stages of projects that can be arranged in succession with geothermal drilling.

Test Hole and Thermal Conductivity Testing

We can drill test holes and have thermal conductivity testing equipment to analyze test holes and project feedback prior to finalizing a design.

3. Does Subterra effectively act as a utility?

Yes – because we own, operate, and maintain the system. By doing so, we can charge an all-inclusive renewables energy fee.

4. With a new project, who do you deal with to consider using geothermal?

We get approached by the main proponents in the development community, namely architects, developers, and construction managers etc.

5. Is it practical to say that a system like yours could replace fossil fuels for heating most buildings?

Absolutely, geothermal can offset all-natural gas in buildings. In practicality, many engineers prefer to have a small component of the building connected to natural gas and domestic hot water. We are actively trying to make the switch to go green entirely.

Third & Hawkins Condo

Local residents band together to offer comfort and high efficiency to downsizers

By Mary Ellen Read

Located in downtown Whitehorse, this six-storey, predominantly wood-frame structure is the brainchild of three couples, none with previous construction or development experience. They joined forces with a common purpose: to develop a sustainable, community-oriented residential building that would also meet market expectations of comfort and luxury.

Enthusiastically supported by the local council, the development objective was to encourage downsizing owners to return to the city’s downtown core. Located in the well-established south-end of town, the building is only a few blocks from the dynamic urban amenities of Main Street, three parks with playgrounds are within 0.5 km, and both the Waterfront Trail and Millennium Trail (popular among urban hikers, dog-walkers, and joggers) are just steps away.

The majority of the units are 1,200 square feet with two bedrooms. The developers occupy three of the four penthouses, while the remaining units were sold at market value to finance construction. This innovative approach to development helped expand the inventory and diversify the options for those wanting to live downtown.

The building is a pinwheel shape in plan; rotated 15-degrees from the property lines to allow each unit to have multiple exposures for daylight and views to the mountains. 

With the primary target market being active seniors, the building is designed to facilitate aging in place. However, the generous hallways and wide wheelchair-friendly doorways create a sense of spaciousness that appeals to everyone.  Other accessibility features include zero-threshold showers; grab-bars strategically placed throughout; lever handles on doors and faucets; under counter and task lighting in kitchens; and high-contrast edges between walls and floors for residents with low vision.

The 15-degree rotation in plan creates inviting outdoor parkettes on two corners, planted with low-maintenance native shrubs. Large sections of permeable surfaces allow water to percolate into the ground, minimizing the impact of the spring freeze/thaw cycle and reducing stress on the local sewer system. 

Parking is at ground level since the down-ramp would require more space than the building’s compact footprint would allow. Concrete is also an expensive commodity to source in the North, and the additional cost of an underground parkade could not be justified.

Mary Ellen Read is a principal at Northern Front Studio.

The building is equipped with a high-efficiency central ERV system, specifically a RG 2000, by Winnipeg-based Tempeff. Acting as the building’s lungs, the ERV not only recovers heat, but also factors in humidity making it the best choice for occupant comfort in a cold, humid climate. The ERV makes use of Dual-Core technology allowing for continuous fresh air supply and frost-free operation in this climate.


The ReCover Initiative

By Emma Norton, Nick Rudnicki and Lorrie Rand

Nova Scotia has committed to aggressive reductions in greenhouse gas emissions, targeting a 53% reduction below 1990 levels by 2030, and net zero emissions by 2050. A recent report by Brendan Haley and Ralph Torrie states that existing buildings are responsible for 47% of Nova Scotia’s GHG emissions. Read more …

In 2030, more than 75% of the building stock in Nova Scotia will be composed of buildings in use today, and an estimated 60% of those buildings will still be in use in 2050. This means that existing buildings will have a large impact on meeting Nova Scotia’s emissions targets.

In light of these facts, the ReCover Initiative was established to develop a Deep Retrofit methodology for Nova Scotia that can be implemented at a large scale.

Our goal was to achieve enough energy savings to ensure that the building could be net-zero with the addition of renewables. As such our approach involved energy savings through superinsulation AND an airtightness target of 1 ACH (passive house retrofit target), fuel switching of the building mechanicals (from fuel oil to electric), and addition of high-efficiency new equipment, including dedicated ERVs in each unit and then solar PV.. Essentially the pathway is to conserve as much energy as possible, to electrify everything, and then to offset the small amount of energy needed with renewables.

Our team performed a pilot design, with the support of Quest Canada and the Nova Scotia Department of Energy and Mines, to demonstrate the potential reductions in energy consumption and GHG emissions that could be achieved by applying this methodology to the retrofit of a low-rise MURB (multi-unit residential building) pilot building in Halifax.

Conventional methods of performing deep energy retrofits are slow and expensive, because every project is custom, as every building is unique. The ReCover Initiative is based on a systematic, turnkey approach to affordable deep energy retrofits, developed in the Netherlands, called Energiesprong (“energy leap”).

The ReCover process involves wrapping the building in a new prefabricated skin and replacing the mechanical systems with smaller, more efficient components. This work is faster and less disruptive than a typical renovation, and it allows for occupants to remain in their homes throughout the work. Additionally, following a proven, systematic process reduces risk to the contractor and reduces costs to the owner.

Emma Norton is with QUEST Canada; Nick Rudnicki is CEO RSI Projects and a Passive House-trained builder; and Lorrie Rand is president of Habit Studio and a Certified Passive House Designer.


Sponsored content: Building the future of nuclear through responsible waste disposal

Plans have been laid for the construction of a highly engineered radioactive waste disposal facility in Chalk River, Ontario, Canada. The facility is being proposed as a permanent and modern technological solution to an environmental issue that goes back almost a century.

Today, Canadian Nuclear Laboratories (CNL) is seeking the support of the industry and its supply chain to move this project forward and advance the future of waste disposal in Canada.

Canada’s storied Chalk River Laboratories (pictured right) was established in 1944 on the Ottawa River, about 180 km (114 miles) from the City of Ottawa. An adjacent community, the Town of Deep River, was developed to support the site and remains home to generations of employees. The site is located on the traditional and unceded territory of the Algonquin Nation.

CNL is once again using leading-edge technology to put forward a long-term environmental solution. Taking guidance from domestic and international experience, CNL has proposed an engineered containment mound – the Near Surface Disposal Facility, or NSDF – as the solution for low-level radioactive waste at Chalk River Labs.

Read the case study.

Clayton Community Centre

Open design process meets high performance and needs of users

By Melissa Higgs

Located about 10km east of the Surrey City Centre, Clayton Heights is transitioning rapidly from a predominantly agricultural community to an increasingly urban one. Designed to feel like it is part of the surrounding forest, the Clayton Community Centre focuses on meeting the current and evolving needs of residents, with social gathering spaces that help foster wellness, connection and resilience.

The 7,000 m² (76,000sf) Centre combines four aspects of the City of Surrey’s community services – recreation, library, arts and parks — in a seamlessly integrated facility. Previously accustomed to operating out of their own separate buildings, the four programs pooled space and resources during the design process, maximizing the potential for positive impact on both the community and their own operations.

The social fabric of the surrounding context has informed a design that addresses the needs of young people, while providing key gathering spaces to support the development of overall community connections. The unique mix of spaces combines arts and culture programming including music studios, recording studios and a community rehearsal hall, with recreational activities including a gymnasium, fitness centre, and a branch library.

These services are supported by a range of shared social areas and a unique mix of supplementary spaces, imagined and developed in close collaboration with the community, and designed to allow for community-led programming. Clayton Community Centre initially opened its doors in February, 2021 with reduced programming due to COVID-19 restrictions, before opening fully in the summer of that year.

Community engagement played a crucial role in the design development. Rather than simply informing neighbouring residents of the building’s progress, the architectural team invited people into the process to shape its development. In the absence of a recognized independent standard, hcma created its own social impact framework based on principles of equity, social inclusion, sustainability and adaptability. Clayton Community Centre is the first building to have been completed using hcma’s framework from start to finish.

From the start, the project was aiming for ultra-low energy performance and ultimately Passive House certification. As most of the Passive House projects completed in North America have been in the residential sector, there are few completed non-residential projects from which to learn. By designing complex non-residential buildings, design professionals are charting new territory.

Melissa Higgs, Architect AIBC, FRAIC is a principal at hcma. 


Parcours Gouin Welcome Pavilion

A passive-active design brings urban beautification

By Maryse Laberge

Designed both as a visitor centre and as a showcase for environmental education, the Parcours Gouin Welcome pavilion integrates sustainable design  strategies, such as site preservation, potable water conservation, energy efficiency, renewable energy, local materials, and health and wellbeing. The Net-Zero project is certified LEED Gold.

The two-storey, 460m² building is located in the wooded Basile-Routhier Park, Montreal’s only riverside park accessible by Metro. The ground floor includes a community room that can accommodate various events, while the upper floor includes a large multi-purpose room, an office area for community organizations, the mechanical room and access to an exterior deck.

The site offers a variety of accessible services and facilities promoting outdoor activities, nature interpretation and healthy lifestyles, whether through nutrition or physical activity. The sustainable strategies used in the construction and operation of the building are demonstrated and explained to visitors. In addition, the biophilic design approach and the connection to the surrounding landscape are apparent throughout the building and contribute to the enjoyment well-being of the users.

Energy and Water

The ambition to achieve a Net Zero building is realized through a combination of strategies which include a high-performance building envelope, high-efficiency mechanical and electrical systems, and an array of 120 photovoltaic panels capable of generating 31.8 kilowatts of renewable energy.

Thermal comfort is achieved by minimizing thermal bridging through the highly insulated envelope, and the use of a radiant heating system embedded in the concrete slab. A ventilation and air conditioning system, controlled by occupancy sensors, also ensures excellent air quality and comfort. Operable triple-pane windows allow for natural ventilation when the weather is mild.

Water-saving appliances are used to reduce primary consumption. The domestic hot water is preheated by a solar collector on the roof (in which a heat transfer fluid circulates) before going into a holding tank. Rainwater management includes a rainwater collection tank for watering the gardens. Various stormwater management measures are integrated, such as permeable paving, bio-retention basins and rain gardens, and all are designed to fit harmoniously within the overall aesthetic of the building and its surroundings.

The energy-efficient curtain wall by Unicel Architectural contains triple-glazed sealed units, low-E film and interior wood mullions.

Maryse Laberge is Senior Principal at Beirtz Bastien Beaudoin Laforest (Groupe Provencher Roy).


Viewpoint: Dowel laminated timber: a step towards circularity in construction

By Sigi Liebmann

Wood is widely promoted as a renewable and  environmentally responsible material, based on the third-party certification of sustainable forest management (SFM) practices. While this can be successfully argued at the scale of the forest, until now, the argument has not applied equally at the scale of the building.

All durable wood products will store the carbon they have sequestered while part of a living tree, until destroyed by decay or fire at the end of their service life. However, this remains a cradle to grave evaluation that fails to consider the potential for reclamation and repurposing of the product, the GHG emissions associated with manufacture, and the potential environmental and health impacts of any adhesives used.

As mass timber fabricators, we believe that solid wood is the best material to build with from an ethical standpoint, and that using natural timber, as uncontaminated as possible, is the most sustainable approach to take for the planet and for future generations. This is why we chose to manufacture 100% wood, no-glue dowel laminated timber (DLT), a product that is 100% recyclable, reusable and does not produce contaminated waste.

DLT is a relatively new arrival in Canada, although it has been available in Europe for more than 20 years.  To produce DLT, layers of dimension lumber are assembled face to face. A hole is drilled through the entire assembly and a wooden dowel is inserted to hold it all together. No glue, no nails, just the wooden dowel. The wood boards have a moisture content of 10-15%, while the dowels are bone dry. As soon as the dowels are installed and in contact with the surrounding wood, they will absorb the moisture from the boards and expand. This forms a mechanical connection that is incredibly strong.

This type of assembly results in ‘stacked’ DLT panels, so called because ‘stacked’ is a direct translation of the German term ‘Brettstapel’. The surface appearance can be flat or fluted – the latter when 2×4 and 2×6 material is alternated.

In addition to stacked DLT panels there can be crossed DLT panels, a more environmentally responsible product than glue-bonded, cross laminated timber (CLT). In ‘crossed’ DLT, the large sized panels are manufactured by assembling multiple layers of lumber on top of one another, each layer being at different angles to the one below, and pegging them together with hardwood dowels. DLT need not be glued. Windows and doors are left open as the panel is laid up, rather than being cut out from a finished solid panel. This process minimizes the amount of ‘waste’ material produced. 

Sigi Liebmann is a Swiss trained master timber framer and owner of International Timberframes Inc. in Golden BC.


SABMag 73 – Winter 2021/2022

SABMag 73 - Winter 2021/2022



Natural resilience – Using Nature-based Solutions to Enhance Coastal Protection

By Joanna Eyquem

Coastal flooding and erosion are a direct threat to the health and safety of people living in coastal communities, and cause damage to local infrastructure and property. The majority of Canada’s coastal population is located along the East (Atlantic) and West (Pacific) coastlines, where sea levels are rising due to irreversible climate change. Read more …

Okanagan College – Health Sciences Centre

Model of healthcare education targets Net-Zero Carbon, WELL and LEED Gold certifications

By Peter Osborne

Located on a narrow brownfield site on the Kelowna campus of Okanagan College, the Health Sciences Centre includes technology-enhanced and student-centred labs, classrooms, and offices for health and social development programs. Read more …

Montreal Biodome

Interior redesign complements extant architecture with minimal use of materials

Housed in the former Velodrome constructed for the Montréal 1976 Olympic Games, the Biodome opened in 1992 and is a jewel in the crown of a consortium of facilities that collectively account for the most visited museum spaces in Canada. Read more …

Zibi Complexe O

One Planet Living project one step in reclaiming former industrial site

By Figurr Architects Collective

Located in both Ottawa and Gatineau, the Zibi development aims to be transformative physically, environmentally and socially. The only One Planet Living endorsed community in Canada, Zibi occupies formerly contaminated industrial lands, and is transforming them into one of Canada’s most sustainable communities. Read more …

Virtual Design and Construction – An Owner’s Perspective

By Robert Malczyk

In the 1990s, 3D modelling was introduced as a design tool that enabled architects to better visualize their projects and perhaps more importantly, to convey their ideas to clients and the public. The software has become so sophisticated that it is sometimes difficult to decide whether an image is a photograph of a completed building, or simply a rendering of one that is proposed. Read more …

The Annual Guide

LEED categories noted for the products listed in the following pages are intended to show how these products can potentially help a project earn LEED v4 points. Visit the directory here.

Interview with Jeff Gold of Nexus Circular LLC

Jeff Gold is the COO/founder of Nexus, the leading circular waste-plastics solution company based in Atlanta that converts landfill-bound plastics to reusable plastics.

1. What does Nexus do exactly?

Nexus converts waste plastics that are typically bound for a landfill or incineration into chemical feedstocks that are used to create new, virgin plastics.  We take the polyethylene, polypropylene, and polystyrene that cannot be economically recycled through mechanical systems and transform them into valuable liquids and waxes that our partners use to create a huge range of new plastic products.  Our process is very energy efficient and by directing our output into new plastics versus fuel products that are burned, we sequester the carbon in those plastics and prevent their entry into the environment as harmful greenhouse gases.

2. How does the waste plastics conversion work?

Nexus uses a process known as pyrolysis, or “thermal depolymerization” to transform waste plastic back into its basic molecular forms. This process works by applying heat to the plastic but excluding all oxygen so that instead of burning, the plastic simply liquefies and decomposes into a variety of hydrocarbon molecules. Most plastics are made of long hydrocarbon chains and pyrolysis provides a way to “cut” those chains into smaller pieces that become liquids or waxes once they are cooled.  It is these liquids and waxes that can then be used in the industrial systems that make new plastic resins.

3. Is the conversion process truly a ‘closed loop’?

We consider our process to be “closed loop” because all the plastic that goes into the system is converted into a new product that is captured at various points in the system.  For example, most of the incoming plastic is converted to liquids and a wax product that is collected and shipped off directly to our off-take partners.  The process also produces a flammable gas that we likewise capture and then use to heat the pyrolysis reactors.  A fourth product that results from the process is a carbon-black char material that forms in the reactors from small amounts of paper and cardboard that are mixed in with the plastic feedstock and from normal decomposition of plastic when it contacts very hot surfaces.  This char is collected and can be used as an asphalt additive. In this way, all the products formed from the plastic feedstock are converted, captured, and used in some way making the process truly closed loop.

4. What have been the challenges you have encountered?

Converting waste plastic at a commercial scale into useful products and doing so economically is very hard.

The principle technical challenges we have encountered revolve primarily around feedstock in terms of collection, contamination, and composition. The challenge has been to create a highly adaptable system that can accept a wide variation of inputs and produce a uniform, consistent, high-quality output.  Maintaining reactor performance in the face of a variable feedstock stream has also posed technical challenges around managing heat distribution to yield our desired products while minimizing energy consumption which is why we have taken all the learnings from our first plant and are now applying them to a third- generation design.

Another challenge involves proving that chemical recycling is a viable technology in the fight against plastic pollution.  There have been numerous press releases and announcements by groups in the chemical recycling space touting a solution that fails to materialize and when this happens often enough, a perception is created that this is something that does not really work.  While there is a lot of progress yet to be made, Nexus has shown that the technology can be effective and that it merits serious consideration.

5. What is the future? How far to do you see an operation like yours going?

We feel very optimistic about the future!  We have a team in place that has built an innovative and economic process that addresses the pressing environmental issue of plastic pollution and we have proven that Nexus is one of the few companies that can deliver our product at commercial scale and consistent quality.

Demand for our products is extremely high as many companies work towards satisfying consumer demands to increase the amount of certified recycled content in their products and take positive steps to improve the planet’s environmental quality.  Our challenge now is to scale the business at a rate that can keep pace with our customer’s needs, and to that end, we are working very hard to establish new locations both at home and overseas. Given that the use of plastics is expected to continue its upward trend over the next several,Nexus is poised to expand on its industry leadership position and play a major role in combatting plastic pollution for years to come.