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Tag: Interview

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Interview with:


Architect Vince Catalli on the Circular Built Environment (CBE) and the new standard to define it.

What is the CBE?

Circular is the key word in defining the CBE which is modelled after cycles in nature that continuously use and transform materials without waste. According to the World Green Building Council, a circular building optimizes the use of resources while minimizing waste throughout its whole life cycle. The building’s design, operation and deconstruction maximize value over time using:

1. Durable products and services made of secondary, non-toxic, sustainably sourced, or renewable, reusable or recyclable material;

2. Space efficiency over time through shared occupancy, flexibility and adaptability;

3. Longevity, resilience, durability, easy maintenance and reparability;

4. Disassembly, reuse or recycling of embedded material, components and systems; and

5. Life-cycle assessment (LCA), life-cycle costing (LCC) and readily available digital information (such as BIM that capture building material passports)

This sounds like Waste Management and reducing Embodied Carbon, what is the difference?

Waste Management and reducing Embodied Carbon are components of CBE. The CBE proposes systemic changes in business models which have historically been linear by using many integrated approaches (i.e. durability, waste reduction, refurbishment, remanufacturing, recovery, reuse, reduction of embodied carbon, etc.).

Pursuing the CBE is critical for North America to stay competitive with other nations (i.e. the EU, Japan, Australia, etc.) that are already working towards the CBE. Eliminating waste is very cost effective and good business.

Why are you involved within the CBE national discussions?

Since 1994 I have focused on new approaches within our industry that were precursors to CBE:

• I looked at Deconstruction via a pilot project for Canada Mortgage and Housing Corporation (CMHC) in 1996 which then led me to develop a Design for Disassembly and Adaptability guide in 1998.

• I was part of a committee that developed two new standards with Canadian Standards Association (CSA) (Z782-06 and Z783-12). These were global firsts that led to international developments in ISO Standards.

Why a Definition oriented CBE Standard?

In my recent work (2021) with CSA, I spoke with various private and public stakeholders from across Canada. I found that the CBE was unfamiliar to them, but they were unknowingly engaging with or operating in circular systems. They spoke of circularity in terms of waste management, Net Zero, embodied carbon, CO2 reduction, climate change, resilience, etc. Everyone was using different terms and approaches, lacking cohesion on a national level. A standard to define the CBE will give all actors in the building industry unified tools to focus our attention, coordinate and mobilise in ways that create lasting change.

Why is it important to move the CBE ahead now?

Our industry consumes about 50% of virgin resources extracted annually and produces close to 40% of global CO2 emissions. Finite resources will become scarce and climate change will impact how we build due to wasted embodied carbon. CBE will allow industry to redesign our approach to materials applied in construction, factoring in disassembly and adaptability so that we recover materials. We cannot continue as is, we need to recover value and “future proof” building assets. It just makes sense, right?

What can the building Industry do to move the CBE ahead?

All stakeholders need to learn about the CBE with the goal of achieving systemic change. This will lead us into action, education, new skills and application, required collaboration throughout the industry. Much like the early 2000s with green buildings, the CBE will lead us into the next chapter. A national discussion is needed to review how this will emerge. I don’t see an option but to get involved as we all have a role to play.
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Interview with Mike Manning and Catherine Marshall

The husband-and-wife team at Greenbilt Homes (greenbilthomes.ca) have turned their attention to FlexPlex® – their multiplex building that easily flexes from duplex, triplex, fourplex to single-family. This is a new venture for this 15-year-old Passive House company. Traditionally, Greenbilt has been a custom home builder working with both modular and conventional technology.

1. How did you get the idea for FlexPlex

We started ruminating about multiplexes when our kids were teenagers as a way that they could generate the rental income to afford to own a place. But we wanted them to have the option to enlarge their personal area by removing space from the rental area. Eventually, we came up with a “FlexPlex” prototype. We decided to build a duplex version for ourselves as both our retirement home, and as a retirement income generator. Our FlexPlex could also turn into a single-family multigenerational home if the “kids” have kids and want to live with “Mom and Dad”.  We’re waiting!

2. How did you develop a flexible design and how does it work?

We designed a four 2-bedroom apartment building. Then we stress-tested the building infrastructure by seeing how it would work in a duplex, and a single-family home. We also focused on the aspects of each configuration that make it work and adjusted the design accordingly. There are so many ways the building can flex from one configuration to another, so we’ll give you one example.

If we wanted to turn the upper duplex into two 2-bedroom apartments:

Floor 1: use hidden infrastructure to add an extra bathroom, and in-suite laundry; frame two interior walls and open up a hidden doorway in an existing wall; and move one door.

Floor 2: use hidden infrastructure to add a kitchen; move one door.

3. How can owners benefit from FlexPlex features?

Many buildings become functionally obsolete because they were designed with a single purpose. For example, office buildings with large floorplates likely can’t be adapted to another use. Because of the floorplate and the infrastructure, renovation to change the FlexPlex are quick and easy.

As the FlexPlex can have up to eight bed/bath combinations and four kitchen/food prep areas, there’s a lot of optionality in the design. This building could have multiple configurations as a residence. In addition, it could be a small institutional or hospitality building. 

4. It seems unusual to copyright a construction process.

Why did you do that?

We wanted to protect our IP. But regardless of the legalities, now that we have given SABMag the drawings of the four-unit design, our secrets are out. Perhaps a better question is “why are you sharing this proprietary information?” We are getting toward the end of our careers, and we decided to try to inspire others in sustainable design to keep pushing forward with new ideas. We feel that it’s socially imperative for more innovation to occur to densify sustainably and affordably. We won’t maintain social cohesion if new housing sells at $1,600 per square foot. 
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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.

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