Better buildings
September 16, 2021

Architecting resilience

How incorporating timber into buildings supports BC communities in the face of natural disasters

. The Steveston Fire Hall i

RESILIENT AND READY | When the City of Richmond decided to replace the 40-year-old fire hall serving the Steveston community, they did so with an iconic project built with structural wood panels formed using mountain pine beetle wood. | Photo credit: hcma

Today’s fire halls, police stations, health care facilities, schools, and community centres in BC are designed to meet rigorous seismic requirements, to withstand the impacts of a natural disaster—and often serve as post-disaster hubs. Increasingly, these facilities are being built with BC wood products, using newly developed systems and innovations, offering durability and resilience in the face of earthquakes, wind, and fire. These buildings are designed to meet post-disaster standards and able to resist seismic forces 1.3 to 1.5 times those for a regular building.

Be prepared

Designing for disaster with wood

A post-disaster building or hub is defined as a facility that is essential to the provision of services in the event of a disaster. This means it will be built to a seismic design load that is considerably higher than typical residential or commercial buildings. After an earthquake, the building will, in an ideal scenario, be able to be safely re-entered and used to deliver emergency services. Other essential service buildings in BC are also built to post-disaster standards to avoid interruption of critical resources. This includes energy centres, supportive infrastructure and hydropower operations centres. Increasingly, these facilities are being built with wood, offering natural resilience and durability in the face of earthquakes, wind, and even fire. These buildings are designed to meet post-disaster standards and able to resist seismic forces 1.3 to 1.5 times that of a regular building.

One such example is the Merritt Fire Zone Office and Provincial Wildfire Training Centre. The facility provides space for up to 58 staff, storage areas for firefighting equipment and three classrooms to support field training. The courtyard functions as an outdoor training facility, a gathering place for crew members and shelter from the strong westerly prevailing winds. The two-storey structure consists of a glue-laminated (glulam)-post-and-beam system with engineered wood trusses and cross-laminated timber (CLT) for the roof and canopy decking.

Left: Merritt Fire Zone Office and Provincial Wildfire Training Centre | Photo credit: Ema Peter Photography courtesy Kaisan Architecture

A natural performer

Wood’s durability and resilience over the ages

Ancient wood buildings continue to stand including 8th-century Japanese temples, 11th-century Norwegian stave churches, and the many medieval post-and-beam structures of England and Europe. They demonstrate wood is a naturally strong, lightweight, durable, and resilient material that has stood the test of time.

We see it in nature. Trees can tolerate great forces inflicted by wind, weather, and natural disasters. This is possible because wood is made up of long, thin, strong cells. It is the unique elongated design of these cell walls that gives wood its structural fortitude. Cell walls are made of cellulose, lignin, and hemicellulose. When converted to wood products, these cells continue to deliver lightweight, nimble, structural solutions with a strength comparable to other building materials.

Wood products can withstand considerable force—particularly when compression and tension forces are exerted parallel to the wood’s grain. A single Douglas-fir square, 9 cm x 9 cm, can support nearly 10 tons in tension and compression.

 

Consequently, despite their lighter weight, wood products can withstand considerable force—particularly when compression and tension forces are exerted parallel to the wood’s grain. Wood’s strength and ability to flex make it well-suited to withstanding earthquakes, when combined with good seismic design. 

And today’s modern wood-frame and mass timber buildings have a proven fire safety record. In the event of a fire, mass timber and engineered wood products char on the outside, forming a protective layer while retaining strength. This slows combustion significantly, allowing time to evacuate the building safely. Effective design and the use of state-of-the-art fire protection technologies in timber structures provide added assurance and help save lives. So much so, many BC fire halls are built with wood. 

Right: Horyuji Temple, Zhenzhong Liu | Photo credit: Zhenzhong Liu courtesy Unsplash

Lighten up

Is a light-weight building material, such as wood, more resilient during an earthquake?

Cristiano Loss, Assistant Professor in Timber Engineering Associate Chair in Wood Building Design and Construction at The University of British Columbia specializes in the resilience of high-performance wood-based systems and structures in the face of earthquakes. Involved in experimental testing of timber assemblies, he points out the inherent benefits of such systems. “One of the things that makes timber more resilient, by far, is its lighter weight. You might think this is a minor point, but it’s actually a big advantage,” he explains. “Wood is five times lighter than concrete, reducing seismic forces on a building considerably.” He points out another advantage of wood systems—their tendency to be an exposed system of connections. “The fact that you don’t have any rebar merged into the material or system, you can detect damage quite easily. As long as you have the connection well-defined in the system, timely repair is possible.” Loss is spearheading further research to help industry adopt performance-based design methods for hybrid mass timber structures—approaches that could lead to quick assembly and large-scale production of structural components that significantly limit damage during natural disasters such as an earthquake or high winds.

Fast + Epp Headquarters interior | Photo credit: Mathias Fast Photography

Firing on all cylinders

Hybrid-timber-built high-tech fire halls take the heat

Today’s modern fire halls have come a long way from the quaint, masonry structures of the past. Characterized by bold architectural designs, high-tech materials, exposed mass timber, and advanced technologies, these critical civic facilities serve communities every day but also as essential post-disaster hubs for the province.

A most recent example—and thoroughly state-of-the-art interpretation of this building typology—is the newly completed Prince George Fire Hall No. 1. Its hybrid steel, concrete, and wood structure accommodates five truck bays and the latest in modern firefighting equipment. Its resolute contemporary form, clad with a carbon-black coloured siding, features a graceful swoop to its roofline.

Left: Prince George Fire Hall No. 1 exterior | Photo courtesy the City of Prince George

“We created a very simple clean form that, as you drive by, you recognize it, very powerfully as the region’s fire hall,” said Stuart Rothnie, of hcma and principal-in-charge of the project. 

“Most people don’t even think about the fire service until they need it, but we felt it was important for the building to have a strong civic identity. It’s reassuring to the community that the facility is there for their safety and protection—something I think the design of the Prince George Fire Hall achieves,” adds Rothnie. 

This use of timber is not only an homage to the importance of forest products to the local culture and economy—it demonstrates that wood products are a trusted, fire-safe and durable material well-suited to this building type.

 

Wood is showcased in the building’s design. The front-entrance feature stairwell makes a bold impression, its nail-laminated timber construction (NLT) literally wraps occupants’ floor to ceiling with the warmth of wood. Crews used more than 100,000 fasteners and over 3,000 pieces of lumber to construct this component of the facility. The large expansive truck bays are constructed using a laminated veneer lumber (LVL) roof. Aesthetically pleasing, the overall use of wood offers visual warmth, complementing the building’s dark exterior cladding. Mass timber products, such as NLT and LVL, are fire-safe—if exposed to flame the materials chars, forming a protective layer. 

Right: Prince George Fire Hall No. 1 | Photo credit: hcma

SPARKING NEW DESIGNS

Features of the modern fire hall

Serving as a post-disaster facility, the Prince George Fire Hall No. 1 incorporates the use of mass timber along with the latest in fire hall best practices and design. 

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Bold civic landmark

A thoroughly state-of-the-art interpretation of the fire hall building typology, its contemporary design makes a civic bold statement.

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Mass timber hybrid structure

Features a mass timber hybrid roof structure—LVL structure and NLT stairwell—made up of 3,000 pieces of lumber.

Seismic waves icon

Earthquake-resistant 

Designed to meet post-disaster standards and able to resist seismic forces 1.5 times those for a regular building.

Post-disaster hub icon

Post-disaster hub

Serves as a critical gathering hub for key decisions makers in the region in the event of a disaster.

Fire Chief John Iverson talks about Prince George's new fire hall and how its features and improvements will help firefighters keep residents safe in decades to come.

More than 800 km south, near the province’s capital, the District of Saanich is in the design phase of a similar facility, that will feature a hybrid mass timber structure and meet the post-disaster requirements set out by BC’s building code.

It is one of the first mass timber buildings in Canada to target a zero-carbon building standard while being fully equipped for post-disaster response. It will serve as a demonstration project and template for future post-disaster buildings. The project will target LEED Gold (with the aspiration to reach Platinum), CaGBC Zero Carbon Building Standard, and the BC Energy Step Code Level 2. The project will replace the present one-storey, 353 square-metre building with a two-storey 2,190 square-metre structure that will accommodate eight apparatus and emergency vehicles. 

The choice to use mass timber demonstrates the Saanich Fire Department’s confidence in the material’s safety and performance. “In my experience a lot of the mass timber buildings I’ve responded to after significant fire incidents usually remain standing. Most of the timber or the heavy timber portions are simply just charred, and a good portion of the structural integrity of the building remained,” said Dan Wood the Deputy Fire Chief for the Saanich Fire Department. 

Left: District of Saanich Fire Station #2 Redevelopment | Rendering courtesy hcma

Fired up

BC fire halls feature mass timber designs

 

From Prince George and Saanich to Steveston and Qualicum Beach, mass timber is increasingly being used in fire halls and related facilities throughout the province. This use of timber is not only an homage to the importance of forest products to the local culture and economy—it demonstrates that wood products are a trusted, fire-safe, and durable material well-suited to this building type.

Steveston Fire Hall No. 2 | Photo credit: hcma

The mass timber hybrid building will use a steel and timber post-and-beam system supporting CLT floors, a CLT roof suspended from glulam beams, and a mass timber shear wall. The suspended CLT roof supported by an upstand glulam beam leaves a void that can accommodate additional insulation, improving the overall thermal performance of the building. The suspension system will require a unique connection design replicated through the entire roof and could be developed as a typical connection to be used on future projects. Select portions of exposed mass timber will add warmth and character to the design. 

“I’m excited about the use of wood and wood from BC. Not only is it easy to work with and a lot of the preconstruction of the mass timber systems done offsite—when designed correctly, it can withstand seismic and lateral forces more substantially than steel, and concrete because it weighs quite a bit less and has a little more flexibility,” said Wood. 

Right: District of Saanich Fire Station #2 Redevelopment | Rendering courtesy hcma

School of hard knocks

Education facilities built for resilience

Today’s schools are increasingly being built to be more durable and withstand the hard knocks of natural disasters, such as earthquakes. Over the past number of years, British Columbia has invested in making the province’s schools seismically sound and in certain cases able to serve as critical post-disaster hubs for the communities they serve.

This is thanks in part to funding provided through Natural Resources Canada’s Green Construction through Wood (GCWood) Program, which encourages the use of wood in non-traditional construction projects, such as tall wood buildings, low-rise non-residential buildings, and bridges. The initiative includes two new schools in the Lower Mainland—Bayview Elementary School and Sir Mathew Begbie Elementary School—part of a Vancouver School Board pilot project for incorporating mass timber into schools. 

Left: Bayview Elementary School Seismic Replacement | Rendering courtesy Francl Architecture

Bayview Elementary School’s mass timber structure makes for an efficient floor plan on a compact site—the exterior and structural walls, floors, and roof use CLT complemented by glulam columns and beams. Left exposed, the wood adds warmth and character to interior spaces. To foster collaborative learning spaces, classroom volumes are staggered and the corridor widened—allowing for break-out rooms, seating, hang-out space, and a larger learning commons. The library opens up to the corridor for added flexible space and informal learning. The CLT system serves double duty as both gravity and shear walls, to resist the high seismic forces of the region. For the gymnasium and multipurpose room a composite double-T design combines CLT with glulam beams to form 16 metre-long spanning panels. 

Right: Bayview Elementary Seismic Replacement, mass timber installation | Photo: Wade Comer Photography

Not far from Bayview Elementary is Sir Mathew Begbie Elementary School. The new school, which replaces an original structure on the site built in 1922, is part of the BC government’s initiative to accelerate seismic safety in schools by means of upgrades and replacements of facilities. It’s long-spanning mass timber forms the school’s quadrant configuration, while accommodating well-designed way-finding through the building with north/south and east/west corridors. Again, CLT serves as both gravity and shear walls, to resist the high seismic forces of the region. Non-structural partitions within the interior accommodate mechanical, electrical, and plumbing systems. Large door openings in the CLT walls connect each classroom with the common spaces of each pod. 

The CLT-built structure delivers a cantilevered design for the multipurpose roof, a composite double-T design combining CLT with glulam beams for long-spanning panels. The system accommodates open spaces with a shallow structural depth. For the large gymnasium, long glulam beams are moment connected to create a striking vaulted roof. 

Left: Sir Mathew Begbie Elementary School Seismic Replacement during construction | Photo credit: Bright Photography

Expert insights

How mass timber can boost the resilience of schools

Nick Round

Nick Bevilacqua, principal at Fast + Epp, shares his insights on the future of school design in BC and beyond. He has a broad range of experience in all building types and is currently working on a number of school projects throughout the province featuring innovative timber construction.


Q: What are some of the seismic advantages of mass timber hybrid building systems?

A: One of the nice things that mass timber construction has going for it is that we tend to try to expose as much of the structure as we can. This makes the post-disaster inspection of these structures a lot more straightforward. Fail points tend to be at the metal connections and this is the type of thing that you could possibly retrofit a little easier than other structures. Concrete tends to be challenging to assess after a seismic event. You’re looking for cracking and failure in the rebar—things that can be tough to spot quickly, especially when the structure is concealed.

Q: What role can wood and natural materials play in the design of future schools?

A: These two schools, Sir Mathew Begbie Elementary School and Bayview Elementary School serve as great examples of the potential that can be realized with mass timber construction. In addition to meeting the demands of the seismic mitigation program, the timber framing systems used in these buildings provide warm, inviting spaces for the school community as well as help the school board meet their sustainability objectives.

At this point, the biophilic advantages of using naturally occurring materials such as wood in school design are well understood in the education community. There have been a number of publications, including a study Wood Use in British Columbia Schools that we completed with Stantec in 2018, that have helped foster this awareness within the community.

Cracking the code

Understanding BC’s building code and resilience

The BC building code sets out four “importance categories” relating to loads for buildings for resilience and post-disaster readiness. See BC Building Code Table 4.1.2.1. Importance Categories for Buildings for a complete list.

Low importance

Low

Buildings that represent a low direct or indirect hazard to human life in the event of failure, including low human-occupancy buildings, where it can be shown that collapse is not likely to cause injury or other serious consequences and minor storage buildings.

Normal Importance

Normal

All buildings from residential, commercial, office and industrial except those listed in Importance Categories Low, High and Post-disaster.

High Importance

High

Buildings that are likely to be used as post-disaster shelters, including buildings such as an elementary, middle, or secondary school or a community centre.

Post-disaster importance

Post-Disaster

Post-disaster buildings are buildings that are essential to the provision of services including hospitals, emergency treatment facilities, power generating stations, public water treatment facilities, fire, rescue, and police stations and communications facilities, including radio and television stations.

Tough as nails

Energy and operation facilities designed for resilience

Energy and operations facilities are some of the most essential services that need to remain resilient and in working order in the face of disaster. A continuous power supply, clean water, sewage systems, and other key utilities are critical to seeing communities through events with impacts that can affect daily life for weeks, even months. And when built with wood and sustainability in mind, these facilities can also contribute to the long-term resilience objectives of curbing emissions and the impacts of climate change. 

One example is Alexandra District Energy Utility Expansion, a Richmond-based high-tech geothermal utility building. Wood is used throughout the building, as a structural element and finishing feature. Yellow cedar cladding was used on the exterior, sourced from naturally fallen trees. CLT wall and roof panels and glulam beams and columns were chosen to achieve the significant spans and clear heights required by the large equipment housed inside the building. 

Seismically, the building is designed to post-disaster standards, able to resist seismic forces 1.5 times those for a regular building. The CLT system also offers resilience in the form of flexibility and future expansion—it was easy to cut and configure to the complex cabling and pipping in the facility. 

Left: Alexandra District Energy Utility Expansion | Photo credit: Michael Elkan

Going Strong

Resilient public infrastructure using mass timber

Mass timber is increasingly being used in public infrastructure throughout the province, its seismic performance backed up by research. Testing shows the seismic performance of mass timber buildings systems, such as CLT platform-type walls, is directly impacted by the choice of connectors and fasteners. FPInnovations studied the seismic performance of 11 different types of CLT walls that can be used for platform-style construction. These configurations included single panel walls with three different aspect ratios, multi-panel walls with step joints and different types of screws to connect them, as well as two-storey wall assemblies.

Results showed that CLT walls can have adequate seismic performance when nails or screws are used with the steel brackets. Use of hold-downs with nails on each end of the wall improves their seismic performance. A key finding: walls with hold-downs offer significantly better seismic performance and improved energy dissipation. To determine how a 3D structure would respond to seismic forces, the FPInnovations team tested a two-storey platform-type CLT house (symmetric in one direction and non-symmetric in the other direction). The structure sustained a combination of rocking and sliding deformations, with the main deformations found in lap-joints, brackets, and hold-downs. Overall, structural integrity was not comprised at failure and the bottom storey experienced a drift of about 3.2 percent according to a presentation given by Marjan Popovski, Senior Scientist, FPInnovations.

Merritt Fire Zone Office and Provincial Wildfire Training Centre | Photo credit: Ema Peter Photography courtesy Kaisan Architecture.

Looking ahead

Wood’s bright and resilient future

As advanced hybrid-timber building systems continue to grow in popularity—and in height—structural engineers, such as TobiasF Fast of Fast + Epp, foresee a future of no-damage resilient buildings that not only save lives during an earthquake but can remain safe to occupy afterwards. And that future may not be too far off. 

Fast’s firm incorporated such a system into their newly completed head office, a four-story hybrid mass timber structure located in the heart of Vancouver’s Cambie-City Hall neighbourhood. 

The technology is a no-damage system born out of the Christchurch earthquakes in New Zealand. The device self-centres following a seismic event, allowing a structure to withstand an earthquake and any following aftershocks. 

The technology can be applied to new or existing structures, requires no post-event maintenance, and is cost-effective and compact. And as Fast points out, it’s ideally suited to the lightweight advantages of mass timber buildings.

“A mass timber building is typically quite light. The inertial forces that you get are proportionately lower. That means less demand on your shear walls, less demand on braces, on these shock-absorbing devices.” 

Fast + Epp Home Office Exterior

Above: Fast + Epp Headquarters street-view, Photo credit: Michael Elkan Photography courtesy Fast + Epp | Left: Fast + Epp Headquarters mass timber installation | Photo credit: Mathias Fast Photography courtesy Fast + Epp

 

When it comes to resilience and seismic design, Fast explains concrete is subject to degradation and corrosion. “There’s absolutely a need for concrete in most structures but certainly mass timber can replace a significant portion. And when combined with technologies like these specially-designed shock-absorbing connectors these sustainable renewable building systems can be made resilient, saving lives and virtually eliminating damage to allow for re-entry after an earthquake.”

Fast + Epp’s use of the technology extends to a tall wood project, 2150 Keith Drive, that uses a timber braced frame and CLT shearwall systems. 

And Fast’s firm isn’t alone in its use of this technology with mass timber. Merely blocks from Fast + Epp’s office, Robert Malczyk, principal at Timber Engineering Inc. is also making use of Tectonus in their mass timber commercial office building oN5.

 

Right: oN5 | Rendering courtesy Hemsworth Architecture 

Shaking things up

Cutting-edge technologies and mass timber design offers exceptional seismic resilience 

A four-storey office building in the heart of Vancouver’s Cambie and Broadway urban hub showcases cutting technologies and demonstrates just how resilient a mass timber structure can be in the unfortunate event of a major earthquake. Specially-designed connectors have been installed at the base of the CLT shear walls to act as shock absorbers, ‘snapping’ the building back into position without damage after a significant earthquake and allowing for an immediate return to occupancy. The connectors are left uncovered, along with exposed timber as the interior finish, as part of Fast + Epp’s concept lab initiative for ongoing research and testing.

Image courtesy Tectonus Resilient Seismic Solutions

 

 

Fast + Epp is going one step further and has turned its own offices into a living concept lab, supported by software and digital apps. This gives them the ability to test and demonstrate advancements in mass timber engineering, with the ultimate goal of sharing their findings with the broader design community. 

Along with industry, the Province sees an opportunity for BC to lead when it comes to mass timber and resilient design. 

“I’m quite curious about the possibility of a hybrid approach where there are elements of mass timber and elements of other forms of biomass, more sustainable concrete with CO2 absorption and steel. I think that is where the great innovation will happen in the coming years as we shift towards more renewable, eco-friendly resilient building design,” said Andrew Pape-Salmon, former executive director of the Province’s Building and Safety Standards Branch and Adjunct Professor at UVic Civil Engineering.

 

“Mass timber innovation in British Columbia holds the promise of positioning our design professionals, product manufacturers and developers to be global leaders and to implement these applications worldwide,” adds Pape. 

The future of mass timber building design in BC is bright and resilient.