Amsterdam-based sustainable building design and consultancy company Arcadis NV is fully committed to decarbonizing the built environment, a mission being spearheaded by noted architect Pablo La Roche, director of the company's sustainable design division based in California.

Last year, Arcadis became a major player in Canada with the acquisition of Toronto-based IBI Group, the technology-driven design outfit which has long been one of this country's most innovative architectural and engineering firms.

La Roche, who also serves as architecture professor at Cal Poly Pomona, is one of the world's leading authorities in nature-based solutions to the built environment and is a fierce crusader for sustainable design, which he sees as merely the first phase in net-zero building development. 

"Sustainability is the starting point, but it's not enough. We need to go further and that's what I am seeking to accomplish with our projects," La Roche said in an interview with Sustainable Biz Canada.

"Sustainability is based on the idea of doing less harm to the environment, but that can also take the form of a code-compliant building that is simply the best low-carbon design the architect can get away with without going to jail. You didn't do anything special."

"There are varying levels of impact in sustainable design. But if we really want to do something good, let's do regenerative design, let's carry out climate-positive design, something that will make the environment around the buildings better than it was before . . . and enhance the quality of life for those who live and work in those spaces."

Regenerative design – taking sustainability to the next level

According to La Roche, a sustainable building represents merely the bare minimum of what existing engineering and construction technology can achieve. Such buildings may have a lower impact on the environment due to energy and water conservation measures, for example, but they will still have some residual impact according to how "green" the building happens to be. 

The next step up is the net-zero or zero-emissions building (ZEB) which has no negative environmental impact whatsoever. According to a recent European Union proposal, a new ZEB requirement set to take effect in 2030 will define such structures as those with very high energy performance. 

This means the very low amount of energy required to operate the building is fully provided by energy from renewable sources, with no on-site carbon emissions from fossil fuels.

La Roche believes however great the environmental benefits of low-carbon buildings, architects and project developers are equally capable and duty-bound to take the next step by adopting principles of "regenerative design."

He defines a regenerative design system as one in which all elements are interconnected, and each element is dependent on the others and will benefit each of the elements within the organic whole. 

This reflects his philosophical view that humans, nature and the built environment are all interlinked, co-dependent and part of a single system. He believes architecture needs to embrace this principle by designing resilient buildings and living spaces that enhance the ecosystem and harmonize the relationship between nature and humans.

"Cities suffering from urban heat island effect — an increase in temperature due to a dense concentration of buildings and pavement — can be up to 10 degrees warmer than surrounding rural areas, creating higher pollution levels and increasing illness and death.

"In response to this, establishing and expanding green spaces can help cool the environment while also acting as a carbon sink, offsetting some of the carbon accumulation in urban areas with significant sealed surfaces such as sidewalks and buildings," La Roche said. 

"Only one square meter of green roof is needed to offset a car’s annual particulate matter emissions . . . Plants are, in many ways, already working with us to respond to climate change. They trap carbon, reduce temperatures, catch pollutants, purify water and recover soils after natural disasters." 

Arcadis, others increasingly embracing sustainability 

With its acquisition of IBI Group, Arcadis is signalling its interest in growing the sustainable design sector in Canada as well as in the U.S. This is the kind of strategic vision La Roche believes will encourage other project developers to jump on the bandwagon.

"Arcadis has a shown a real commitment towards doing sustainable buildings and so there's definitely support and the purpose to do the right thing. I feel that everyone that I've worked with on the inside at Arcadis wants to do the right thing," La Roche said.

"That hasn't always been the case, of course . . . I've been doing sustainable architecture for almost 30 years, before the notion had gained currency. In those days I was seen more like this strange guy doing all of this, you know, oh, this sustainability work. Now things have changed dramatically. Our clients at Arcadis have realized that sustainability is incredibly important and that's why we're able to move forward."

CURV sets highest standard in large scale green building construction

La Roche cites downtown Vancouver's innovative CURV project, conceived by Montreal-based developer Brivia Group, as an example of the promise of sustainable architecture and design. Expected to break ground in 2024, CURV will stand 60 storeys, making it the world's tallest Passive House building.

Passive House-certified structures consume 90 per cent less heating and cooling energy than new buildings are required to use. This is accomplished by means of advanced HVAC systems, passive heat absorption and ultra-high insulation. Once completed, CURV will generate the least amount of carbon emissions of any comparable structure.

"CURV is an interesting project that combines aesthetics with performance. It's also a prime example of a high-performance building that implements Passive House principles developed by the Passivhaus Institut in Germany," La Roche explained. "The philosophy behind CURV is to create an asset for the city and for the community to work and live in. 

"This is an important case where you're designing a building that needs to adhere to a tight architectural envelope, where you're using high performance glazing, no thermal bridges and a mechanical system that uses a heat recovery system that allows you to reuse a portion of the energy generated.

"CURV is ideally suited to work in cold climates like Canada where you don't want a leaky building, one where you have draughts. In those cases you need to provide heating from mechanical systems to compensate for these currents of cold air coming. A tightly sealed building in the winter makes it much more energy efficient in combination with heat recovery systems."

Carbon-neutral design solutions promote wellness

In 2012, La Roche published his book, Carbon Neutral Architectural Design. The third edition will be released early in 2024, and will likely continue to influence architects at this critical juncture in the struggle to achieve net-zero.

To this end, La Roche is working on new projects that incorporate elements such as natural light, water, plants, natural materials such as wood and stone, textures, patterns and shadows into the new built environment.

"Studies show that green spaces directly affect the cognitive development of children and promote self-control behaviours. Inner-city landscaping in the forms of greenways and parks also encourage active travel and physical exercise, while gardening has shown to offer cognitive benefits to seniors."

Mass timber: An alternative to carbon building materials

La Roche also cited the overwhelming need to lower a building's carbon emissions at one end of the built spectrum while reducing embodied carbon at the other.

Buildings generate nearly 40 per cent of the earth's greenhouse gas emissions and architects and developers are coming under increasing regulatory and shareholder pressure to undertake lifecycle assessments, study environmental product declarations and select the lowest carbon materials available.

Traditional building materials such as cement, steel and aluminum have a lot of embodied carbon and now architects are seeking alternative materials such as mass timber.

"Mass timber has the advantage of being a material that is the reverse of embodied carbon," La Roche observed. "Whenever we use steel, aluminum, or concrete, there's energy embodied in the fabrication of these construction materials which means that there's carbon embodied in those materials.

"Timber is the opposite, because timber took carbon from the atmosphere to grow. That makes it a sequesterer of carbon. Imagine if we could have more materials like that – the applications are incredible.

"But of course the use of mass timber as an alternative construction material is only valid if you're harvesting the wood sustainably, from forests designed for that purpose. The idea doesn't hold if you're bringing the timber from the Amazon and helping destroy the rainforest . . ."

"When we talk about sustainability, we consider many factors, but I would say the most important element should be total carbon. We have to look at both embodied and operational carbon and marrying these two things together is the approach we should be taking.

"Sustainability should address the entire spectrum of the built environment. It shouldn't be restricted to expensive projects. Sustainability needs to encompass all types of buildings, including affordable housing. And while we're talking about sustainability, what about those people who don't have housing? How can we address their needs in some way. I wish we could also develop solutions for them."