Sustainability

To Push the Envelope on Sustainability, Push the Envelope

Higher education has historically led other markets, regarding their prioritization of sustainable practices, particularly green buildings. Often, campuses are testbeds for architectural innovation, as they are ripe ground considering their goal to convey an image of excellence, used to attract students and faculty, the benefits and operational savings are fully realized through the long-term ownership of buildings and grounds and because they are often used as teaching tools: learning-on-display for designers, backdrops for artists and even as settings for student activism urging deeper climate action.

windmills 

Nearly 700 nation-wide campuses since 2006 have agreed to address climate change through adherence to The American College & University Presidents’ Climate Commitment (ACUPCC), addressing resiliency, climate action planning and carbon neutrality by or before 2050 — a precursor to similar plans adopted by cities and states bound by the Paris Agreement. This is a major challenge that will impact four key areas: 1) new construction and existing buildings, 2) power generation and distribution, 3) waste and 4) transportation, as well as other behavior and procurement attributes. This article will focus on the first two points — specifically the first.

Carbon-Free Campus

A carbon-free campus, city or building is simple in theory: electrify all buildings (and vehicles), make them as efficient as possible and supply their electricity via a smart, renewably based (decentralized) power grid. The challenge comes in practice, as only 600 of the millions of existing buildings in North America are net-zero energy and because our centralized national energy matrix features only 17.5 percent renewables.

For power, many institutions — driven by ACUPCC — procure green power (wind and solar) via large-scale, often offsite, power purchase agreements (PPA). PPA’s require institutions to inventory their total greenhouse gas emissions, whereby then, they agree to purchase the determined amount from the grid wherever it can be most effectively generated by the renewable energy source. This makes sound fiscal sense, as it alleviates the institutions having to invest upfront in land and infrastructure, it creates a market for clean energy where it can be most efficiently produced (useful granted our current nationally centralized power grid), and by locking in the price for energy for 20 years, institutions are saving on operating costs, given that the price of energy continually rises. This low-hanging fruit is one of the most popular means by which campuses adhere to ACUPCC, and it is a win/win for both the environment and campuses.

solar pannels 

Courtesy of Stantec

Example of an offsite renewable energy farm, which is an opportunity for campuses to cut emissions and operational costs.

Buildings' Role

The waste and transportation components are important too. Most campuses offer recycling, so, to get to zero-waste, they should collect all eight LEEDv4 recycling streams and compost through a combination of centralized and decentralized methods, appropriate on a campus-by-campus basis. For transportation, campuses should put pedestrians first, promote active design guidelines, switch their fleets to renewable fuel sources and limit/reduce single car/combustible-vehicle use through policies, pricing, design, etc.

Buildings play a role here, as they foster the place where these elements interface with users. They play an even larger role given they are the primary users of energy and emitters of greenhouse gases on campuses, representing both the largest challenge — and opportunity for efficiency — and are the area where designers exhibit the greatest level of control. Tools like LEED, WELL and Passive House — even the Living Building Challenge in some rare instances — have been leveraged to positively impact sustainability, health and resiliency on campuses. However, these tools — spare the Living Building Challenge — while more advanced than code, do not address carbon-free building and campus-level emissions. To get there will require a combination of net-zero energy (and energy-positive) new construction in conjunction with the retrofitting all existing building stock — thinking beyond LEED Silver, even Platinum, towards net-zero/positive emissions.

solar panels in parking lot 

Front-Loading Design Process

Architects continue to design buildings much the same way they always have; yet, a carbon-free future will require new practices, namely true, front-loaded integrative design. Also, campuses will have to aim beyond LEED-based codes towards performance-based standards, like Passive House, to achieve this shift with less reliance on active building systems to do the work of achieving efficiencies towards passive architectural systems doing the heavy lifting. This places greater emphasis on the building envelope than codes of systems, like LEED. The architectural envelope — and occupancy type — establishes the demand for energy inputs to maintain thermal and visual comfort, functionality, etc., and based on this relationship, the architect is responsible for creating either a low or high demand for energy. For example, if a building is overglazed, it will need a larger (year-round) energy input to maintain thermal comfort than a building more attuned with its microclimate.

By investing in the thermal envelope upfront, downwind savings of reduced mechanical systems can be achieved, which are less costly to operate and maintain and which even weigh less and have reduced impact upon the overall buildings’ aesthetics. Additionally, through the use of parametric analysis, by leveraging a truly integrative design process, teams can work backwards from the end-goals (i.e. zero-energy, LEED Platinum, etc.) to identify (with pricing) "bundles" of strategies that meet the desired goals and are affordable early in design. These early options would serve as design guidelines, allowing performance (and data) to influence the architecture, rather than the other way around. By prioritizing glazing ratios, better glazing performance, better envelope performance, and eliminating thermal bridging, "Architecture" wins by serving as a prominent system, rather than being placed on life support. Shouldn’t this be where the primary investment occurs? The envelope is the part of the building on permanent public view, and it is composed of the elements which last the longest. Cities are already adopting policies dictating window-to-wall ratios, envelope performances exceeding ASHRAE 90.1 and commissioning/thermal bridging elimination, and it is a game changer for emissions reductions and aesthetics, as we move away from ubiquitous glass boxes towards refined facades that are human-scaled and climate-specific.

building wall insulation 

Photo Courtesy of Stantec

Example of an enhanced thermal envelope under construction for a net-positive energy building, which seals all potential leaks and reduces thermal bridging

Prescriptive Codes

Campuses should establish their own specific guidelines so projects can adhere to the overall goals of the campus meaningfully. Proposals generated for design services would be outcome-specific and less open-ended, resulting in individual projects understanding how they play a role in the larger campus efforts — not just the new construction projects. While similar to campuses requiring LEED certifiability, this is a greater level of specificity, specifically for materiality and energy demand, that can benefit building performance, reduce operating costs, boost the market for better products and even generate higher (more valuable) skilled labor locally, as campuses can be large enough to generate their own local spheres of economic influence.

The City of Boston is doing this by leveraging their Article 37 process, which since 2007, requires projects >100,000gsf to demonstrate LEED certifiability. Over the years, its scope has expanded to include provisions for resiliency and smart utilities, MA Stretch Energy codes (>10 percent energy reduction above ASHRAE 90.1) and in April of 2019, the Boston Planning & Development Agency (BPDA) launched the Zero Carbon Assessment tool to help construction beginning in 2020 meet their goal of zero emissions by 2050. All projects under Article 37 are obliged to model 1) a code-compliant baseline, 2) a MA Stretch Energy code-compliant baseline and 3) the proposed project. The Zero Carbon Assessment adds an additional modeling run early in design, with pricing, which is essentially 100 percent electric, Passive House equivalency:

Required:

  • Continuous insulation: >R-50 roofs; >R-36 walls
  • Curtainwall: <U-0.05 opaque; <U-0.22; <SHGC-0.25 vision
  • Window-to-wall ratios: <40% commercial; <30% residential
  • Window assemblies: <0.22 commercial; <U-0.15 residential
  • ACH50 = <0.06 air tightness
  • Heating/cooling systems: high efficiency, use optimized
  • DOAS with ERV >80% efficiency and MERV8 filters, or better
  • DHW: high efficiency with minimized pipe runs:
    • Residential – in-unit ASHP DHW
    • Commercial – central system
  • Energy Star appliances, induction cooktops/ovens and all LED lighting with controls

Optional:

  • Onsite PV – amount optional, but must be investigated with some amount installed
  • GSHP – optional, but must be investigated

These guidelines are extremely useful, as the prescription removes the guesswork associated with achieving high performance. Teams can begin project discovery and development by identifying "bundles" of strategies that meet these measures, with pricing. While Boston-centric, guidelines elsewhere would need to be adapted accordingly.

Beyond efficiency, there are many additional benefits. Better envelopes increase resiliency through increased durability, noise reduction and increased thermal comfort. Better thermal performance means that students/faculty/staff can shelter in place for longer periods of time during disruption more comfortably, and this, with noise reduction, are also important evidence-based benefits that improve mental acuity for better sleep on campus, better academic performance in the classrooms, etc.

Existing Buildings

While these guidelines would apply to both new and existing buildings, additional care needs to be given to existing buildings, particularly, to ensure enclosure improvements do not create moisture issues within the envelope. Software analysis, i.e. WUFI, allows designers to perform hygrothermal analysis of proposed assemblies to manage dew point locations. Additionally, for existing buildings, regardless of whether under full renovation or phased improvements, upgrades can be phased-in over time to align with capital planning schedules. This allows campuses the next thirty years to upgrade their existing building stock to meet the prescriptive measures, although most of the work needs to take place by 2030 if campuses are to do their part in meeting the Paris Agreement. Lastly, for historically sensitive projects, where the prescriptive measures would not be appropriate, these projects will have to rely on minor phasing out of systems, systems upgrades and emissions tracking and offsetting via onsite/off-site renewables.

Conclusion

We are seeing a shift towards performance-based buildings. This does not mean that LEED will disappear; it means that energy and emissions will drive decision-making, while LEED rounds out a holistic framework for green space, water, materials, transportation, etc. Campuses can achieve zero emissions and are already working towards this goal. They will likely arrive before cities and countries, providing valuable insight into scalable solutions. While waste, transit and behavior change are essential, all-electric buildings running on a renewables-based smart grid will be the deciding factor regarding zero emissions. Campuses can do this by creating site- and climate-specific guidelines for renovation and new construction projects, through onsite and offsite renewables, and through soliciting service providers with the commitment and abilities to meet these goals through true integrative design. Too often, "sustainability" is more an outcome tweaks to "business as usual," with the primary focus on "design." By establishing clear, measurable expectations, all projects can fit into greater campus objectives, both at the Presidents’ levels and that of their Project Managers, who designers interface with the most. This is an exciting time for our industry, as well as working in higher ed, with efforts invested influencing the societal shift towards a post-carbon economy!

This article originally appeared in the March/April 2020 issue of Spaces4Learning.

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