Chapter 4
New Buildings
Vancouver, British Columbia, is wedged on the west coast of Canada between the ocean and the mountains. It is sometimes thought by Canadians to be a bit like California – a place that moves to its own rhythms – occasionally called “the left coast” by some. As such, it often has been a source of innovation, as it is in forging techniques to build dramatically better buildings. In 2011, the University of British Columbia opened the Centre for Interactive Research on Sustainability, a net-positive building – actually helping draw down carbon emissions. Designed as a living laboratory, the building is also an educational project for students in engineering and architecture. It has anticipated an ongoing necessity for improvement and has provided an excellent way to assist in widely disseminating best practices about new building construction to the industry in British Columbia.
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Downtown Vancouver is built on a peninsula. It’s a beautiful piece of land, and long ago a farsighted decision was taken to protect the western-most end of that peninsula as a park – Stanley Park. It is surrounded by nearly ten kilometers (about six miles) of seawall, and it is possible to run, walk, or bike around the seawall. In doing so, the views are incredible – of snow-capped mountains behind North Vancouver; of the busy harbor; of the magnificent Lions Gate Bridge, which opened the north shore of Vancouver (the “British Properties”) to development; of Siwash Rock mysteriously erect a few yards into the ocean; of ships moored waiting for cargo; of the beaches of English Bay; and then of downtown. When I run the seawall, I usually run clockwise, starting in English Bay and moving west and north. Running in that direction, when you come around the last corner of the park, the glory of downtown Vancouver opens up in front of you – the convention center with its sails and green roof and an array of new buildings, as far as you can see.
At least since the world’s fair took place in Vancouver in 1986, the city has had a building boom downtown and in the adjacent neighborhood of False Creek. The number and scale of the buildings is significant – and illuminates a fundamental point about work to address climate change in cities. In cities such as Vancouver (and those in China), where there is significant construction and a modern building boom, how do we ensure that our newly constructed buildings are built in a way that secures a low-carbon future? The answer lies in the actions of city governments.
Planning Approvals and Building Codes
Central to the role of almost every city government is the task of guiding development – planning where new buildings should be; what uses are appropriate in different neighborhoods; and the size, height, and density of a proposed building. In different countries there are different rules, but such rule making is typically undertaken through planning approvals and a citywide development (or “Official”) plan. It might say, for example, that tall skyscrapers in a downtown core are welcome, but that abattoirs in a residential neighborhood are not; or that owners of single-family homes may convert their houses into duplexes, but that the building must still be about the same size as other houses in the neighborhood.
We can see the beauty of a modern building from many angles. But what matters from a climate-change perspective is often harder to see. Is the building insulated properly? Can it generate its own energy? Does it use its design to minimize the need for heating and cooling? Does the beautiful glass exterior hide an inefficient building that better design would have made energy efficient? Source: David East/Unsplash.
In many places, cities also control the building code – the rules that govern construction of new buildings. The twin tools of planning approval and approval over the methods of construction are powerful, as a city can then influence both the density of a city and how easy it is, for example, to travel between home and work or school, as well as the actual quality of construction. These powers have important environmental impacts – impacts that become critical in the growing cities of China (and soon Africa and India), where new buildings can make or break a long-term climate-action plan. They can be built to conventional standards that use carbon-intensive materials and lock the building in to high operational-energy needs that will be hard to address later. Alternatively, they can be thoughtfully designed to use carbon-storing materials and generate zero emissions during their operation.
It is possible today to mandate that new buildings be designed to fit the latter criteria: to be energy efficient, to use less carbon-intensive materials, to use technologies that generate little or no emissions, and to adopt new passive-energy strategies (passive energy is also a very old-fashioned idea). When these measures are done well, to the highest of modern standards, a new building can be part of the climate solution rather than part of the problem: buildings can be a net carbon sink. Before discussing the leading examples of how cities are making this happen, it is useful to understand some facts about constructing new energy-efficient buildings.
Green Operating Building Standards
Constructing a new building to use very little energy to operate is much easier than retrofitting an existing building to the same standards. Indeed, it is now possible to design new buildings to produce as much renewable energy as they use over the course of a year: these are usually called net-zero-energy buildings. Buildings can also be constructed to generate no net emissions in operation: these are called net-zero-emission buildings, or zero-carbon buildings. Since buildings last for decades, it is critical that the buildings we put up now not lock us in to continued emissions that may be difficult to reduce or offset later. There are several green building standards that exist with different criteria – for example, the work done by Green Building Councils internationally. This chapter will explore what is currently possible and being undertaken in cities today.
Zero-carbon buildings operate using systems that generate no net emissions from the building operations. These buildings are often heated with electric heat pumps or with biogas-based district heating systems. The electricity supplied to these buildings must come from renewable-energy sources, either on- or off-site. As we saw in Chapter 2, many utilities now offer contracts for electricity generated from renewable sources.
Net-Zero-Carbon Buildings
By definition, net-zero-carbon buildings must be designed to use as little energy as possible in their operations. That means designing buildings with effective insulation, an airtight building envelope, and high-performance windows. It also means using high-efficiency equipment and giving careful attention to how the occupants will use energy.
Fortunately, energy-efficient options exist for many building components. The field of building science has exploded in recent years, as demand grows for energy-efficient, healthy buildings. Zero-carbon buildings can now be designed and built with greater ease and less cost.
Does building to high energy efficiency cost more? Yes. Typically, the cost of construction will be higher. Nonetheless, the cost of operation will certainly be lower. There are multiple reasons builders generally have not built to the highest technically possible building standards – the single biggest is that the costs of construction are paid by the constructor of the building, but the operating savings accrue to the future owners or to the tenants of the buildings. The problem of such split incentives means that regulatory intervention is critical to correct the market failure. However, as architects, construction workers, and suppliers gain knowledge and experience the added cost of building to high energy-efficiency standards is decreasing. But even if it were not, today any extra construction costs are paid back relatively quickly through operating savings – and those savings continue for the rest of the building’s life.
The split-incentive problem does not apply to institutions or businesses that build anticipating that they will own the building for its lifespan. Thus we often see governments further ahead in energy efficiency in new construction than the private sector, as the cost incentives – lower lifetime cost, including the cost of operations – are aligned with energy efficiency. A nice example is in Cambridge, Massachusetts, which in addition to doing interesting work with a consortium of local businesses and institutions on a collective approach to net-zero buildings, recently opened the King Open and Cambridge Street Upper Schools Campus.
The campus includes two schools, offices, a public library, a community center, and other amenities. Using advanced energy efficiency, solar energy, geothermal heating, and a rainwater-reclamation system, the project is close to net zero – and will become net zero as the local energy grid becomes cleaner.
New Technologies
Technologies are also evolving. Electric heat pumps capable of reaching average efficiencies of 300 per cent and more are now available. It is difficult for a non-engineer like me to understand how 300 per cent efficiency is possible, but it’s due to the nature of heat pumps. Heat pumps move heat rather than generating it and are therefore capable of greater than 100 per cent efficiency. Even in cold Canadian winters, heat pumps can extract heat energy from the outside and use it to keep a building warm. And in summer, they move heat out of the building, replacing the need for a separate air conditioner.
There are improved designs to many aspects of a building – windows, insulation, lighting, control systems – but one relatively new technology that has captured attention is using heat pumps to extract energy from wastewater and sewage. The technology is relatively simple and has been piloted in a number of cities, including Vancouver, and Galashiels and Glasgow, Scotland. Its virtue is that it turns waste into a useable product – heat – simply and inexpensively, and moreover uses heat sources (wastewater and sewage waste) that have not been traditionally thought of as a resource, which exist in all buildings, and are renewable.
Modern Passive Design
New technology is not the only solution. There are many building techniques that use cheap and easy passive-design principles to reduce the need for energy-based systems. The South African cities of Cape Town, Durban, Johannesburg, and Tshwane have all committed to using passive-design standards to ensure that all new buildings are zero carbon by 2030.
Buildings form a significant share of emissions for these South African cities, and energy use for air conditioning in their hot climate is a major consideration, particularly as the South African energy grid depends to a significant proportion on coal. South Africa also struggles with high unemployment and very high poverty rates, as well as with one of the world’s worst levels of income inequality. Building to tough green standards is often perceived as expensive and only for those who can afford it. Consequently, the four South African cities are investing heavily in stakeholder engagement and education and awareness campaigns, in addition to finding affordable solutions. Their energy-efficient building strategies place a huge emphasis on passive-design principles (some of which are described below). These techniques are generally cheap and easy and can be used anywhere.
Color matters to passive design. In the same way that a sidewalk can get very hot on sweltering summer days, dark surfaces on buildings will absorb more heat than light-colored ones. This is true of all surfaces, and significant work has been done to create cool roofs – by designing roofs to reflect the sun’s rays. Many different cool-roof materials are now available, from asphalt shingles to steel roofs to spray-foam flat roofs to white-painted roofs, and more. Cool roofs don’t even need to be white: highly reflective darker cool-roof materials are available. And while cool roofs reduce the need for air conditioning in the summer months, they do not have a negative effect on the need for heat in the winter. Green roofs, designed to use rainwater and sunlight to feed plants, are also a passive way of keeping a building cool in summer while absorbing heat through transpiration and storing carbon in plants, and in the right locations can function as an above-ground private or public park.
It is also possible to use the siting and orientation of a building to control heat accumulation from the sun and create more comfortable buildings, an approach used in ancient times as well as more recently. The idea is enjoying renewed interest and adoption in South Africa and elsewhere. “Solar gain” comes from direct exposure to the sun’s rays. The sun moves from east to west and passes high in the sky in the summer months. In winter, the sun arcs closer to the southern horizon in the northern hemisphere and closer to the northern horizon in the southern hemisphere. Careful orientation of a building and siting of the windows can substantially reduce passive heat gain and the need for air conditioning in the summer. That same orientation can maximize passive heat gain in the winter. This measure costs next to nothing to implement but generally fell out of favor in the post-war building boom of the 1950s and 60s at a time of cheap energy. Furthermore, the use of overhangs, louvers, blinds, plants, and other window-shading features can also help to control solar-heat gain. Finally, careful window placement can be used to reduce the need for electric lighting with its associated waste heat. Creating comfort for building occupants can mean designing better buildings, and in the process using far less energy.
I recently visited an interesting building in Waterloo, Ontario, that is well on its way to being a certified zero-carbon building. It is a three-story office building with solar panels over the parking lot, a ground-source heat pump, a grey-water system, and a very nice green wall. But the feature that impressed me the most is one that’s hard to see: the solar wall. It looks like a normal dark metal siding on the south side of the building. There are small holes drilled into the siding and behind it is an air-filled cavity. Air enters through the holes and is warmed when the sun hits the dark metal. That warm air rises and is drawn into the heating system in winter. The heating system therefore uses far less energy to heat the building as the incoming fresh air is already pre-heated by the sun. On a sunny day last winter, when the outside temperature was −13°C (9°F), air entering the building through the solar wall hit 16°C (61°F). Twenty-nine degrees Celsius (52°F) of free heat on a cold winter day!
Finally, buildings can benefit from passive ventilation. Having windows that open and spaces that connect from one side of a building to another allow for cross-breezes that can do much to improve the comfort and air quality of a building. Warm air rises, and when openings are placed at the top and bottom of a building, the warm air escaping at the top can draw in cooler air at the bottom, a process often called the stack effect. This technique was used in the architecture of Ancient Iran to keep buildings cool.
These various possibilities illustrate that there are many considerations when designing new buildings for lower carbon emissions. Fascinating examples of city leadership on building standards demonstrate inspired action is possible – now.
Leadership that Works: Vancouver
Vancouver declared a climate emergency in April 2019 and directed city public servants to draft a strategy to address the emergency. The Climate Emergency Response report that followed outlined six “big moves” and fifty-three accelerated actions. Vancouver’s previous goal of reducing emissions by 80 per cent over 2007 levels by 2050, for example, was replaced with a greater (and scientifically required) ambition to become carbon-neutral by 2050. In the buildings sector, which in 2017 represented 59 per cent of the city’s total emissions, Vancouver has made significant progress, and its approach to new buildings is particularly noteworthy.
Vancouver is the most expensive place to buy a home in Canada. And with a growing population, demand for real estate is likely to remain high for quite some time. It is estimated that 40 per cent of the buildings that will exist in Vancouver in 2050 will be built after 2020, with the majority of this new development being residential (see Figure 4.1). To address the climate consequences of this building boom, Vancouver has pledged to have all new buildings be constructed to net-zero-carbon standards by 2030. In addition, Vancouver has committed to addressing embodied carbon (the carbon in building materials, such as concrete) as well: the city-council-approved goal is to reduce embodied carbon from new buildings and construction projects by 40 per cent below 2018 levels by 2030.
Figure 4.1: Vancouver’s Built Area by Building Type, 2020
Vancouver has a variety of building types – note the significant number of high-rise buildings (nearly 30 per cent). Source: Based on data from City of Vancouver, Zero Emissions Building Plan , July 2016.
Net-Zero-Carbon Building Strategy: Vancouver
In Vancouver, by 2015, greenhouse gas emissions from the operation of new single-family homes had been cut to half of 2007 levels through prescribed energy-efficiency measures. The targets for cuts to emissions from new buildings are set to increase incrementally until all new buildings are net zero carbon in their operations by 2030. Building bylaws support these reductions with performance targets for every major building type. These metrics measure annual greenhouse gas emissions, energy used for heating, and total energy used – all normalized to the size of the building.
The building standard that Vancouver favors (but does not mandate) for the residential sector is the Passive House standard. Structures built to this internationally recognized standard are so well insulated and airtight that their heating and cooling needs are minimal. Even in colder climates, most homes built to this standard could be heated by a heat output equivalent to that of a hair dryer. Small heat pumps connected to the ventilation system that brings in fresh air can easily meet all heating and cooling needs. This standard is supported by professional training programs, modeling software, and a third-party verification process. While Vancouver has not made achieving passive-house certification mandatory for all new detached houses, achieving very high standards of energy efficiency and zero emissions is required – and this standard will be the easiest method of achieving these targets.
Instead of using heat pumps, some homes may be able to use neighborhood renewable-energy systems. These district heat and cooling systems offer economies of scale for converting whole neighborhoods to 100 per cent renewable energy. They can use low-cost energy sources, such as waste heat from sewers and commercial or industrial centers or wood waste that is not contaminated with other materials like nails – known as “clean wood waste.” As Vancouver is a major exporter of lumber, the area is a great source of clean wood waste. These district energy systems are being expanded, and the proportion of energy they use from renewable sources is increasing.
Even with electrified heat systems, there are still emissions to consider. The electricity supplied to Vancouver is more than 97 per cent renewable, with most of the energy coming from hydroelectric dams. When electric heat and hot-water systems are used, buildings will be required to offset the small carbon footprint from electricity with onsite renewable energy systems or, if this is not feasible, by purchasing energy from other Vancouver-based renewable sources.
The shift to carbon-neutral buildings is supported by the center for excellence for zero emissions buildings, which shares information and best practices. It also helps suppliers of relevant building components (such as windows) and people in the building industry itself develop the skills necessary to expand capacity and to meet the zero-emission goal. Since the step-wise performance targets for buildings are known well in advance, suppliers, manufacturers, and the building industry are able to plan and build the capacity needed to meet future targets. The center also engages with the public to strengthen market demand for energy-efficient buildings.
Addressing Embodied Carbon
One of the many things that stands out in Vancouver’s plans is its attention to embodied carbon emissions. While efficiencies reduce the energy a building needs for its operations, concern remains about emissions associated with construction materials, which are part of a building’s carbon footprint. Currently more than half the lifetime emissions from an energy-efficient building may be emitted even before the doors open for the first time. Reducing these emissions is crucial to global efforts to limit warming from greenhouse gases. Since 2017, builders have been required to report embodied emissions in their projects. As reporting shifts to mandated reductions, bylaws and incentives are being developed to support the new design and building practices required.
Vancouver has been working with the construction industry, engineers, and other experts to devise realistic approaches to reducing embodied carbon, including the use of mass timber construction, lower-carbon concrete, and techniques to reduce the amount of concrete, steel, and aluminum needed. This continued experimentation and innovation is critical to show that it is possible – technically and economically – to reduce the embodied carbon in new buildings. Vancouver is leading the way.
A proposed thirty-three-story high-rise residential building was used as a model by City of Vancouver public servants for calculating embodied-carbon emissions. It allowed for a closer look at how embodied-carbon considerations might affect a building’s design. In the model, the calculated embodied carbon for building using standard materials was set as the baseline. The calculated effects of different design changes and material switches on embodied carbon were compared to this baseline. The goal was to achieve Vancouver’s climate target of a 40 per cent reduction in embodied carbon below 2018 levels by 2030.
Achieving a 40 per cent reduction in this case study required many measures, but the goal was attainable with current building techniques – no invention of new technologies or components was required. These measures included the use of low-carbon concrete, the replacement of carbon-intensive aluminum with steel, and either the use of precast hollow-core floor slabs or a 50 per cent reduction in underground parking. Combining all measures resulted in a modeled 47 per cent reduction in embodied-carbon emissions. Although a reduction in parking might require a change in municipal bylaws that, as in most cities, mandate a certain amount of parking for buildings, that too could work in Vancouver’s favor as it strives to create a more walkable city, with low emissions from transportation. That would be a significant positive synergy – but even if the building does not assist in that goal, the overall effect of the new rules is a building that, by using simple changes to design, generates far fewer emissions from construction.
Addressing embodied carbon is critically important to lowering overall emissions. As emissions from building operations decrease, the importance of emissions associated with building materials increases. The only emissions generated by zero-carbon buildings are those from their building materials. And once those buildings are built, those emissions are spent: we can do nothing to reduce them. The UN predicts that under a business-as-usual scenario, embodied carbon will represent 49 per cent of global emissions from buildings built between 2020 and 2050 (see Figure 4.2).
Figure 4.2: Total Carbon Emissions from Global New Construction, 2020–2050 – Business-as-Usual Projection
Source: Based on data from UN Environment, Global Status Report 2017 and EIA, International Energy Outlook 2017 .
Emissions from embodied carbon are not typically included in the carbon accounting for buildings. But if we are to achieve global emissions reductions sufficient to limit global temperature rise to safe levels, we cannot afford to ignore them. The accounting for embodied carbon contained in Vancouver’s climate-mitigation plan creates a useful precedent that will allow other cities to follow suit.
Best Practice Examples
There are significant examples of success when architects and engineers think creatively. Brock Commons Tallwood House is an eighteen-story residence at the University of British Columbia in Vancouver. Most of the residence’s structural features were built with engineered mass timber instead of concrete. Engineered mass timber uses layers of wood glued or fastened together to form prefabricated strong and stable joists, floors, and outer walls. Only the stairwells and main floor are made with concrete. Estimates put the embodied-carbon savings for the building over conventional construction at 2,432 metric tons of carbon dioxide: the equivalent to emissions from five hundred cars in a year. Tests showed that the residence meets all building-code requirements, including structural performance, fire prevention, and vibration levels. Not only is this the world’s tallest timber structure to date, but it has a very low embodied-carbon footprint, it cost less to build, and it was assembled in less than ten weeks.
New York City: New Buildings
New York City is expected to contain eighty thousand to one hundred thousand new buildings by 2050, a huge number. Achieving net zero emissions for the city by 2050 means that these buildings must be constructed to the highest feasible standards, or New York will not meet the goals that science suggests are necessary. To achieve these goals, the city is requiring that all new buildings be net zero carbon by 2030.
Green Building Codes
As noted above, cities differ in their ability to affect changes to building codes. The State of New York allows municipalities to adopt their own building and energy codes, so long as their standards are tougher than those set by the state. Consequently, in 2009, the City of New York began implementing its own building and energy codes.
Until recently, the New York City approach has been to incrementally increase the energy-efficiency requirements for new buildings based on national and international recommendations. These adjustments tended to consider parts of the building independently of the other parts and systems, and are easier to implement from both an industry and regulatory perspective, but possibly miss some benefits that a unified approach would provide. New York has been successful using this framework – for example, in 2016, NYC required air-leakage testing for all new buildings, giving a performance metric for how well the building is air sealed and pointing to where improvements can be made. Plans for future codes include increasing the required levels of insulation for residential buildings – a move projected to reduce total energy use by 25 per cent. These incremental improvements were successful in improving the quality of new buildings in New York, but the city has now recognized that a systemic approach is needed to achieve the energy efficiency required to make net zero carbon cost effective and accessible.
Buildings are far more than the sum of their parts. The energy performance of a building very much depends on how well different systems work together. A frame wall with four inches of insulation, for example, is interrupted every few feet by studs that conduct heat (or cold) past the insulation. If there is a vent going through that wall, from a kitchen fan for example, that vent will also conduct heat (or cold) past the insulation and may introduce leaks to the outside. The net effect is a wall that performs far less efficiently than you’d anticipate from the required four inches of insulation.
New York is therefore taking a new, whole-building approach to its building codes. It is looking at how the different systems work together: the insulation, the structure, the heating and cooling systems, the ventilation systems, the hot-water systems – everything that affects a building’s energy efficiency. Starting in 2019, the city is looking to phase in whole-building energy-performance standards, rather than using prescriptive standards that regulate each system independently. The result should be well-insulated buildings with minimal air leakage. These buildings will require relatively little energy to heat, cool, and ventilate, and will therefore require much smaller – and cheaper – heating and cooling systems. This reduces both construction and operational costs: requiring new buildings to be very energy efficient makes sense economically, socially, and climate-wise too.
These changes to the building codes used best practices from national and international organizations, and were developed from the input of thousands of stakeholders through meetings and engagement exercises. Urban Green, a nonprofit organization affiliated with the World Green Building Council, was set up in 2002 to help transform New York City buildings for a sustainable future, and they have been actively involved in engaging stakeholders and making recommendations to the city. A codes advisory committee is also being established to develop the whole-building energy-performance standards to be used in future building codes. Engaging stakeholders early means greater buy-in for changes over the long term.
Leading by Example – Again
During a transformation like this, a city government must demonstrate leadership in its own operations – both for credibility and as a way to show that the changes requested are technically and financially feasible. The City of New York has therefore been investing in significant improvements in the way public buildings are constructed and in reducing the energy use and carbon footprint of their new buildings. Since 2016, new municipal facilities have been required to be constructed so that they use no more than half the operational energy of buildings built to existing standards. This measure demonstrated that constructing buildings to high energy performance was possible and also helped architects, engineers, and tradespeople develop the knowledge and skills necessary for designing and constructing buildings to meet such standards.
In addition, New York City intends to source all electricity for municipal operations from clean sources. Being the biggest energy customer in the city, its demand for clean energy is likely to help transform the system, paving the way to greater installation and adoption of renewable energy by others.
The use of easily available renewable energy helps to expedite the transition to ensure that all new buildings in a city can be net zero carbon. There are currently several options for renewable energy in New York City. Green-power credits are available in the city and are based on electricity generated from renewable sources either within the city or from sources that feed directly into it. These are considered 100 per cent local renewable-energy sources. In addition, the city and the state provide incentives and tax breaks for installation of onsite solar power, and the city is planning to ensure widespread potential for the addition of solar systems to roofs.
This plan doesn’t just apply to large buildings. Single-family and semi-detached homes with solar potential are part of a program to require solar readiness. This may mean designing a roof for solar orientation and extra load capacity, installing the necessary wiring and meters for solar arrays, and strategically placing vents, pipes, and other roof-mounted utilities so they will not obstruct an added solar array. Once solar arrays become more affordable – or energy-performance targets get tougher – homeowners could easily add solar arrays to their homes. These buildings could then become net zero carbon.
The Kathleen Grimm School
The Kathleen Grimm School on Staten Island, which opened in 2015, is an inspiring example of how design thinking and use of space can make net zero carbon buildings possible. The school was designed as a pilot project to explore the feasibility of building a school to be net zero carbon (in a climate that has cold winters) and also net zero energy. This means that the school generates, on average, as much electricity from its onsite solar panels as it uses in a year for all its energy needs. The project stretched the imagination of architects, engineers, and even teachers and students.
The first challenge was to design the school to use vastly less energy than a typical school in New York City. This was necessary to ensure that the output from onsite solar panels could match the energy use of the school. Architects and engineers paid careful attention to the siting of the building, the pitch of the roof, the quantity of insulation, and the building’s airtightness. Geothermal heat pumps were used for heating and cooling. Special measures were introduced to minimize air leaks, including thirty-foot-tall precast concrete panels on the façade that were designed to curtail punctures to the structure when mounted. Lighting was another important design feature: careful placement of windows allowed classrooms to forgo the use of electric lights up to 90 per cent of the time, and in hallways 98 per cent of the light in daytime comes from windows.
Project-design meetings for the school included consultants, tradespeople, school administrators, faculty, and students – all could discuss how to save energy in every aspect of the school’s operation. Even the kitchen consultants found ways to slash energy use by using induction cookers and by rethinking meal planning. The outcome was a school designed to use half the energy of a typical New York City school.
To help create all the projected energy used to heat, cool, and operate the school, solar was chosen – requiring a huge number of solar panels. During the design process, concerns arose that even with solar panels on the roof, on its south-facing walls, and over its parking lot, the energy output of the solar panels would be insufficient to match the building’s needs. Accordingly, through a partnership with the Rensselaer Polytechnic Institute (an engineering university in New York State), the solar panels’ configuration was optimized to create a projected 35 per cent increased energy output. Thanks to the willingness of the school board, the architects, engineers, and others to try innovative approaches, a public school was built that will generate zero greenhouse gas emissions – all on a constrained municipal budget.
With time, lessons will be learned, expectations will change, and New York City’s buildings will become even more energy efficient. It’s exciting to think about how the city will look and feel with these carefully designed towers, offices, and homes.
What We See Today
Glass-façade buildings are common in large cities, particularly New York. Such buildings are popular since they are visually appealing, and they’re quick and cheap to build. But they’re not cheap to operate. Even high-performance glass is a poor insulator. Not only does this mean more energy is needed for heating and cooling, but it can also mean that both heating and cooling are required simultaneously in different parts of the building to keep temperatures stable on a cold, sunny day. This is very energy inefficient. While the new climate-action plan for New York City does not explicitly ban the construction of such buildings, it’s clear from the mayor’s words and from the performance requirements in the plan that these buildings will be very unlikely to be built in future – meaning that new skyscrapers are likely to look very different and be far more energy efficient.
“We are going to introduce legislation to ban the glass-and-steel skyscrapers that have contributed so much to global warming. They have no place in our city or on our Earth anymore ... If a company wants to build a big skyscraper, they can use a lot of glass if they do all the other things needed to reduce the emissions. But putting up monuments to themselves that harmed our Earth and threatened our future, that will no longer be allowed in New York City.”
– Bill de Blasio (New York City), 2019
The Final Word
As South Africa, New York City, and Vancouver have demonstrated, we have all the knowledge, technology, and other tools we need to build emission-free homes, high-rises, and commercial and other buildings. It’s often argued that we need to wait to reduce emissions, that it costs too much, or that we need to invent new technologies. It’s clear that emissions from buildings are a significant and critical part of emissions in cities – which, as we know, make up about 70 per cent of global emissions. It’s also clear that we have the technology today to build affordable buildings that generate zero or near-zero emissions – as we’ve seen with Tallwood House at UBC and the Kathleen Grimm School in New York. Programs such as Vancouver’s assist the construction industry in developing better materials, technologies, and techniques – all of which aid in the transformation we need. But that transformation doesn’t depend on those advanced technologies – it can be, and is being, done today. What it does depend on is political will. With that, in cities around the world, these steps can be duplicated if decision makers accept the value and viability of net-zero-carbon buildings with low embodied carbon – and people demand it. They can demand it with their voices, their votes – and their wallets. People choosing to buy energy-efficient buildings would ensure the market adapted rapidly, even in places where leadership from the city government is absent. Given the far lower costs of ownership, their wallets would benefit, too.