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168 169
Getting Beyond Energy:
Environmental Impacts, Building
Materials, and Climate Change
Stephanie Carlisle
The carbon record doesn’t lie. And what the record tells us is that emis-
sions are still rising: every year we release more greenhouse gasses
than the year before, the growth rate increasing from one decade to the
next — gasses that will trap heat for generations to come, creating a
world that is hotter, colder, wetter, thirstier, hungrier, angrier.
— Naomi Klein
Measurement is the first step that leads to control and eventually to
improvement. If you can’t measure something, you can’t understand it. If
you can’t understand it, you can’t control it. If you can’t control it, you can’t
improve it.
— H. James Harrington
Architecture in the Age of Climate Change
Architecture shapes the environment. Present assessments indicate that
buildings account for roughly 30 percent of global greenhouse gas emissions.1
It is further estimated that an amount equivalent to 60 percent of all existing
buildings will be built or rebuilt over the next two decades, making buildings
and infrastructure one of the most important causes of global climate change,
and one of the greatest opportunities for deep decarbonization.2 The next
decade is a critical window for global emissions reductions, and the effective-
ness and cost of mitigation may depend on the extent to which emissions are
dramatically curtailed in that time.3 Decisions that architects make today will
have immediate consequences and will bear fruit for decades to come — mak-
ing architecture vital to protecting the climate, natural resources, and the
health and well-being of communities around the planet.
As the dangers of climate change become ever more visible and undeniable,
architecture needs robust calculations of environmental impact in day-to-day
design practice. Undoubtedly, such quantification will add technical complexity
to an already challenging creative pursuit, but in fact the architect’s tool kit has
never been richer or better equipped for those who want to truly understand
the impact of buildings on the environment. The integration of architectural
design with a rigorous and scientifically grounded exploration of embodied
environmental impacts does not need to alienate the concerns, skills, and per-
spective of architects but instead can build on the strengths of design culture
and enrich design practice.
In the face of a fast-moving and imminent environmental crisis, the design
community cannot afford to be paralyzed by the seeming complexity of quan-
tifying architecture’s carbon and environmental footprint. The baseline for
responsible architecture practice has shifted, and we must learn to improve
carbon calculations as a matter of course, without questioning our identity as a
creative discipline. Much like the responsibilities of managing cost and adher-
The Lustron Houses were prefabricated, modular
homes built after World War II and designed to min-
imize or even altogether avoid any need for mainte-
nance or repainting.
1 Energy Information Administration, Emissions of Green-
house Gases in the United States 2009 (Washington, DC: US
Department of Energy, 2011), 22.
2 American Institute of Architects, “Why the Building
Sector?”AIA+2030 Online Series (2016), http: / / aiaplus2030.
org / why / ; James H. Williams, Benjamin Haley, Fredrich
Kahrl, and Jack Moore, Pathways to Deep Decarbonization
in the United States (US report of the Deep Decarbonization
Pathways Project of the Sustainable Development Solutions
Network and the Institute for Sustainable Development and
International Relations, revision with technical supplement,
Nov. 16, 2015).
3 Intergovernmental Panel on Climate Change, Climate
Change 2014: Synthesis Report: Contribution of Working
Groups I, II and III to the Fifth Assessment Report of the Inter-
governmental Panel on Climate Change, ed. R.K. Pachauri
and L.A. Meyer (Geneva: Intergovernmental Panel on
Climate Change, 2014), 25.
Getting Beyond Energy: Environmental Impacts, Building Materials, and Climate Change
170 171
ing to structural principles, the act of calculating environmental impact can
become the basis for an innovative and ethical design practice. If architects
want to maintain agency over the built environment, there is responsibility that
comes with that power.
Energy Is Not an Environmental Impact
Within the study of sustainability, there is a recognition that reductions in ener-
gy consumption will not be enough to counter global climate change and that
the impact of buildings, construction, and infrastructure extends far beyond
the fuels combusted or consumed within a building.
For decades, architects and engineers have used embodied energy as a stand-
in for resource consumption and environmental impact, extending the domain
of architecture over larger systems of global production and manufacturing.4
Conceptually, this premise is essential for understanding the impact of con-
struction more fully. However, the practicality of our reliance on energy as
a broad measure of environmental impacts is less clear. In the face of that
uncertainty, architects and engineers still turn to the primary flow that they
have historically tracked and to a unit, the megajoule, that has been used for
decades as a measure of efficiency and performance. But if the megajoule is
not the best indicator of environmental impact, then traditional energy models
will be inadequate for gauging architecture’s relationship to climate change.
Many architects, engineers, and researchers feel conflicted about the resur-
gence of embodied energy in contemporary architecture discourse, whether it
is used as a metaphor or as a literal modeling practice. This hesitation is not
born out of a lack of concern for ecological or social questions: the reality of
climate change and its implications for design and construction of the built
environment are profound. Indeed, such thinking crops up in any number of
design questions, such as: What is the relationship between energy efficien-
cy measures and carbon emissions? Does it make sense to super-insulate a
building in a region with a low-carbon energy grid? What are the trade-offs
between durable industrial products and bio-based materials? How can the
value of building reuse be better articulated and quantified? Where can the
biggest contributions be made?
Unfortunately, none of these questions can be sufficiently answered by only
calculating embodied energy. The problem is that energy consumption is simply
not equivalent to environmental impact. Embodied energy is a proxy, like trans-
portation distance or recycled content — a stand-in for a host of relationships
and end-point measures that are much more complex and meaningful. Clearly,
all megajoules are not created equally.
While some environmental impacts are closely tied to fossil fuel combustion
and carbon emissions, reducing the richness of material flows and mecha-
nisms of environmental impact into a single unit is overly simplistic. Energy is
not just an ability to do work or a fuel stock combusted to produce electricity
and heat. Energy sources have context. From an environmental and an eco-
nomic perspective, it matters a great deal how energy resources are extracted,
transported, generated, and consumed.
For example, the environmental impact of fossil fuel consumption is not fully
captured by its global warming potential. Land use transformation, habitat
loss, and water pollution are difficult to quantify and often hidden from sight,
but they are no less meaningful than carbon emissions. The effects of coal
extraction through mountaintop removal in Appalachia or strip mining in
Australia are not fully described by a calculation of the emissions released at
a power plant. Deforestation, soil erosion, habitat destruction, disturbance to
groundwater levels from pumping operations, disposal of overburden, heavy
metal contamination from acid mine drainage, and long-term health issues
suffered by nearby communities all extend the scale, scope, and nature of dis-
turbance far beyond direct CO2 emissions.5 [FIG. 1]
Climate change can even be worsened without any combustion at all.
Presently, the Intergovernmental Panel on Climate Change estimates that
roughly 15 percent of all carbon emissions are attributed to land use
transformation — be it the conversion of wetlands and forests into cities or
agricultural land.6 Architects may be accustomed to specifying wood certi-
fied by the Forest Stewardship Council, but they may not have considered the
implications of increased cultivation of soybeans for bioplastics, resins, foams,
and biofuels.
Energy or carbon assessments alone cannot capture the trade-offs implicit
in the very technology supporting energy transformation. The same solar
cells, wind turbines, and high-efficiency mechanical, electrical, and plumbing
systems that enable the industry to move toward “net-zero” buildings also
support the extraction and processing of rare earth metals. Such processes
Fig. 1 While burning coal releases large quantities
of CO2, coal mining has a much broader environ-
mental impact that is often difficult to measure.
1
4 Emmanuel M. Rohinton and Keith Baker, Carbon Manage-
ment in the Built Environment (London: Routledge, 2012), 145.
5 US Environmental Protection Agency, The Effects of
Mountaintop Mines and Valley Fills on Aquatic Ecosys-
tems of the Central Appalachian Coalfields (2011 Final),
EPA / 600 / R-09 / 138F (Washington, DC: EPA, 2011); Pamela
Spath, M.K. Mann, and Dawn Kerr, Life Cycle Assessment of
Coal-Fired Power Production (Colorado: National Renewable
Energy Laboratory, 1999).
6 Pete Smith et al., “Agriculture, Forestry and Other Land
Use (AFOLU),” in Climate Change 2014: Mitigation of Climate
Change, Working Group III Contribution to the Fifth IPCC
Assessment Report, ed. Ottmar Edenhofer et al. (Cambridge:
Cambridge University Press, 2014).
Getting Beyond Energy: Environmental Impacts, Building Materials, and Climate Change
172 173
are not abstractly impactful or an allusion to the complexity of globalization.
There is a direct relationship between the policy, design, and industry that link
a green office building in Seattle to the toxic sludge filling Baotou Lake — the
site of the Baogang Steel and Rare Earth complex, a leading global supplier of
the dysprosium used in batteries and wind turbines, as well as the tellurium
used to produce inexpensive and efficient solar panels. While architects strive
to create greener and less impactful building projects, they are also transitive-
ly shaping these distant landscapes.
Tracking Impacts across Space and Time
For better or worse, the scale of buildings and construction extends far
beyond the building site and the depth of environmental impacts stretches far
beyond carbon emissions. Understanding architects and engineers’ power to
shape both the built and natural environment demands that the building and
construction industry become far more sophisticated and acknowledge that
material and design decisions extend far beyond what has traditionally been
defined as the scope and scale of design practice.
Every project that is built carries environmental burdens for terrestrial,
aquatic, and atmospheric systems. Design decisions and material choices are
inextricably linked to landscapes of extraction, production, manufacturing,
and eventual disposal. In order to dig into the complexity of the production,
consumption, and disposal of building materials, architects must consider the
flows of materials and energy across their full life cycles.
When an engineer is refining a structural concept or specifying steel members,
her decisions may have a direct impact on the air quality in Tangshan, the larg-
est steel-manufacturing city in China. The environmental impact associated
with that steel production is not felt by building occupants, but the 5.5 million
people around the world who die prematurely every year from breathing pol-
luted air are very real. But if not steel, then what? Cement production makes
up nearly 5 percent of global carbon emissions, a number slated to rise pre-
cipitously in coming decades.7 Commercial forestry carries landscape impacts
as well but also provides an ecosystem service in the form of biogenic carbon
sequestration.
In truth, material evaluation and comparison in design is never as simple
as substitution or selection. How can so much information be managed
without a clear model and method? How do we keep the multitude of impacts
in mind as we expand the complexity and nuance of design? If architects
cannot describe or measure the full impacts of buildings, how can they reduce
them?
Life Cycle Assessment and Environmental Impact
While embodied energy hides such interconnections within a single unit,
there is an alternate framework that allows for a systems-based approach to
measuring and describing environmental impact. In use for more than three
decades, life cycle assessment (LCA) is a quantitative methodology that tracks
the material, chemical, and energetic flows in a product system over its full life
cycle, connecting the inventory of materials and processes to their impacts on
aquatic, terrestrial, atmospheric, and human systems.
LCA models draw from international, peer-reviewed databases of materials
and processes that translate inventory data (material and energetic inputs
and outputs) into natural resource, environmental, and human health impacts
across a number of standardized categories, such as global warming potential
(GWP), ozone depletion, acidification, and eutrophication.8 The results allow
designers to trace the discrete environmental impacts of specific materials
and processes through each life cycle stage: material extraction, manufac-
turing, transportation, construction, use, and end-of-life, including demolition,
disposal, and recycling.9
The collection of inventory data and the characterization of environmental
impacts is not the work of architects but rather a collective enterprise of
chemists, engineers, ecologists, biologists, climate scientists, toxicologists,
and industry — a body of knowledge that is constantly improving in quality,
scale, and scope.
LCA provides an analytical framework to model complex product systems,
identify environmental impacts, and improve manufacturing and construction
processes.10 LCA was initially developed as a tool for incremental improve-
ment, supporting design iteration with a direct link between materials or pro-
cesses and the environmental impacts that they may produce. LCA practice
has developed significantly since the first multi-criteria model was built in the
late 1970s to evaluate trade-offs between energy, water, and material resource
consumption and pollution from glass and plastic bottles.11 In the last thirty
years, the method has been used to evaluate the full life cycle of environmen-
tal impacts for sophisticated products and services such as consumer elec-
tronics, biofuels, textiles, and agricultural production.
Still, a building is not just a difficult product. A building is a complex and
dynamic system with hundreds of materials and processes coming together
not just at the point of construction but continuously, in bits and starts, over
its full life cycle. While structural materials will likely remain in place for the
full life of a building, coatings, finishes, equipment, and hardware are periodi-
cally replaced. Roofing assemblies outlive their useable life and are repaired
or replaced; cladding is upgraded as performance or aesthetic sensibilities
change. Some building types — like commercial office buildings — may be
reconfigured with a new fit-out every five to ten years, sending thousands of
pounds of gypsum, flooring, plastics, and sheet metal to the scrapyard or the
landfill. Life cycle assessment provides an ordering framework for this com-
plexity — allowing materials to be placed in context and in time.
There are three main challenges to conducting life cycle assessments of whole
buildings and architectural assemblies: inventory, resolution, and iteration.
In the past five years, significant progress has been made in the development
of tools and databases that support architects in conducting LCA during the
design process, addressing all three of these challenges.12 Inventory, the col-
lection of discrete material quantities, is greatly improved through tools such
as Tally, a plug-in for Revit that makes use of building information modeling
(BIM) workflows that support simultaneous design development, documenta-
tion, and analysis — allowing for greater collaboration among team members
from various disciplines and skill sets. A conceptual shift from discrete, scaled
drawings to multifunctional and collaborative modeling allows for even sche-
matic designs to carry intelligence and nuance, connecting design intent with
7 Manfred Fischedick et al., “Industry” in Edenhofer et al.,
Climate Change 2014, 739; Global Carbon Project, Global
Carbon Budget: Data (2016), www.globalcarbonproject.
org / carbonbudget / 16 / data.htm; Ecofys and ASN Bank,
World GHG Emissions Flow Chart 2010 (2013), www.ecofys.
com / files / files / asn-ecofys-2013-world-ghg-emissions-
flow-chart-2010.pdf.
8 ISO 14040:2006 and ISO 14044:2006, Environmental Man-
agement: Life Cycle Assessment: Principles and Framework
(International Organization for Standards, 2006).
9 R.H. Crawford, Life Cycle Assessment in the Built Environ-
ment (London: Spon Press, 2011).
10 Kathrina Simonen, Pocket Architecture: Life Cycle
Assessment (London: Routledge, 2014).
11 Henrikke Baumann and Anne-Marie Tillman, The Hitch
Hiker’s Guide to LCA: An Orientation in Life Cycle Assessment
Methodology and Application (Sweden: Studentlitteratur AB,
2004).
12 Roderick Bates, “Life Cycle Assessment at the Speed of
Design,” Building Energy 35, no. 2 (2016): 44–46.
Getting Beyond Energy: Environmental Impacts, Building Materials, and Climate Change
174 175
technical data. Such integrated workfl ows allow for LCA to be conducted by
designers as an integrated and iterative practice, with LCA models gaining
resolution natively as building design progresses.
At the same time, the building material databases underlying tools such as
Tally, Quartz, and Athena have become more robust and represent a fuller
spectrum of architectural materials and techniques. Developed expressly
for use by architects and engineers, LCA tools nest individual materials into
nuanced assemblies that allow designers to compare results for hundreds of
concrete mixes, glazing assemblies, cladding options, or waterproofi ng sys-
tems — rather than merely comparing simple materials like concrete, steel,
wood, or cement. New tools presently in development aim to make the practice
even more accessible and balance the ease of modeling with the resolution of
results. [FIG. 2]
Quantifying and tracking all of the material fl ows across a building’s full life
is a daunting and complicated task. But architects revel in complexity. The
contemporary narrative of the discipline assigns value according to architects’
ability to manage complexity and open-endedness in a practice that demands
both technical acuity and artistic vision. So what explains the resistance from
both academia and practice to the modeling and quantifi cation of environmen-
tal impact?
Has climate change shaken our confi dence? Or is our love of complexity
reserved only for geometry, cultural context, economics, logistics, and semi-
otics? Are architects waiting for a more prescriptive approach to lowering
embodied carbon? The practice of life cycle assessment has been around for
three decades; still, architects struggle with assessing the environmental
impacts of their projects — whether the embodied impacts of building materi-
als or the global warming potential of operational energy. A common explana-
tion offered by academics, policy makers, and sustainability-minded architects
is that LCA is simply too complicated, too time-consuming, and too intimidating
to be embraced widely, despite the presence of tools and technology available
to facilitate it.13 Surveys of practitioners also point to the lack of demand from
clients as a key barrier to use of LCA.
While we are far from a reality in which every architecture offi ce engages
in iterative energy modeling, the conversation surrounding evaluation and
prediction of operational energy has a different tone. Is this because kilo-
watt-hours are more easily converted to cost, a unit that building owners feel
deeply invested in? Is it simply that energy is a far more tangible and quan-
tifi able fl ow? Is it because calculating energy consumption has long been
required of architects and is enshrined in building code?
When asked to make the jump from energy to carbon — from cost to environ-
mental impacts — does our collective hesitation refl ect a subconscious suspi-
cion of the science of climate change? Does it refl ect a collective guilt over the
magnitude of carbon emissions tied to the concrete, metals, and plastics used
on each and every project? Or does carbon accounting seem like one more
concern among many, a distraction from design? These are emissions that we
cannot even bring ourselves to properly calculate, let alone reduce or offset.
11 kg CO
2
-382 kg CO
2
Electricity,
24.9 kg CO
2
-22.4 kg CO
2
Synthetic
rubber
58.8 CO
2
Zinc
12.1 kg CO
2
34.2 kg CO
2
Heat, district
or industrial
13.4 kg CO
2
Aluminium,
wrought
790 kg CO
2
Aluminium,
wrought
311 kg CO
2
Synthetic
rubber
60.8 kg CO
2
18.1 kg CO
2
Zinc,
primary
11.8 kg CO
2
16 kg CO
2
Electricity,
voltage
25.1 kg CO
2
-22.4 kg CO
2
Aluminium,
wrought
443 kg CO
2
Nylon 6-6,
glass-filled
52.7 kg CO
2
Section bar
extrusion
53.2 kg CO
2
15.9 kg CO
2
Anodising,
aluminium
72.9 kg CO
2
Carbon
black
Carbon
black
18.5 kg CO
2
Aluminium,
primary,
-36.3 kg CO
2
-380 kg CO
2
Electricity,
medium
voltage
Electricity,
medium
voltage
medium
voltage
Electricity,
medium
voltage
Electricity,
medium
voltage
Electricity,
medium
voltage
25 kg CO
2
-22.5 kg CO
2
16.8 kg CO
2
Glass fibre
reinforced
Glass fibre
reinforced
65.1 kg CO
2
Heat, district
or industrial
18.5 kg CO
2
-41.2 kg CO
2
Anodising,
aluminium
65.4 kg CO
2
63.8 kg CO
2
Aluminium,
wrought alloy
27.8 kg CO
2
Nylon 6-6,
glass-filled
53.5 kg CO
2
Section bar
extrusion
53.2 kg CO
2
Waste
rubber
58.2 kg CO
2
Municipal
solid waste
74.3 kg CO
2
Aluminium
waste
-792 kg CO
2
Aluminium
framing,
initial
741 kg CO
2
Aluminium
framing,
replacement
244 kg CO
2
Aluminium
hardware,
replacement
22.9 kg CO
2
Weather
Sealing
replacement
45.3 kg CO
2
Aluminium
framing
1.05E3 kg CO
2
Aluminium
338 kg CO2
window
frame
C&D Waste
scenario
-716 kg CO
2
Curbside
collection
75.7 kg CO
2
24.6 kg CO
2
Waste
plastic
14.6 kg CO
2
Poly-
high density
high
Electricity,
voltage
high
Electricity,
voltage
high
liquid
Aluminium,
primary,
liquid
Aluminium,
primary,
ingot
Aluminium,
primary,
ingot
Aluminium,
scrap,
post-
consumer
Aluminium,
scrap,
post-
consumer
ethylene,
IMPACT
CREDIT
(RECYCLING)
ASSEMBLY
PROCESSING
MATERIAL
ENERGY
WASTE TREATMENT
DISPOSAL SCENARIO
MARKET
(INCLUDES TRANSPORTATION)
KEY
kg CO2 eq
material/
process
2Fig. 2 Even small construction elements — such as
aluminum window frames — are composed of a large
number of parts, each embodying signifi cant carbon
emissions.
13 Maureen A. Olinzock, Amy E. Landis, Christi L. Saunders,
William O. Collinge, Alex K. Jones, Laura A. Schaefer, and
Melissa M. Bilec, “Life Cycle Assessment Use in the North
American Building Community: Summary of Findings from
a 2011 / 2012 Survey,” International Journal of Life Cycle
Assessment 20, no. 3 (2015): 318–31; Joyce Smith Cooper and
James A. Fava, “Life Cycle Assessment Practitioner Survey:
Summary of Results,” Journal of Industrial Ecology 10, no. 4
(2006): 12–14.
Getting Beyond Energy: Environmental Impacts, Building Materials, and Climate Change
176 177
3
4
Figs. 3–7 Tally is a plugin for Revit that allows
designers to measure the environmental impacts of
building, at the scale of an entire structure as well
as in order to compare individual design choices.
7
5
6
Getting Beyond Energy: Environmental Impacts, Building Materials, and Climate Change
178 179
Life Cycle Assessment as a Creative Practice
Instead of sidestepping environmental modeling, architects should take
advantage of the newly available power and integration provided by LCA-en-
abled tools to expand their design agency. In order to fully embrace these
possibilities, architects will also need to tap into their imaginative potential
and see environmental modeling as more than just a way to make buildings
less bad. When life cycle assessments are billed as sustainability metrics or as
a means to secure LEED points, architects miss the creative potential of such
investigations.
While LCA is a practice based on hard science, it also supports deep thinking
about materials and places. Life cycle assessment provides architects with a
means and method to explore a richer narrative about the full history of mate-
rials — the mechanisms of their production as well as the landscapes of power,
labor, energy, extraction, and transformation that they perpetuate. A close
examination of materials does not limit design: it empowers and grounds cre-
ative practice.
Beyond simply supporting material selection, LCA equips designers to explore
the deep relationships that link landscapes of production, consumption, and
disposal. If LCA lends a quantitative and data-rich hand to design imagination,
then designers have ample opportunity to enrich LCA practice through exper-
imentation in the art of data interpretation, visualization, and communication.
[FIGs. 3-7]
Addressing climate change and other environmental impacts is not the work of
any single discipline. It is a collaborative pursuit, an active conversation — the
work both of big ideas and millions of small actions. Architects do not need to
reinvent the science of risk analysis or the characterization of environmental
impacts. They do not need to transform themselves into amateur toxicologists
or ecologists. What architects need to do is actively collaborate with industries
and practitioners who are more experienced at conducting such assessments
to make flows of materials and chemicals up and down the supply chain more
transparent and comprehensible. They need to join the conversation. In doing
so, architects must also bring to the table their considerable skills and exper-
tise, their understanding of how things get built, their creativity and prob-
lem-solving abilities, their great talent at translating complex systems into
accessible stories.
Climate change has made it abundantly clear that measuring environmental
impacts matters. But to address climate change in any real way — in a way that
systematically overhauls structures of power and production, and radically
rethinks how we use and manage resources globally — requires a shift in social
behavior and in the culture of our thinking.14 It requires us all to become more
educated and articulate in explaining climate change and in our understand-
ing of the relationship between our actions and large-scale impacts.
By modeling full material systems, life cycle assessment may prove to have
richer narrative potential than more reductive embodied energy calculations.
From a global warming perspective, embodied carbon is far more important
than embodied energy. Unlike simple calculations of embodied energy, a sin-
gle LCA model has the ability to distinguish between specific environmental
impacts. While the wide range of impact categories can be overwhelming, 14 Naomi Klein, This Changes Everything: Capitalism vs. the
Climate (New York: Simon & Schuster, 2014).
models that reveal connections between design elements and their environ-
mental impact, and then allow designers to explore trade-offs, are more use-
ful than those that reduce those environmental impacts into megajoules. In
truth, the numbers themselves are not really the point. When investigations of
environmental impact are integrated into design, the goal is not simply to hit a
baseline but to cultivate a practice of iteration, exchange, and exploration.
