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DCI ENGINEERS: A TRUSTED & EXPERIENCED SUSTAINABILITY PARTNER
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LCA s , EPD s & GWP s — AN INTRO TO EMBODIED CARBON & DCI SERVICES
CONCRETE
STEEL
MASS TIMBER
With the majority of a building’s total embodied carbon released upfront in the product stage, we have an unprecedented opportunity and responsibility to impact meaningful change by way of the structure. Engineers can provide designs that focus on efficiency, low-carbon material procurement, adaptability and resiliency—ones that will outlive the many cycles of tenant improvements and building system upgrades for years to come.
In addition to our support of LEED-certified, Living Building Challenge and other sustainability-focused projects, DCI Engineers has signed on to the SE 2050 Commitment, promising to eliminate embodied carbon in our projects by the year 2050, while at the same time actively working to exceed this goal ahead of schedule.
By integrating sustainable components, project outcomes include:
» Reduced carbon footprint through the use of recycled steel, low carbon concrete, and sustainabilitysourced wood
» Increased certainty in a changing regulatory environment where Buy Clean policy, ESG-oriented investing, and carbon taxes are becoming more popular
» Added market value and differentiation for building ownership
» Improved mental wellbeing, physical health, and office tenant productivity due to the biophilic effects associated with the thoughtful use of wood products
The following brochure outlines DCI’s sustainability services and environmental solutions utilizing mass timber, steel, and concrete designs.
The building industry produces two distinct types of carbon—operational, which refers to the greenhouse gas emissions due to building energy consumption, and embodied, which pertains to emissions created from the manufacturing, transportation, installation, maintenance and disposal of building materials. Typically, half of the embodied carbon in a building comes from the structure. As structural engineers, we have an unprecedented opportunity to reduce the carbon footprint of the building industry when considering the societal and environmental impacts associated with our designs.
DCI’s comprehensive services include structural, civil, bridge and industrial work. While these services are distinct, they operate under our core values of Service Innovation & Value. Woven throughout is an obligation for more sustainability-forward thinking—from the materials we use to the tools and technologies we can apply.
Project-Specific Structural design, Life Cycle Assessment & Reporting
» Material Re-Use Evaluation: Existing Site Analysis, Tenant Improvements, Alternate Building Occupancy Adaptation, Reclaimed Material Recommendations
» Structural System Selection Using Life Cycle Assessment: Material Comparison, Structural System Exploration and Hybrid Options, Cradle-toGate Embodied Carbon Analysis, End-of-Life Building Considerations
» Optimized Structural Designs to Reduce Material: Castellated Beams, High Strength Structural Steel, Cement Minimization, High Strength Concrete Reinforcing, Wood Fiber Optimization, Composite and Hybrid Systems
» Modular & Prefabricated Design Expertise: Panelized Systems, Volumetric Modular, Component Assemblies, Manufacturer Coordination
» Mass Timber Design Expertise: Fire-Rated Member and Connection Detailing, Supplier Coordination for Maximum Layout Efficiency
» Performance-Based Design Expertise: Performance Objective Coordination, Material Supplier Collaboration for Performance Optimization, Research and Development of Alternate Analysis Methods
» Embodied Carbon Optimization and Tracking: Life-Cycle Assessment Software Expertise, MultiDisciplinary Design Coordination, As-Built Material Tracking
» Deconstructability & Resiliency Considerations: Connection Detailing for Future Building Decomission and Adaptability, Demolition Permit Coordination, Desired Risk Performance Implementation
Specification and Coordination of Reduced Carbon Materials
» Early Procurement Collaboration & Supplier Coordination
» Low Carbon Material-Focused Specifications
» Environmental Product Declaration (EPD) Evaluation & Tracking
» Green Building Rating System Assistance
Studies the environmental impact of constructing a building throughout its entire life cycle, including procurement, construction, operation and decomissioning.
Environmental impacts can be measured across a range of system boundaries, such as:
» cradle-to-gate reflects impacts from resource extraction and manufacturing processes up until the product leaves the factory
» cradle-to-grave includes impacts from resource extraction up until building decommission and material disposal
» cradle-to-cradle defines impacts from resource extraction up until building decommission, which includes reuse, recycle and recovery considerations
Measures the heat absorbed by greenhouse gas in the atmosphere. There are several other important environmental impacts to consider in an LCA, but GWP is the most common metric utilized to report reductions for green building rating systems.
A document that communicates comparable information about the environmental impact of a product, like a nutrition label. EPDs should be independently verified in accordance with ISO 14025 to be recognized by green building rating systems and Buy Clean policies
Concrete is used in nearly every structure, particularly for its strength, durability and resilience. Unlike other materials, concrete is more versatile and can adapt to all kinds of surfaces, shapes, textures and forms in any environment. Concrete construction can be sourced locally for nearly any project site and requires little long-term maintenance, translating to cost savings.
» Concrete is recyclable as it can be crushed and reused as aggregate for paving and subbase.
» Reinforcing steel can be infinitely recycled without any loss of quality.
» Concrete is highly durable and has a long product life cycle.
» Ordinary portland cement can be replaced with alternative cements and a wide-range of recycled supplementary cementitious materials, while also being optimized through the use of performance-based specifications.
Cement, a major component of concrete, is the source of nearly 8% of global greenhouse gas (GHG) emissions; therefore, DCI is actively reducing the amount of cement in our concrete structures as an essential step towards reducing our firm’s overall carbon footprint. When sustainability goals are coordinated with the project team early, concrete structures have the potential to capture large amounts of carbon savings with little to no impact on the budget.
With the introduction of building construction embodied carbon limits and environmental product declaration requirements by government regulations and stakeholders; manufacturers are motivated to explore new products and practices.
Our sustainability department has partnered with cement, concrete and specialty product suppliers across the country, allowing us to identify and recommend embodied carbon reduction strategies most appropriate for a given project and region. Using performance-based specifications, based on a set of clear, measurable and enforceable instructions; allows us to give suppliers the freedom to create the most efficient concrete mixture that minimizes cement while still meeting the necessary structural requirements.
While hot-rolled, structural steel is typically comprised of over 90% recycled content, the carbon footprint of steel is still quite significant compared to other building materials as its production is a major contributor of green-house gas (GHG) emissions. The good news is there is ample opportunity to reduce the embodied carbon of steel used in our industry through the implementation of material optimization and coordinated procurement strategies.
Steel contributes GHG emissions not only to the construction industry, but several other sectors that rely on the production of this material. Steel production contributes approximately 10% of global GHG emissions, so it’s important to consider how the power of procurement can have an impact beyond that of the building industry.
DCI has dedicated time and resources reducing embodied carbon associated with our steel designs. Helpful tools like life cycle assessment (LCA) and discussions with leaders in the industry, like the American Institute of Steel Construction (AISC), and the Steel Tube Institute (STI), have given DCI insight as to what can be done to reduce the embodied carbon of steel in the most direct way. We emphasize multiple design strategies to reduce the carbon footprint of our steel structures including:
» Material Quantity Optimization
» Targeted Material Specification to Prioritize EAF Facility-Produced Steel Sections
» Lateral-Force Resisting System Optimization
» Design for Prefabrication and Offsite Construction
» Design for Deconstruction and Re-use
North American hot-rolled structural steel is produced using recycled material almost entirely in Electric-Arc Furnace (EAF) facilities, which yields approximately half of the GWP compared to Blast-Oxygen Furnace (BOF) facilities, aka coal-burning facilities that use primarily raw materials. DCI has updated our standard specifications to promote the use of recycled material and less energyintensive manufacturing processes for this reason.
While the sourcing of steel is not something DCI can directly control, it is a metric that is crucial in understanding the carbon footprint of steel on our projects.
Steel is well suited for deconstruction, adaptability, and re-use. According to AISC, approximately 98% of structural steel is recycled at the end of a building’s life. This ability for deconstruction and adaptation plays a significant role in the full carbon life cycle of a project. When we recycle building material at the end of life or modify existing steel structure for new use, we greatly reduce the overall embodied carbon of that development.
Wood is the only building material that naturally sequesters carbon, making this an incredibly effective strategy to reduce the overall embodied carbon associated with the structure. When used in mass timber applications, these reductions increase exponentially and yield impactful improvements throughout the entirety of the building’s lifespan.
Mass Timber offers savings to the construction schedule and overall costs while helping to significantly reduce environmental impacts—when the right project partners are in place. DCI Engineers has the experience to assist in the planning, permitting and application of mass timber design. This kit-of-parts building method requires absolute and early coordination between project disciplines and unparalleled trust.
Engineered wood products utilize wood from responsibly managed forests not utilizing old growth. DCI works with many groups on climate smart and responsibly managed forestry practices as well as wood from forest restoration projects. Forest restoration wood is focused on creating healthier forests, better water quality, and reducing wildfire risks.
Mass Timber Saving: on construction schedule, overall project costs, finish costs, labor demand, traffic congestion (via fewer construction deliveries) and seismic weight.
While Providing: end-user satisfaction (biophilia), improved leasing velocity and practices for healthier forest management.
“A movement is growing to use heavy and mass timber as primary structural materials for medium-height and tall buildings, in large part because timber is renewable, stores carbon and is energy efficient.” -thinkwood.comAnkrom Moisan Architects
DCI’s services include cost-effective solutions for fire-rated member and connection detailing, composite wood and concrete systems, steel and timber systems and other types of hybrid structural systems. This understanding of materials involves integration into whole building design, along with MEP/F systems, acoustic design, cladding compatibility, fiber optimization, and vibrational analyses. DCI Engineers has designed low-rise, mid-rise, and high-rise (following the new Type IV construction types) projects with a multitude of occupancies.
DCI collaborates with a number of entities, both private and public, to explore innovative approaches and address whole-picture solutions for mass timber design and constructability.
Private Partners: include developers, architects, general contractors & timber suppliers to explore:
» Affordable housing
» Modular construction
» Moisture management
» Design-assist
» Builders risk insurance
» Proprietary connection development, seismic component development, and timber product development
Public Partners: include local & regional jurisdictions, industry and university organizations & the U.S. Forest Service to explore:
» Tall mass timber code adoption
» Performance-based design (PBD)
» Termite treatment
» Seismic systems
» Acoustics
» Point supported systems
» Fire ratings
» Detailing of fire rated connections
» Future tall mass timber design and analysis
A simple beam analysis will provide an idea of how the different materials used to design the same structural element can have a significant impact on GWP. The GWP metrics are selected from industry-average EPDs from the National Ready Mix Concrete Association (NRMCA), American Institute of Steel Construction (AISC), Steel Framing Industry Association (SFIA) and the American Wood Council (AWC).
Global Warming Potential (GWP) in kgCO2eq:
These graphics show the cradle-to-gate industryaverage GWP per pound of material versus the overall GWP content of the beam’s analyzed for a 20-foot span.
Note that while concrete has the lowest carbon intensity per pound, the weight associated with the concrete section far outweighs the other materials.
Plus, the need for concrete reinforcement proves a considerable impact when studying the GWP of the full design. However, it’s important to keep in mind each structural material has its own unique characteristics, for example concrete’s fire resistance and long-term durability, so it’s necessary to select materials with all relevant factors in mind.
