Enhancing Sustainability Through Materials and BIM

By: Senior Architect Product Specialist Sarah Barrett, Assoc. AIA

Sarah Barrett brings more than a decade of experience as an architect and graphic designer, as well as professional expertise in the field of parametric modeling, to her role as a Senior Architect Product Specialist at Vectorworks, Inc. In addition to serving as an architectural expert and BIM specialist for the company, Sarah helps create best practices for Marionette, the integrated algorithmic modeling tool in Vectorworks software. She also leads webinars and workshops on a variety of industry topics and develops materials to help customers improve their workflows and design processes. Sarah has an M.Arch. from the University of Michigan and a B.A. in architectural studies from Brown University.

‘Sustainable construction’ and ‘green building’ are concepts that have gone from novel to trendy to mainstream over the past few decades. These are both very broad concepts that encompass plenty of different strategies, methodologies, and approaches, and quite often have specific connotations for each individual designer, however, the commonality we all share is creating designs that lead to the health, safety, and welfare of our clients and ourselves.

Sustainable construction and building practices, overall, seek to minimize negative impacts and cultivate long-term positive impacts on all project stakeholders, including occupants, surrounding communities, and developers. There are many methods designers can take to meet this end goal, however, here are a few ways to approach enhancing sustainability.

Following the Seven Principles of Sustainable Design

In their article, “Greening Project Management Practices for Sustainable Construction,” Lauren Bradely Robichaud and Vittal S. Anatatmula define seven core principles of sustainable construction that provide a helpful guide to those seeking to enhance sustainability in their projects and day-to-day practices.

These principles include:

• Reducing Resource Consumption—Using or specifying longer-lasting materials means that materials need to be replaced less often and therefore result in less consumption overall. Designers can also focus on creating less material waste during construction—this takes planning and coordination to achieve and is made much more feasible with Building Information Modeling (BIM) software. Reducing resource consumption can also refer to energy resources—designers can specify more efficient systems in their designs, resulting in less overall energy use.
• Reusing Resources—Specifying materials that can be reused or recycled with minimal processing, including renewable energy sources.
• Using Recycled Resources—Specifying products that contain recycled content contributes to a circular economy while also contributing to a project’s overall design concept. Utilizing reclaimed wood, metal or stone can serve as an aesthetic statement.
• Protecting Nature—Reducing the overall impact of your design on the environment. Not only is it important to think of the site of your project, but also the environmental impact of harvesting and transporting the materials to construct it.
• Eliminating Toxins—It’s important to specify materials, finishes, sealants, and other materials without volatile organic compounds (VOCs). VOCs include a broad array of mostly human-manufactured chemicals that off-gas into the environment and are one of the biggest contributors to poor indoor air quality. They can be found in paints, varnishes, adhesives, composite wood, and foam. Common VOCs include formaldehyde, toluene, benzene, and ethylene glycol. Phthalates are another group of toxic compounds used to make plastics more flexible and resilient and are often found in PVC, carpet, vinyl, upholstery, typical flooring and wall coverings, acoustical ceiling surfaces, and electrical cord insulation.
• Applying Lifecycle Costing—It’s critical to consider not only the impact but the cost of a building from “cradle to grave.” This type of lifecycle assessment term implies the life of a building from the “birth” or sourcing of its raw materials through their manufacturing, transport, and installation on the site; as well as throughout the building’s lifecycle and the energy it uses until the building is decommissioned.
• Focusing on Quality—Higher quality materials, though more expensive at the onset, often cost less in the long run because they last longer and work better. High-quality materials that are free of toxins and have less of an environmental impact when manufactured, while still high performing, are ideal.

(Before/After of a Lake Bluff home. Embodied carbon was saved by keeping the existing building instead of tearing it down. Photo by 2022 Kipnis Architecture + Planning.)

Calculating Embodied Carbon

The building sector makes up nearly 40 percent of annual global CO2 emissions and more specifically, building operations and energy usage make up 28 percent and the manufacturing of materials and construction make up 11 percent of global emissions annually. These emissions from materials and construction are what are typically referred to as embodied carbon. Embodied carbon is different from operational carbon, which concerns in-use operations like heating, cooling, lighting, and ventilation. The key is that operational carbon can be reduced after a building is constructed; embodied carbon, on the other hand, is locked once the structure is built.

Because the building sector is responsible for such a large percentage of CO2 emissions, it’s critical for the AEC industry to lead the way in reducing embodied carbon—and to think about net-zero benchmarks from the very start of the design process. In fact, many governments and legislative bodies are targeting net-zero carbon emissions in building operations and construction. For architects, targeting net-zero carbon means that analyzing projects’ environmental footprints are more important now than ever.

To reach true net-zero carbon emissions, you need a way to calculate embodied carbon throughout the entire lifecycle of a project. While it may be easy to say that determining this is too complicated, BIM software like Vectorworks Architect and tools like Vectorworks Embodied Carbon Calculator (VECC) make it simpler than you might think.

VECC is a tool created specifically for this purpose. The tool is a pre-formatted worksheet that has built-in formulas to calculate material embodied carbon emissions based on your inputs.

(Image courtesy of Vectorworks)

The VECC is organized into columns corresponding to stages of the project’s lifestyle:

• Product Stage – for tracking embodied carbon emitted from the supply, transport, and manufacturing of selected raw materials.
• Transportation Stage – for tracking carbon emitted from the transportation of products from the manufacturing plant to the project site.
• Construction Stage – for tracking carbon emitted from any on- or off-site construction-related activities.
• Replacement Stage – for tracking carbon emissions associated with anticipated replacement of building components.
• Deconstruction & Demolition Stage – for tracking carbon emissions arising from any on- or off-site deconstruction and demolition activities.
• Recovery/Recycling Stage – for tracking carbon emissions associated with treatment and processing of materials and components that are intended to be recovered and reused after the end of the built asset’s lifecycle.
• Disposal Stage – for tracking carbon emissions arising from the disposal of materials and components not expected to be recovered and repurposed but incinerated or disposed of at a landfill.

Using Marionette, Vectorworks’ built-in algorithmic design tool, you can even extract data from the VECC to visualize it into a chart.

(Image courtesy of Vectorworks)

Utilize Non-Toxic Materials and Greener Alternatives

While it’s crucial to understand and limit the impact building materials have on the environment, designers also have a responsibility to consider the impact materials in a building have on its occupants. Most are familiar with many of these common building materials but may not be familiar with some of the latest, greener alternatives they could consider.

Insulation
Insulation may not be something that an occupant comes into direct contact with, but toxins in insulation can still affect indoor air quality. It’s important that insulation be effective to have an energy-efficient building, especially in regions of extreme temperatures, but that doesn’t necessarily mean they need to be produced using fossil fuels or contain toxins. A few effective insulation materials that contain no VOCs or other toxins include sheep’s wool, hempcrete, and strawbale.

• Sheep’s wool is an excellent choice for insulation because it is an abundant renewable resource as well as an effective thermal and acoustic insulation. Wool is inherently moisture resistant as well as fire-resistant, so it doesn’t need added mildewcides or flame retardants. Wool also absorbs harmful chemicals, so it is not only toxin-free but actually improves air quality.
• Hempcrete is not necessarily insulation, but a complete wall system. It is made from hemp hurd, lime, and a hydraulic additive and installed with structural support. Lime in hempcrete uses 80 percent less energy than when used in concrete. From a carbon smart perspective, hemp is already an agricultural by-product, and it sequesters carbon, so it has a negative carbon impact. It is naturally fireproof and mold resistant, deters insects and is extremely durable with a lifespan of centuries as opposed to decades.
• Strawbale is a method of construction that uses straw from wheat, rice, rye, and oats. It’s an agricultural by-product that is plentiful in the U.S., making it a cost-effective option when sourced locally. The important thing to note about this alternative is that it is only suitable for dry climates—in climates of persistent humidity of 70 percent or above, dry rot can develop if the system is not allowed to breathe.

(Image courtesy of Vectorworks)

Interior Finishes
One of the biggest contributors to poor indoor air quality is paint. Since paint coats nearly every wall and ceiling in a space, it is ubiquitous and in direct contact with the air in a building. Paint also has traditionally had high levels of VOCs that not only off-gas when the paint is wet but persist in the air long after the paint has dried. Both latex- and oil-based paints contain VOCs, but there are many brands of latex paint on the market that are zero-VOC. While this doesn’t necessarily mean that a paint product is completely devoid of VOCs, the levels in the product are below 5 grams per liter and much lower than traditional latex paint.

There are, however, truly non-toxic paint options that are all mineral paints. Examples of mineral paints are milk paint, clay paint, lime paint, limewash, and chalk paint. Milk paint is one of the oldest known types of paint and it is made from milk, clay, and natural pigment, making it non-toxic and biodegradable. Milk paint is purchased as a powder and must be mixed with water right before applying. This makes it more labor-intensive than traditional paint, and poor mixing can result in lumps and a streaky finish. It must be used within two days of mixing, and it must be sealed. Sellers of milk paint often have non-toxic sealants as well. Because the pigment is natural, there can be variations in the color, but this doesn’t necessarily have to be a disadvantage. The paint has an iridescent quality and can achieve some interesting finishes. Clay paint tends to be thicker, almost like plaster, and therefore has a tinted, natural appearance like adobe. Chalk paint has a matte finish but often doesn’t come in a wide variety of colors. Most of these paint types have unique finishes, making them exciting non-toxic alternatives to traditional latex and oil paint.

Embracing Sustainable Construction
All in all, sustainable construction should no longer be a specialized practice. We as designers should be doing our part to reduce global carbon emissions and build safer, healthier spaces. Green building practices don’t have to mean compromising on design or aesthetics. Designing sustainably means thinking about a project on multiple scales and as a fully integrated system. A systems approach calls for data-driven workflows that allow us to efficiently iterate and optimize our designs. There’s a lot to learn and discover as an industry, but with a concerted effort, we can all embrace sustainable construction and help limit the effects of global warming.

This entry was posted on Thursday, April 21st, 2022 at 4:40 pm. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.