COST EFFECTIVE DESIGN PRINCIPLES FOR SUSTAINABLE PROJECTS

March 2023

By Christian Garcia, LEED AP BD+C, Homes, WELL AP

One common misconception about green building projects is about cost. While it is true that some materials, equipment or active design strategies come with a higher initial investment, having a more sustainable project does not need to come with an added cost. It is also true, third-party verification programs have a cost for registration and certification to cover the cost of reviewers, support research and develop continuous education material. However, a project is not required to pursue a certification in order to be designed and built with sustainability in mind.

The world is headed to start building zero or even positive carbon. At this point, while it is achievable and recommended to take all projects towards that direction, resources and knowledge are not always available and it makes the task challenging.

Project teams, owners and stakeholders should not feel discouraged to take their projects as far as they can in terms of sustainability. Every single decision made during a project is helping reverse, or at least push the brakes, on the effects of the construction industry over the environment and our health. Nowadays the market offers more options than it used to a couple of decades ago. Demand has made it possible to access more environmentally friendly, healthier, and energy efficient materials at no additional cost than the traditional options. Specifying these types of products is still required as a best practice and caution is advised due to greenwashing marketing.

I have come across different resources regarding no-cost or low-cost strategies that give us a clear idea of how we can start having a positive impact with our design regards resources such as energy, water, building materials and indoor environmental quality. The ultimate goal, from my perspective, would be to have all design professionals start a project under this thought process.

In some cases we cannot control situations like orientation, climate or even scale of the project. Maybe some principles would be more beneficial than others in our line of work. Some principles may now be even allowed because of the applicable building code depending on the country we are in. The important thing is to dive into what we can do before adding cost through more expensive equipment or materials.

While this list is based in the Global Green USA. Top 20 No or Low-Cost Green Building Strategies (1), it has been modified with additional information, personal interpretation and updated figures. This is not reinventing the wheel but a reminder there is more we can do regarding sustainability if we go back to the basics. These paragraphs do not intend to replace any green building rating system or set a standard. It is merely an introduction for those afraid of sustainability because of its cost.

Energy

• Light-colored roofs:

Depending on the location of the project a high reflectance index on the roof material could reflect up to 80% of sunlight (2) contributing to maintain the comfort inside the space while reducing cooling loads. The lighter the higher SRI (Solar reflectance Index) could be and, less heat could be absorbed through the roof.

• Daylight:

Access to daylight through windows, transoms or skylights with the right orientation (west, east or south) could reduce the energy consumption from artificial lighting.

• Overhangs and screening(south glazing):

While daylight is encouraged for energy savings and human wellness, protection through overhangs or screens reduces the direct heat gain to the spaces and cooling loads. An overhang may even help reflecting light towards the ceiling, maximizing its use without glare.

• Natural Ventilation:

Cross ventilation would be the best approach to reduce the building cooling loads naturally. If this is not possible to implement due to specific project conditions - and depending on climate, code and safety regulations - access to operable windows is still encouraged to reduce cooling loads.

• Use of fans:

Cooling loads and energy consumption could be reduced while air circulation can be improved if appropriately installed.

• Energy efficient lighting:

The use of high efficiency light bulbs could use up to 90% less energy compared to standard bulbs. Also, the production of heat would decrease by 70-90% (3).

• R-Value Study:

An appropriate study of the R values for exterior wall, roof and floor assemblies (taking in account codes and regulations) could increase the comfort within the space while reducing cooling and heating loads.

• Energy Star Products:

The installation of third-party verified products regarding their efficiency could reduce energy consumption and heat loads within the space. A product finder can be found here: https://www.energystar.gov/products?s=mega

• Is air conditioning necessary?

Sustainability doesn’t apply only to a specific country or region in the world. While extreme weather climates may require the installation of HVAC systems, some areas could benefit from not having an air conditioning installed and study further the benefits of natural ventilation to reduce significantly energy consumption.

Water

• Low consumption fixtures:

Installation of toilets, faucets, urinals, showerheads and/or irrigation equipment that are water efficient, or in other words, consume less water during their use. WaterSense is a label given to products that meet EPA’s specification for water efficiency and performance (4) and acts as a third-party verification program. Products with this label are about 20% more efficient than the average product in each category (4).

• Native vegetation:

Having vegetation used to the climate where the project is, could help with the reduction of water for irrigation. If irrigation is required, systems like drip irrigation will further help with water savings.

• Permeable paving:

Installing porous materials for paving will reduce the runoff of stormwater recharging the groundwater. Also, certain areas could contribute to the prevention of flooding (5).

• Rainwater harvesting:

These systems can be designed as simple or as complex as desired depending on the type of project. Harvesting rainwater could help save water for irrigation, cleaning or even toilet flushing. The design team needs to be aware of existing (or unexisting) regulations for rainwater harvesting and storage.

Materials

• Recycled content:

Certain construction materials like insulation, drywall and/or carpet can be specified to have recycled content which diverts waste from landfills. It is important to double-check that such products went through a third party verification to find clear data about the product.

• Engineered wood products and FSC

While wood products come from a renewable source, forest cannot regenerate as fast as we harvest. Therefore, specifying wood that is part of a forest certification program assures the design team the product comes from a responsible forest management practice. Also, specifying engineered products reduces the demand of cutting old growth forests and the embodied energy of the material when compared to concrete or steel (8).

• Use of flyash

Fly ash is a byproduct of coal combustion from power plants, so it’s basically the particles of the flue gas that come out of the furnace, and then that's captured and reused (9). Its cementitious properties make this product a replacement for Portland cement on concrete mixes, decreasing its negative effects over the environment.

• Regional materials

One of the lessons we can take from vernacular architecture - from around the world - is the use of regional materials. Their impact over the environment decreases because their embodied energy decreases as well. Plus, depending on the project, the use of local materials could be beneficial for the performance of the building in that particular climate (rammed earth or adobe for example).

Indoor air quality

• Low or No VOC:

The indoor use of products with volatile organic compounds (VOCs) can bring consequences to human health. The effect could be as mild as eye, nose and throat irritation, headaches, nausea, worsening of asthma symptoms all the way to cancer, liver and kidney damage, as well as damage to the nervous system (10). Specifying paint, adhesives and cleaning products with low, and preferable no VOCs is the responsible thing to do for the occupants of our projects.

• Formaldehyde-free materials:

Similar to the chemicals above, formaldehyde can have negative effects on human health. It is a component of glues and adhesive mostly found in carpentry products on our projects. When specifying pressed wood products, it is important to add a formaldehyde-free requirement to the specification.

Before adding extra cost to projects by selecting the latest technology or system available, design teams could exhaust all possibilities and question each of the previous items and even beyond: Is this the best orientation? Is this the best shape/volume for our building? Is the location of windows answering to pure aesthetics or to maximize daylight? Is cross ventilation an option? Do we need AC at all? What is done to maximize water savings? Is wood an option vs. steel? Can steel members be recycled from another project?

1. Global Green USA (n.d.). Top 20 No or Low-Cost Green Building Strategies, 2003. Retrieved October 17, 2016, from www.globalgreenusa.org *no longer available*

2. ENERGY STAR (n.d.). Cool Roofs. Retrieved March 6, 2023, from https://www.energystar.gov/products/roof_products/cool_roofs_emissivity

3. ENERGY STAR (n.d.). Light Bulbs. Retrieved March 6, 2023, from https://www.energystar.gov/products/light_bulbs

4. US EPA (2022, May 23). The WaterSense Label. Retrieved March 6, 2023, from https://www.epa.gov/watersense/watersense-label

5. Sjolander, S. A. (2022, June 26). Roadside Guide to Clean Water: Porous and Permeable Paving Materials. Retrieved March 6, 2023, from https://extension.psu.edu/roadside-guide-to-clean-water-porous-and-permeable-paving-materials

6. Washington State Department of Ecology (n.d.). Rainwater collection. Retrieved March 6, 2023, from https://ecology.wa.gov/Water-Shorelines/Water-supply/Water-recovery-solutions/Rainwater-collection

7. Innovative Water Solutions LLC (n.d.). Rainwater Harvesting 101. Retrieved March 6, 2023, from https://www.watercache.com/education/rainwater-harvesting-101

8. APA Sustainable Buildings, Sustainable Future

9. Gombeda, M. (2021, October 13). Searching for a Sustainable Solution: Using Fly Ash in Concrete Mix Designs. Retrieved March 6, 2023, from https://www.iit.edu/news/searching-sustainable-solution-using-fly-ash-concrete-mix-designs#:~:text=And%20fly%20ash%20is%20a,It's%20sustainable

10. Minnesota Department of Health (2022, October 20). Volatile Organic Compounds in Your Home. Retrieved March 6, 2023, from https://www.health.state.mn.us/communities/environment/air/toxins/voc.htm#:~:text=Volatile%20Organic%20Compounds%20(VOCs)%20are,the%20indoor%20air%20we%20breathe

OTHER RESOURCES

Connecticut Housing Finance Authority (2021, September 1). Construction Guidelines: Energy Conservation & Sustainability 2021. Retrieved March 6, 2023, from https://www.chfa.org/assets/1/6/2022_ConstnGuidelines-EnergySustainability_9_30_2021.pdf?10358

APA – The Engineered Wood Association (n.d.). Design Solutions: Green Building. Retrieved March 6, 2023, from https://www.apawood.org/green-building

US EPA (2022, October 27). What should I know about formaldehyde and indoor air quality? Retrieved March 6, 2023, from https://www.epa.gov/indoor-air-quality-iaq/what-should-i-know-about-formaldehyde-and-indoor-air-quality