Green, Sustainable & Regenerative Design – I was inclined to create this three part series in order to discern the terms for LGA staff internally and hope that my research and deeper discovery into each of these concepts proves valuable for our readership as well. I begin the series with Green Design.
The U. S. Green Building Council (USGBC) devised a program called Leadership in Energy and Environmental Design (LEED) in the late 1990s. The LEED program provides for certification of four levels of Green Building Design: certified, silver, gold and platinum. The green strategies promoted by this program provide buildings that not only use less energy but also are healthier for the occupants. Some of these strategies include the following:
- Providing light colored pavement and roofs with a high reflectance to mitigate the heat island effect (absorption of sunlight and turning it into heat and releasing heat into the surrounding air).
- Cleaning rainwater from pavement areas before it gets into the ground water or natural storm water systems.
- Providing shading of south facing windows with shade devices or deciduous trees to prevent the summer sun entering the building increasing the heat load on air conditioning systems.
- Using reclaimed water for landscape irrigation instead of potable water.
- Using plumbing fixtures (urinals, water closets, faucets and shower heads) that use less water.
- Providing well insulated and sealed exterior walls and roofs lessening the air conditioning or heating load within the building, using less energy.
- Providing daylight to the interior spaces and lighting controls that decrease the use of artificial light during daylight hours, once again decreasing the load on air conditioning systems, using less energy.
- Providing recycled materials so that there is less harvest of raw materials.
- Providing locally harvested and manufactured materials and products mitigating transportation. Transportation reduces the use of fuels and therefore the release of carbon dioxide into the atmosphere.
- Provide a minimum standard of ventilation whether mechanical or natural.
- Use rapidly renewable materials.
- Use materials that do not contain material that harmful to the building occupants’ health.
- Providing window views to the out of doors for most of the occupants.
- Utilizing energy efficient heating, ventilation and air conditioning systems.
- Encourage the generation of on-site renewable energy (1 to 13 percent of the buildings energy use).
Green design provides a project that is more energy efficient, more friendly to the environment and better for the occupants than the standard building.
Green and sustainable as terms have been used interchangeably for some time. The term “sustainable” is defined by the Meriam-Webster Dictionary as “capable of being sustained.” A sustainable design would provide a project that can sustain itself.
As indicated in the conclusion of part 1 of this article, green design uses green strategies to attain a project that is more energy and water efficient and provides a healthy environment for the occupants. The next part of this article will concern sustainable design.
As discussed in Part 1, sustainable design must provide a project that is able to maintain itself (conserving an ecological balance by avoiding depletion of natural resources).
In order to maintain itself the final project would have to be carbon neutral, net zero energy use, net zero water use and maintain a comfortable and healthy environment.
Net zero energy use would mean that the designed project would have to generate all of the project’s energy requirements on site. This could be attained by using solar energy, wind energy, hydro energy or geothermal energy. In order to mitigate the high initial cost of these methods of onsite energy generation, project and occupant energy use should be lowered by using green strategies that lower energy use. Some of these strategies include the following:
- Daylighting to lower artificial lighting use.
- Well sealed and insulated building envelope to lower heating and air conditioning requirements.
- Use natural ventilation.
- Use higher reflectance materials on the exterior to prevent absorption of solar energy and heating interior spaces.
- Provide buffers such as vestibules between the exterior and interior spaces at access locations.
- Provide landscape shading of the building.
- Provide operable shutters, window shading that prevent direct sunlight entering the building but allow daylight and views during months that require interior cooling.
- Use thermal mass to slow the movement of exterior extreme temperatures to the interior.
- Use solar energy for heating in the cold months of the year (trombe wall).
- Use of solar heating for hot water.
These are some of the green strategies that may be used to lower energy use.
Net zero water use is more difficult to attain. In order to attain net zero water use, the project must recycle and collect water. Water use should be minimized by using strategies that lower the amount of water used. Many of these strategies will require life cycle changes by occupants. Some water use strategies may include the following:
- Use of low flow faucets and shower heads.
- Use of water closets that use less water to flush or better yet the use of composting toilets.
- Recycle all water including gray and black water by using an onsite constructed wetlands or living machine.
- Provide a water filtering process that allows recycled water to be sterilized for human consumption.
- Collect rainwater and storm water from the site to replace water lost to evaporation in the recycling process.
- Take shorter showers less often.
- Use hydroponics for food growth as it uses 90 to 95 percent less water than gardens.
These and other water strategies could cut water use to that being naturally collected.
Finally, a sustainable design should provide a comfortable and safe environment for its occupants. This can be attained by using products that do not contain chemicals that are harmful and cause health problems. Some of these harmful chemicals include:
- Volatile organic compounds
- Perfluorinated compounds
- Flame retardants
- Phthalate plasticizers
- Isocyanate-base polyurethane
- Carbon monoxide
No product that contains these chemicals should be used in a sustainable design.
In order for the design to be comfortable for the occupants the interior environment must provide comfortable levels of ventilation, temperature and humidity.
Now that I am at the end of Part 2, have you noted that I have not said a word about being carbon neutral? I have decided that a sustainable design would not necessarily need to be carbon neutral but a regenerative design would. We will get into that in Part 3.
Regenerative is defined as tending to restore to a better, higher or more worthy state. Regenerative design would, therefore, be a design that provides a project that not only restorative for the world and the surrounding area but also for the occupants. As such, the design would have to include green and sustainable strategies but also go beyond those strategies.
In part 2 of this article I ended by indicating that a regenerative design would have to be carbon neutral. In order to restore the environmental damage caused by man releasing greenhouse gases (GHGs include water vapor, carbon dioxide, methane, nitrous oxide and ozone) into the atmosphere a regenerative design needs to make up for all of the embodied or inherent carbon release that all of its components bring with them. The greenhouse gases (GHG) are normally expressed as carbon dioxide equivalents as carbon dioxide makes up approximately 50% of all GHGs released into the atmosphere by man. This includes the carbon release during harvesting of natural materials, during delivery of raw materials to the manufacturing plant, during manufacture, during delivery of product to the site and during the construction of the regenerative project. There are a number of calculators available to assist in calculating the embodied emissions in various construction types and materials. Some of these include: AggRegain, aspect, Build Carbon Neutral, Environment Agency Carbon Calculator, PAS 2050 Carbon Calculator for Stoneworks and the ICE Database. As manufacturers utilize less energy and more recycled product in their product, it is necessary to keep any database that calculates embodied energy up-to-date
In order to be truly regenerative and carbon neutral the design should also make up for the GHG release during the life of the design and the dismantling of the project at the end of life. This would include tenant improvements, renovations, additions, maintenance materials and cleaning materials.
One of the ways to assist in becoming carbon neutral is to be energy positive by producing more on-site clean energy than the design needs to sustain itself. Using solar, wind, hydro and geothermal sources to produce more energy than required and providing it back into the energy grid will assist in making up for the embodied energy within the project.
Other methods can be used to become carbon neutral. One would be to grow more trees on the site that could remove and store carbon from the atmosphere. Other methods could include the following:
- Discourage the cutting down of old forest by using only wood products that are FSC certified.
- Using less ornamental landscaping and utilizing food producing landscape such as fruit trees, nut trees and edible berry producing shrubs.
- Using hydroponics to grow interior planting that produces vegetables (hydroponics uses 90 to 95% less water).
- Using more recycled materials.
When you use recycled materials in a design, I consider the embodied energy to be the responsibility of the project from which they were salvage, therefore reducing the embodied energy of the regenerative project. Finding recycle materials such as beams and windows is a matter of hard work researching and finding the items you need.
I will continue to discuss regenerative design in Part 4 of this series. In Part 4 I will discuss water and biophilia.