Growing Buildings

We often tend to focus on commercial projects when discussing what steps can be taken to construct green buildings.  However, green construction has also taken off in the residential market and there are a variety of different building products and techniques available.

One of the more interesting products I have come across lately (LINK) is called Hencrete.  Hemcrete is composed of hemp, lime, and water, and is being used to construct sustainable carbon negative building components.  The final product is a durable material that provides an airtight seal and can be used in many areas where traditionally framed walls would be used.  One advantage of Hemcrete is that it is very adaptive to changes in humidity and will not rot like a traditional wall if water is allowed to infiltrate the wall.  The biggest breakthrough with this new product is that it is carbon negative.  This means that there is more CO2 locked up throughout the growing and harvesting process of the hemp than the amount of carbon that is released during the production of the lime, which is used as the binder.  This is a very difficult accomplishment to achieve and could make Hemcrete a very popular product for using in future sustainable structures. 

Hemcrete can also be used for other building elements such as roof insulation and flooring.  Unlike traditional building materials, 100% of the product can be recycled when the structure is deconstructed.  Although a wall made out of plants may seem like a fire hazard, Hemcrete is actually fireproof due to the lime binder coating the plant material.

One issue with using Hemcrete is that it is currently priced much higher than traditional wall materials.  However, as the popularity of this product begins to grow and production costs decrease, Hemcrete could become a very common building product.  Unfortunately, the species of hemp required to make Hemcrete is illegal to grow in the United States, but the product has become extremely popular in Europe and other countries.  Advocates of sustainable construction are working to change laws to allow Hemcrete to be grown in the US, instead of having to import the product at high costs.

Below is a video demonstrating the production and application processes of Hemcrete:

We Can Reduce Greenhouse Gas Emissions, but Will We?

A Green Building Elements article (LINK) explains a study conducted at the University of Toronto concerning the reduction of greenhouse gas emissions.  Large cities account for the majority of greenhouse gas production.  The methods to reduce these emissions are readily available, but the problem is that they are difficult to implement.  Not every building can be torn down and rebuilt or retrofitted to operate more efficiently and have less of an impact on the environment.  Over time, buildings will have to be deconstructed due to age and can be rebuilt with sustainability in mind, but that will be a long and lengthy process.

The most logical and cost effective first step to take towards reducing greenhouse emissions is to educate citizens on practices they can adopt to help.  A combined effort of the majority of citizens in a particular city can have an enormous reduction of emissions.  The United States Environmental Protection Agency publishes a number of small steps (LINK) that citizens can take to reduce greenhouse gas emissions.  In the world of construction, we get caught up in how we can build something new and sustainable, but sometimes big changes can come from small improvements to items we already have.  For example, in our homes we can use energy efficient light bulbs, choose Energy Star products, use the thermostat wisely, add insulation, recycle, reduce water usage, and purchase green power.  Outside our homes we can commute in fuel efficient vehicles, use renewable fuels, or use alternative methods of transportation such as bicycles or public transportation (EPA 2013).

Existing buildings can help promote alternative means of transportation by adding bicycle racks or applying to have a bus stop closer to their building.  The idea of having all green buildings sounds great, but we will never be able to reach the lowest possible level of greenhouse gas emissions if people do not begin adopting sustainable practices into their daily lives.  Most buildings being constructed today are implementing at least some green building practices, even if they are very minimal.  Green building is continuing to grow at a rapid pace, and if it continues on this track, buildings will quickly be outperforming humans in efficiency.  If a large push is made now to encourage private citizens to use sustainable practices, the harm we are causing to the environment can be reduced much faster, by two of its greatest sources of pollution working together.

Are Green Buildings Risky?

One of the most common complaints about green buildings is that they are too expensive.  However, it has been proved that green buildings can be built for the same cost as a traditional structure, or if they do cost more, the extra cost will quickly equal out due to decreased operating costs.  One topic that is often not discussed is whether green buildings can have more problems than a traditional building.

An article published by the Associated General Contractorsof America (AGC) addresses other issues that owners and contractors may need to consider before deciding to build a green building.  The main focus of the article is that using new construction methods and materials increases the risk of potential problems.  As stated in the article, “Simply put, departing from the ‘tried and true’ often means increasing the risk of building failure.” 

One of the main risks involved with green buildings is the potential for moisture and mold issues.  Many green buildings encourage the introduction of outside air to achieve indoor air quality credits, while traditional buildings emphasize dehumidification.  Large amounts of outside air can lead to moisture and mold issues soon after the building is constructed.  A variety of other green building practices can also lead to moisture problems.  Vegetative roofs stay moist and can leak into the structure.  Many green buildings focus on insulation rather than repelling water.  Also, the increased insulation can change the dew point location in walls and increase condensation.  Recycled materials may not shed water as well as traditional materials.  Finally, some methods to improve air quality, such as “building flush out” may introduce an excessive amount of moisture into the building.

Another risk involved with green building is the number of new building products being introduced that claim to be sustainable.  Many of these new products have received a limited amount of testing and may fail to meet their advertised performance levels, compared with proven materials found in other buildings.  This could result in a shorter lifespan of the structure than anticipated and possible safety concerns.

All of these issues should be addressed when designing and constructing green buildings.  If any of these problems do occur, the owner may end up with a useless building.  This could result in a legal battle between the designer, owner, and contractor.  Repair and legal costs could quickly outweigh the money saved in operating costs by building a green building.  Therefore, special care should be taken to be sure that the building will be able to perform either equally or better than a traditional building.  The article recommends three steps to help achieve this goal.  First, a Climate Design Criteria should be developed to encourage the best practices for moisture control.  Next, a Green Building Risk Management Plan should be created to provide guidelines for building the project, as recommended by a variety of experts.  Finally, past projects should be used to determine what practices worked and failed.  Green building is growing at a rapid pace, and while it is wonderful for the environment, we must remember to maintain a high level of building quality so they can be used for many years into the future.

Hello, and welcome to my blog.  Over the course of this semester, I will discuss topics involving green building. 

Green construction is growing at a rapid pace and many owners are requesting at least some level of green certification.  Many construction companies are embracing green construction with open arms, but many contractors and subcontractors are not as willing to accept the extra effort that is required to certify a project.

Last summer I had a wonderful opportunity to work with a large commercial general contractor that specialized in large tilt-up warehouses.  The majority of their projects were required to be LEED certified, and I compiled all of the information required to achieve LEED certification for one of the projects nearing completion. 

The USGBC has done a great job creating LEEDonline, which allows contractors to submit all of the documentation required to achieve LEED certification digitally.  The contractor can log on to this website, enter the required information for each LEED credit, and upload any cut sheets or backup documentation.  After this is submitted, it is reviewed by the USGBC and either approved or denied, which can also be seen online.  Although this process is somewhat simple and straightforward, it can be very time consuming, especially for a small construction firm.  The main issue I encountered was actually gathering the information needed from the subcontractors.  For many subcontractors, sending the information required for LEED is ranked very low on their list of priorities.

Receiving LEED accreditation has become very common for prime contractors, but it is important to urge subcontractors to obtain training as well.  It would be wonderful if all subcontractors held a LEED AP certification, but that may be unrealistic.  However, a small amount of training would be beneficial to bring prime contractors and subcontractors closer together on understanding the importance, procedures, and requirements of green building.  Some workshops are already available for subcontractors to teach them the basics of LEED and the areas that they must participate in. (LINK) 

The description for a workshop in Massachusetts states, “LEED for Subcontractors is an opportunity to develop complementary skills that produce quality projects for today’s demanding green building clients.  The workshop aims to focus on particular areas where subcontractors must participate in the LEED process, namely providing documentation about materials and following policies and procedures for indoor air quality.  This workshop will explore in detail the on-the-job requirements affecting various trades.  There will be hands-on practice with material information sheets.  Small groups will provide an opportunity for discussion, questions, and feedback among subcontractors, designers, and general contractors.

Educating subcontractors about their role in LEED certification can be very beneficial to both the prime contractor and the subcontractors.  Having more subcontractors receive LEED training will be a gradual process, but could be accelerated by including in their contract that they must attend a “LEED for Subcontractors” workshop.  Most small construction firms do not have the time or resources to walk each subcontractor on a project through the requirements step-by-step.  With a greater understanding of the LEED requirements through training, the subcontractors can make this process much easier for everyone involved.