Green building is not a novel concept. However, incorporating green building into new homes and structures has exploded in popularity in just the last two years. Green building has many environmental benefits, everything from improved air quality to conserving energy. Going green increases the overall efficiency of buildings and their sites by harvesting energy, water and re-using materials. By developing better designs and executing improved construction, operation and maintenance, individuals are able to create a general sustainability. Ultimately, this allows for reduced building impacts on human health as well as the environment.
With today's population becoming more and more conscious of growing environmental concerns, home builders and owners have felt compelled to take action. The National Association of Builders (NAHB) has produced the "Green Home Building Guidelines," allowing both builders and potential consumers the opportunity to create an environmentally friendly home. It was only after thoroughly reviewing green homebuilder programs, energy-efficiency programs endorsed by NAHB, and the leading life-cycle analysis tools obtainable for residential design and construction that NAHB was able to apply specific criteria to the building process and pave the way for countless environmental benefits.
Builders can follow the green home building guidelines and attribute the point system assigned to every individual aspect, thus allowing builders to be graded based on their abilities to create a "green" house. In turn each home can be awarded one of three different green building levels; bronze, silver and gold. By breaking up the building process into eight different categories, every single aspect of home design is covered thoroughly.
The Guidelines and Point System
The first category involves lot design, preparation and development. Environmentally efficient site design and development aid in reducing nature's natural impacts. Within this group, builders must take into account the site on which they're building, avoiding sensitive areas and aiming to build on infill and greyfield sites. The team who is responsible for designing and constructing the building must also have a vast knowledge of the goals established within the group for that particular job. When the builder is designing the site, it is crucial to conserve natural resources and minimize the slope disturbance, which involves the long term effects of erosion. Soil disturbance must also be minimized and landscape plans must limit the water and energy demand while enhancing the natural environment. A builder can earn a bronze award if they achieve eight points, silver if they reach ten points and a gold award if they achieve twelve points.
The second category relates to resource efficiency. Some of the most sensational green homes were created because the builders considered the environmental surroundings before the building phase. Builders are then able to maximize function during the design phase in which they produce resource-efficient plans. By allowing resource efficiency to be taken into account, the builders can reduce jobsite waste and maximize their materials in such cases where log is converted into lumber. Guidelines taken into consideration in this category include the reduction of the quantity of materials and waste, enhancing durability and reducing maintenance, and the reuse, reduction and recycling of materials consumed and left over at the end of each project. For the building company to earn a bronze level of green building they must receive 44 points, silver is 60 points and to be awarded gold the builder must receive 77 points.
The third issue included in the checklist and guidelines is energy efficiency. Energy consumption has increased and continues to increase, creating environmental impacts which build up over time. That's why green building is so essential to new and even existing homes. If every builder reduced the amount of energy they used during the production of materials as well as construction of each house, it would not only save the future homeowners money on energy bills but it would help save the environment. Such things builders must consider while trying to construct and build an energy efficient site and home are heat, water, insulation and lighting. It's vital for the home to be constructed in such a way that it uses insulation to the max, keeping the home warm in the winter and cool in the summer, limiting the amount of energy required to operate the furnace and air conditioner (if present). Energy efficiency relies heavily on the builder and their team. However, it's important for the homeowner to identify any extra features they want to include in their home. Such energy efficient tools include solar water heating systems, occupancy sensors for lighting control and heat pump water heaters. In this particular category builders can be awarded bronze if they receive 37 points, silver if they reach 62 points and a gold level of green building if they achieve 100 points.
The fourth category regards water efficiency. Green homes can allow for water conservation which is vital in drought areas. The scarcity of this resource has come to the public's attention recently, highlighting the importance of water usage and waste. When designing and building green the builder must take into account both indoor and outdoor water use. If such building is taking place in remote areas, hot water delivery is most effective when aided by installation of both an on-demand water heater and control-activated recirculation system. Installing water-efficient sink faucets and ultra low flow toilets can help lower the amount of water waste by the homeowner, ultimately saving them money on bills and conserving water for future generations. Other options for conserving both indoor and outdoor water include weather-based irrigation systems, collection and utilization of rainwater as permitted by local code, and installing a water-efficient showerhead to control the flow rate. The builder can receive a bronze level of green building if they achieve 6 points, a silver level if they reach 13 points and a gold level of green building if they achieve 19 points.
Indoor environmental quality is one of the main issues that draw individuals to green building. The home's indoor air quality is a very important aspect to homeowners, some having it as their top priority. There has been a heightened awareness over the years of what individuals inhale in their homes due to reported allergies and respiratory issues as well as the use of chemicals in the building process. Some existing homeowners have taken it upon themselves to add air filters within their homes, ensuring better air quality for their families. When builders are creating a new home it is key for them to consider minimizing the potential sources of pollutants. Some tactics that can be used for this are to install direct vent sealed combustion gas fireplaces, sealed wood fireplaces, or sealed woodstoves, or to not install a fireplace or woodstove at all. Managing pollutants that are generated in the home can be done by providing mechanical ventilation and controlling it automatically or continuously with manual override. Protecting unused moisture-sensitive materials from water damage and storing unused materials in a dry area can help improve the air quality. By performing some of the above examples builders can be awarded a bronze level of green building if the points equal 32, silver level of green building if the points awarded come to 54 and a gold level of green building if the points given add up to 72 or more.
The sixth category NAHB has placed on the point system is operation, maintenance and homeowner education. Homeowner education informs homeowners of their responsibilities towards maintaining their home and making it the best green home possible. By informing homeowners, they learn how to properly operate and maintain specific procedures such as changing air filters or operating bathroom and kitchen exhaust fans in order to eliminate moist air. In order for builders to be rewarded with points for green building for this category they must supply the homeowners with a home manual on the care of the home which should include the following: clearly labeled diagrams showing safety valves and controls for major house systems, a list of habits and actions to optimize water and energy use, information on how to enroll in a program so that the home receives energy from a renewable energy provider, and household recycling opportunities. The above provide some guidelines on what homeowners should be doing and following to maintain a green lifestyle. After all, once the construction of the home is complete and the builders have left, it's up to the homeowners to live a green lifestyle. To maintain a bronze and silver level of green building builders must receive 7 points, and to receive a gold level, builders must receive 9 points minimum.
Global impact is a leading issue to consider while building and decorating new homes. While builders are working on a new home it is necessary for them to consider what products they're using and how they impact the surrounding environment. When picking paint, one should choose low or no-VOC indoor paints. The VOC concentration of indoor paints should be equal to or less than the concentration specified by the EPA's Environmentally Preferable Purchasing Program. Flat interior latex coatings should be 100 grams/liter and non-flat interior latex coatings should be 150 grams/liter. Interior oil-based paints should be 350 grams/liter. The builder's operations and business performance should include environmental management system concepts, meaning that the builder must be ISO 14001 certified. To receive a bronze level of green building the builder must account for 3 points. In order to achieve the silver level the builder must receive 5 points and for the gold level of green building they will need 6 points.
The final category listed in the guideline created by the NAHB centers around site and land development. Green building doesn't stop once the home is finished. Going green involves the community, site planning and land development. Developers must consider the entire community and existing buildings to strengthen the benefits of green home building. The builder has the ability to influence not only the efficiency and effectiveness of each home but of the entire community's overall environmental footprint. Many of the guidelines in this category relate back to lot design, preparation and development, establishing the importance of a knowledgeable team, and picking an environmentally friendly site while avoiding environmentally sensitive areas. When designing the site the builders must consider conserving natural resources and vegetation and participating in natural resource conservation programs. The builders must aim to reduce long-term erosion, minimize slope and soil disturbance, as well as preserve and utilize natural water and drainage features. Grouping plants with similar watering needs, preserving wildlife and instituting wildlife habitat measures allow for a full circle of green building. Reducing street widths and sharing driveways and parkways will ensure that wildlife and environmental surroundings are preserved. Builders must take in all this information and put it towards their customer's needs and wants as well as their own goals.
Homeowners and Green Building Benefits
The benefits of green building far outweigh the costs for homeowners. By being environmentally conscious, homeowners can not only lower their operating costs but also increase their comfort with regards to temperature; green homes produce fewer drafts and stronger humidity control. Green homes have an added benefit of improving environmental quality. Building green enhances durability, thereby requiring less maintenance in and around the house.
Timber Frames and Green Building
Timber is an organic, non-toxic and naturally renewable material used for building timber frame homes. When using timber frames to design a home, the lighter timber buildings have a quick response to temperature changes compared to other materials used to build homes. Because timber has such good insulating properties, less heat is required in the winter months and less air conditioning in the heat of the summer months. In fact, heat is absorbed inside the inner leaf, ensuring that no heat is lost, which often reduces heating costs by up to 50%. The replanting of timber trees is ensured, promising this to be a renewable resource for years to come. With extra additions placed both inside and outside the home, a timber frame home is very practical for green home builders and those who would like to live a green life.
To further your understanding of green building concepts and for specific details of how to implement these concepts, as well as the point system for building a green home, access the NAHB's "Green Home Building Guidelines," available online at the NAHB Research Center website: www.nahbrc.org/greenguidelines/.
written by Rebecca Mader