Sustainable Building (Green Building)
Sustainable building is the practice of designing and constructing buildings to achieve all the requirements of a building, whether residential or commercial, but that from conception to demolition consideration has been taken to maximize living conditions while minimizing the building’s overall negative effect on the environment.
As with conventional building, many areas of sustainable building have been defined by building standards and regulations organizations, which can be either governmental or private initiatives. These standards organizations help control and guide the direction of sustainable building projects, which usually have a very high level of complexity. A good list of these organizations worldwide can be found from the below link:
The large range of sustainable building standards and regulation organizations found throughout the world implies a variety of approaches, however the primary areas for sustainable building include:
- Site location
- Design and construction
- Indoor environmental quality
- Energy efficiency
- Water usage
- Waste reduction
- Optimizing building operations and maintenance
- Retrofitting older buildings
When planning for a sustainable building, the site location is usually the first element to consider because it will determine the conditions for the construction of the building, e.g., access to water, renewable energy possibilities, existing infrastructures and communities, etc. In this sense the site and building design need to work holistically with the objective of minimizing the building’s total environmental impact over its lifecycle, including construction, habitation and demolition.
The design and construction of sustainable buildings focuses on environmental efficiency including:
- Construction methods
- E.g., Using green roofing, eco-friendly materials, modern insulation methods
- Construction materials
- Energy systems and usage
- Water management and usage
- Waste management processes
The goal is to maximize a building’s form and function with regard to the way its components integrate, or synergize, with each other and the surrounding environment.
The materials used should include as many of the following properties as possible:
- Locally obtained
- Minimal transportation required
These materials can be organic, e.g., stone, clay, wood, hay, recycled paper, etc., or they can be inorganic, e.g., recycled industrial goods, demolition debris, etc.
Beyond incorporating sustainable materials, the design needs to include variables such as:
- Air quality
- Energy efficiency
- Structural integrity
- Maintenance efficiency
Indoor Environmental Quality (IEQ)
Indoor environmental quality involves all the conditions associated with residing inside a building, whether it be a sustainable building or not. This includes:
- Thermal comfort
- Acoustical quality
- Visual comfort
- Indoor Air Quality (IAQ)
These qualities are taken into consideration by a number of organizations and building standards around the world. Of higher priority is Thermal Comfort and Indoor Air Quality, both of which have the most immediate impact on an occupant’s well-being. Indoor air quality includes:
- Control of pollutants
- This involves controlling the effects of air related elements such as
- Gases, e.g., radon, carbon dioxide, carbon monoxide, ozone
- Air born particles, e.g., dust, asbestos,
- Air born microbes, e.g., molds, legionella
- Volatile organic compounds, e.g., paints, cleaning fluids, building materials
- HVAC design
- This involves initiatives by the Heating Ventilating and Cooling (HVAC) industry to better regulate indoor air quality by use of air controlling technologies and procedures, which include:
- Indoor air refresh rates based on carbon dioxide levels
- The use of air filters for pollutants
- Moisture control
An example of how indoor air quality is rated can be seen from an initiative by The United States Environmental Protection Agency called “Indoor Air Plus”, which was developed to “help builders meet the growing consumer preference for homes with improved indoor air quality” . It includes topics on:
- Moisture Control
- Radon Control
- Pest Management
- Combustion Venting
- Building Materials
- Quality Assurance and Homeowner Education
Energy efficiency in sustainable building relates to how effective a building is at providing the year round energy requirements of the occupants while minimizing the negative effects of energy creation and usage, e.g., CO2 emissions and waste heat. It is generally one of the most expensive areas of sustainable building design. Principal areas of energy usage in a building are temperature control, ventilation, electricity and lighting. To effectively supply these variables, a building can incorporate a number of energy efficiency techniques that include:
- Includes insulation design and materials, windows
- Ventilation design
- Includes active and passive systems for air ventilation
- Passive solar design
- Includes combining a building’s design and construction with yearly variations in solar conditions that can effect temperature and lighting conditions
- Active solar and wind technologies
- E.g., solar panels, solar water heating, wind turbines, that create renewable electricity and hot water
- Lighting design and technologies
- Includes passive solar design, energy efficient lighting technologies, e.g., LED lamps
- Heat pumps
- For energy efficient heating
- Heat recycling
- Includes heat recovery from ventilation, hot water recycling from showers and dishwashers
- Thermal bridging
- Control of a building’s thermal pathways that conduct temperatures from hot to cold or vice versa where condensation can build up and cause damage to a building’s internal structure
When considering energy efficiency in a building there are many factors involved including the building purpose and climate conditions. Energy efficiency in buildings can run from inefficient all the way to an energy plus classification, where the building actually produces more energy than it consumes. Many countries have energy ratings to help classify a building’s energy efficiency. An example of this is the HERS Index in the U.S., which runs from 0 to 150, where 0 is the most energy efficient building and is classified as having a no net purchase of energy.
There is a class of building termed “passive” because the design and function of such a building allow for achieving the building’s energy requirements passively, i.e., heating and cooling is controlled through use of super insulation, triple glazed windows, air tight construction and a ventilation system, and electricity is controlled through solar and/or wind power. The passive building concept was developed in Germany and Sweden. Related terms include passive building, passive house and Passivhaus. For more information, see the below links.
As with every aspect of sustainable building, the goal of water usage is to maximize efficiency while minimizing adverse effects on the environment. Achieving this depends on many factors such as the building type, e.g., residential, commercial, manufacturing, etc, the climactic conditions, e.g., temperature and rainfall, and geological conditions, e.g., ground water supplies, which must be cared for. Ways of being efficient with water include (from Wikipedia article ):
- Water metering
- Keeps track of water usage
- From the water source
- At the point of usage
- Water meters can reduce water usage by 20% to 40% 
- Low-flow shower heads
- Low-flush toilets and composting toilets
- These have a dramatic impact in the developed world, as conventional Western toilets use large volumes of water
- Dual flush toilets created by Caroma includes two buttons or handles to flush different levels of water
- Dual flush toilets use up to 67% less water than conventional toilets
- Saline water (sea water) or rain water can be used for flushing toilets
- Faucet aerators, which break water flow into fine droplets to maintain "wetting effectiveness" while using less water
- An additional benefit is that they reduce splashing while washing hands and dishes
- Wastewater reuse or recycling systems, allowing:
- Reuse of graywater for flushing toilets or watering gardens
- Recycling of wastewater through purification at a water treatment plant. See also Wastewater - Reuse
- Rainwater harvesting
- High-efficiency clothes washers
- Weather-based irrigation controllers
- Garden hose nozzles that shut off water when it is not being used, instead of letting a hose run
- Using low flow taps in wash basins
- Automatic faucet
- Is a water conservation faucet that eliminates water waste at the faucet. It automates the use of faucets without the using of hands.
- Water can be conserved by landscaping with native plants
- Changing behavior, such as shortening showers and not running the faucet while brushing teeth.
For sustainable building, waste falls into two main categories, waste from construction and demolition (C&D), and waste from habitation.
- Waste from construction and demolition
- Building construction and demolition creates lots of waste, which in the U.S. can be as much as 40% of the country’s total solid waste output.
- Construction waste includes :
- Landscape and land clearing debris (green wood materials)
- Asphalt pavement
- Gravel and aggregate products
- Masonry scrap and rubble (brick, concrete masonry, stone)
- Metals (ferrous and nonferrous)
- Clean wood (dimensional lumber, sheet goods, millwork, scrap, pallets)
- Plastics (films, containers, PVC products, polyethylene products)
- Asphalt / bituminous roofing
- Insulation materials
- Glass (un-tempered)
- Door and window assemblies
- Carpet and carpet pad
- Fibrous acoustic materials
- Ceiling tiles
- Plumbing fixtures and equipment
- Mechanical equipment
- Lighting fixtures and electrical components
- Cardboard packing and packaging
- Traditionally most waste from construction and demolition ends up in landfills, and a main goal is to reduce this
- With proper waste management processes, up to 90% of waste from building construction and demolition can be recycled and not end up in a landfill
- Construction waste management processes include :
- Identifying waste type
- Construction Waste: Waste materials generated by construction activities, such as scrap, damaged or spoiled materials, temporary and expendable construction materials, and aids that are not included in the finished project, packaging materials, and waste generated by the workforce.
- Demolition Debris: Waste resulting from removing a building from the site by wrecking.
- Land Clearing Debris: Vegetative waste materials removed from a site.
- Disposal (or Landfilling, or Landfill Disposal): Depositing materials in a solid waste disposal facility licensed for the subject materials (in this case, C&D materials).
- Recycling: Introducing a material into some process for remanufacture into a new product, which may be the same or similar product or a completely different type of product.
- Salvage: Recovery of components, products, or materials for the purpose of reusing them for the same or similar purposes as their original use.
- Reuse: The subsequent use of a material, product, or component upon salvage.
- Deconstruction: The systematic disassembly of a building, generally in the reverse order of construction, in an economical and safe fashion, for the purposes of preserving materials for their reuse.
- Source Separation (or Segregation): Keeping materials separated by type from the time they become scrap or waste until the time they are salvaged or recycled.
- Off-Site Separation: Sorting and separating commingled waste at a location other than the construction jobsite, that location having been established for the purpose of recycling.
- Commingled: Materials of varied types deposited into the same receptacle or pile, or mixed together during demolition.
- Waste from habitation
- Waste that’s created from building occupancy includes:
- Radon, carbon dioxide, carbon monoxide, ozone
- Waste water, cleaning/industrial fluids
- Organic and inorganic solids
- Traditionally, solid waste has posed the greatest challenge, where handling it involves coordinating urban waste management projects with individual behavior.
- The hierarchy of solid waste management approaches is :
- Reduction: using fewer disposable goods
- Reuse: using items again after their initial consumer use is past
- Recovery (recycling and composting): recapturing the material or energy value of the item
- Incineration: burning waste, which can include recovering energy through heat
- Landfill: dumping waste at designated waste disposal areas (the last option)
Optimizing Building Operations and Maintenance
With sustainable building, much emphasis is placed on construction and demolition (C&D), however an equally important area is building operations and maintenance. This is where every day practices can result in either a positive or negative net outcome regarding fulfilling the objectives of a sustainable building. Some recommended practices for this include :
- Train building occupants, facilities managers, and maintenance staff in sustainability principles and methods
- Employ environmentally preferable landscaping practices
- Purchase cleaning products and supplies that are resource-efficient and non-toxic
- Use automated monitors and controls for energy, water, waste, temperature, moisture, and ventilation monitors and controls
- Reduce waste through source reduction and recycling
- Support practices that encourage sustainable transportation or minimize travel
Retrofitting Older Buildings
With advances in sustainable building practices comes developments in techniques to retrofit older buildings with sustainable properties. This involves analyzing an older building to determine what areas can be improved to increase its sustainability rating. Areas that can be analyzed and improved include , , :
- Replacing windows and doors with energy efficient models
- Sealing and caulking existing windows and doors
- Tightening existing ductwork
- State-of-the-art insulation for walls, floors and roofs
- Using insulation and enclosed air spaces to enhance in-house temperature stability
- Cooling the attic with a heat reflective roof and vents
- The use of awnings, trellises, arbors and "pods" to shield a house from summer sun
- Replacing out-dated furnaces and water heaters with current energy-efficient models (HVAC control)
- Solar thermal collectors for heating and hot water
- Solar powered water pre-heaters
- Solar panels and wind turbines for electricity
- Landscaping practices that shelter a house from weather extremes
Links to some Sustainable Building Codes and Certification Standards
- http://www.epa.gov/iaplus01/about.html United States Environmental Protection Agency
- http://en.wikipedia.org/wiki/Water_conservation#Household_applications Wikipedia
- http://www.epa.gov/owow/NPS/nps-conserve.html United States Environmental Protection Agency
- http://www.wbdg.org/resources/cwmgmt.php Whole Building Design Guide
- http://ohioline.osu.edu/cd-fact/0106.html Ohio State University Fact Sheet
- http://www.wbdg.org/design/optimize_om.php Whole Building Design Guide
- http://sustainability-teaching-farm.com/content/85 The Broadened Horizons Organic Farm
- http://meadeconstructionllc.com/green-retrofitting/ Meade Construction LLC
- http://greensource.construction.com/news/2010/100407BuildingStar.asp Green Source