Resources: Glossary

2x4 and 2x6 Standard Framing (16" or 24" oc)
The 2x4 and 2x6 frame wall at 16" oc are standard framing systems. 2x6 at 16" or 24" oc is often used in residential construction in Minnesota to meet current building codes and performance standards. This wall system includes siding, oriented strand board (OSB) sheathing, 2x6 wood studs, single bottom plate, double top plate, R-19 fiberglass insulation, vapor retarder, and _ inch gypsum board. The advantages of this method include familiarity by the trades, easily available products, and the ability to achieve a relatively high R-value. The disadvantages of this system include the use of more material than necessary to meet engineering requirements, and the additional time required for framing (as compared to some other systems). For cost and environmental implications see the Cost and Life Cycle Thinking below.

2x6 Advanced Framing
PATH Technologies, "Advanced Framing Technologies: Optimum Value Engineering (OVE)" Toolbase Services, www.pathnet.org.

The 2x6 advanced framing wall system is an adaptation of standard frame construction to reduce cost and material consumption while improving performance. The 2x6 frame is typically spaced at 19.2" (1/5 of an 8' sheet) or 24" on center (roof framing spacing is already typically 24"). This strategy can be combined with modular layout and single top plate for added economy, but can also be used independently. Some insulation manufacturers do not make insulation for 19.2" spaced framing, so using this spacing in an insulated wall may require changing the type or brand of insulation. Building to a 24" module and using 24" on center wall and floor framing can maximize framing material cost savings. In addition, advanced framing is combined with a variety of construction strategies to further reduce cost and material consumption, including the use of open corner framing and strategies to reduce the size and number of headers for bearing and non-bearing partitions.

The advantages of advanced framing are that it reduces the amount of lumber and lowers material and labor costs while improving energy performance. Wider stud spacing reduces heat loss and increases the amount of insulation in the wall. Significant amounts of lumber can be removed from the wall and floor framing, although the need for thicker decking, cladding and finish materials may partially reduce the savings. In general, simpler plans designed on a 2' module are much more likely to result in savings. The disadvantages of the system are that additional time may be required for framers who are unfamiliar with the techniques and additional planning may be needed for design and construction. In addition, floor decking, cladding and interior finish materials need to be sized to span the added dimension without undesirable deflection. In high-wind and earthquake zones, 16" on center framing may be necessary to meet loads. For cost and environmental implications see the Cost and Life Cycle Thinking below.

Accessory (apartment)
A small apartment or studio located in house built with the intention of being rented to provide income for the support of the mortgage.

ACQ treated wood
Alkaline Copper Quanternany (ACQ) is a non-arsenic wood preservative. ACQ wood is wood or lumber treated with ACQ as a preservative.

AFUE
Annualized Fuel Utilization Efficiency (AFUE): The AFUE is the measure of efficiency for furnaces on a 0 to 100 scale with 100 being the best performance possible. A point on the scale equals 1% of efficiency; therefore an 80 AFUE furnace is 80% efficient. A 78 AFUE is the government minimum and 97 AFUE is the current high rating.

Aluminum
Introduced in the 1940's aluminum siding once enjoyed a fair share of the non-wood siding market. Soon after introduction it was offered in a variety of enameled colors. It was low maintenance, resistant to corrosion or deterioration, lightweight, durable, and needed minimal repainting. Aluminum siding's popularity declined after the introduction of vinyl siding, which is cheaper and unlike aluminum siding is not prone to do denting. Today, some aluminum and steel sidings have a PVC color protective coating which improves durability, offers greater color selection. These coatings increase the negative environmental impacts of the material by introducing PVCs into the product, and may affect recycling of the siding at the end of life.

Assemblies
The assemblies scale focuses on construction systems for foundations, roofs, walls, and floors.

Backdrafting
A backdraft is reverse flow of air down a chimney or exhaust pipe caused by a low pressure in or around the combustion chamber. A backdraft can cause the build up of exhaust fumes, such as carbon monoxide and carbon dioxide, in the home. Carbon monoxide poising in low concentrations can cause headaches and in high concentration death.

Basement
A basement is the most common foundation in Minnesota's cold weather climate. Since foundation walls must extend 3.5 to 5.0 feet below grade, the addition few feet of wall and a concrete slab can provide an entire level of useable space. This additional space is usually regarded as a worthwhile trade-off for the additional cost. Basement walls can be concrete, concrete block, or wood. Walls must incorporate thermal and moisture control. Chronic moisture and potential health problems from mold in basements require reliable drainage and waterproofing systems that may increase costs above conventional practice. A typical windowless basement is suitable for mechanical equipment, laundry, and storage. Often living spaces and bedrooms are placed in basements as well. If there is an intention to use a basement for living space, the design must address indoor air quality, moisture control, daylighting, ventilation, and egress.

Basement concrete block (Concrete Masonry Units - CMU)
Concrete masonry units are an efficient use of cement and provide a strong and durable structure. They have a high embodied energy because of the heat required to process them. They can be insulated and can provide a heat-sink component to interior design. They require waterproofing, some type of internal or external insulation, and, depending on the height of the building, may require additional reinforcement, such as rebar. The more materials required for the installation, the higher the environmental impact.

Basement poured concrete
Concrete in any form has a higher level of environmental impact than wood construction. Inclusion of materials such as fly ash and blast furnace slag reduce the need for cement, thereby reducing CO2 emissions and related air and water pollution levels. A poured basement foundation, with installed reinforcement provides a stable, safe structural construction with higher fire resistance and the potential for better moisture infiltration prevention. However, a high quality waterproofing system is recommended (petroleum-based in most cases) and insulation is necessary to provide an energy efficient installation. All these materials, combined in an assembly, create a highly impactful assembly.

Biodiversity
The diversity or variety of plant and animal species living in an area

Blower door test
A test performed on a house to determine its air tightness. The house is pressurized using a blower door, actually an insert that fits into a door opening with a blower and pressure gauges, the rate of air pressure loss is used to determine the leak rate and the air tightness of the structure.

Brick
A brick is a hand sized rectangular building unit, roughly 2 1/4 x 3 3/4 x 8 inches, made from clay and hardened by heat, usually at high temperatures in a kiln/oven. Brick has been used for millennia as a building material. Bricks can be used as a load-bearing wall in residential construction, but this type of construction is rare today due to the intensity of labor, energy codes and expense. More commonly today, brick is applied as a veneer over other wall assemblies. Since brick is a relatively expensive cladding option for residential construction, it is often used in a decorative manner (as a wainscoting or only on the front facade of a house). Brick is very durable and requires low maintenance.

Certified sustainable yield wood
Certified sustainable yield wood comes from a forest managed with sustainable yield practices. The sustainable yield of an area (forest) is established by determining, how much and what types of woods can come out of a given area over a period of time without negative impact on the forest. This determined yield sets the limits of the harvest in order to sustain the forest indefinitely.

Chromated copper arsenate (CCA)
Chromated copper arsenate (CCA) is a wood preservative and pesticide. Wood treated with CCA is readily identified by its green color. The wood industry has voluntarily withdrawn the use of CCA for residential use.

Cisterns
A large tank or reservoirs for storing rainwater.

Coating
The broader grouping of liquid substances applied for protection or decoration, including paints, varnishes, stains, and lacquers. All these products are generally made from pigments, thinners, resins and additives used to enhance specific characteristics.

Components
The components scale is comprised of materials, finishes, and equipment. Materials and finishes examines individual components of construction systems. Equipment encompasses heating, cooling, and plumbing systems.

Crawl Space
Crawl spaces are not a common foundation type in Minnesota; yet, they may provide a viable and affordable alternative. Crawl space can be less expensive than a basement because footings only extend to frost depth and the slab can be replaced with a durable moisture barrier. However, a crawl space achieves the desired raised floor appearance and feeling of warmth. Depending on the height, crawl spaces can be accessible and contain mechanical equipment, ducts, pipes, and wiring. Traditionally, crawl spaces were vented with outside air to remove moisture. This requires insulation in the crawl space ceiling and means pipes and ducts are open to outside air. Research has shown that in most climates, vented crawl spaces are not effective in terms of energy use and moisture control. Therefore, an unvented crawl space is recommended. An air-tight moisture barrier on the entire floor and walls in addition to wall insulation is essential. The wall structure may be concrete, concrete block, wood, or a pile-type foundation. A shallow frost-protected foundation with horizontally extended insulation can be used to reduce the footing depth of a crawl space. To minimize cost and material use without compromising the quality of above ground space, a crawl space on a low cost pile foundation may be an optimal solution for affordable housing. Piles could be placed at the appropriate depth and filled with concrete. The wood floor would then be supported on steel beams connecting the grid work of these pipes. However, a thermal perimeter skirt is required to maintain a conditioned crawl space.

Daylighting
Daylighting is the use of daylight to provide illumination for interior spaces, thus reducing the dependence on electric light.

Direct vent gas fireplaces
A fireplace, furnace, water heater which vents exhaust gases directly to the exterior.

Double Glazing Low-E (high solar gain)
This window unit has the following characteristics, U-factor = 0.36, SHGC = 0.52, VT = 0.53, and a wood/vinyl frame. Passive solar strategies rely on maximizing solar gain, in cold climates it is important to balance heat loss and gain through the window.

Drain tiles
Drain tiles are perforated pipes placed near the footing of a foundation to facilitate water drainage. They have also been used by farmers to drain low lying areas of crop fields.

Drip irrigation
A system of irrigation that supplies water in a slow, even amount through under ground or near surface pipes/tubes. Drip irrigation reduces water loss due to evaporation and the potential for soil erosion due to runoff.

Ecological systems
Sometimes referred as ecosystems, ecological systems are natural systems of interrelated and interdependent elements. A forest is an ecological system in which trees, birds, and animals share a joint habitat.

Energy factor
An energy factor (EF) is the measure of efficiency for water heaters.

Energy recovery ventilator (ERV)
An energy recovery ventilator is similar to a heat recovery ventilator; it is used to capture heat from exhaust air and pre-heat incoming fresh air. ERVs have the added capacity of injecting or extracting humidity, which is beneficial in cooling dominated climates.

ENERGY STAR
Energy Star is a program of the U.S. Environmental Protection Agency and the Department of Energy to encourage the development and purchase of energy efficient building components and appliances.

Engineered lumber
Manufactured building materials and components made from wood or wood pulp used in building. Including sheathings such as plywood, and osb panels, and structural elements such glulam beams, wood I-joist and wood trusses.

Erosion
A lose of soil caused by wind and water.

Expandable foam and caulk
Sealant and caulks that expand, like shaving cream, and are used as air sealant and insulations for small wholes. Non-expandable foam is used around windows and doors to air seal gaps between the frame and the wall.

Exterior Gypsum Sheathing
Exterior gypsum sheathing is a paper-faced gypsum sheathing board used as a substrate for exterior claddings. It has a noncombustible core, composed essentially of gypsum and is faced paper on its back, front and edges. It is manufactured with either a square or a tongue-and-groove edge. A wide range of exterior grades are manufactured varying from non-water resistant to water repellent.

Flash and seal
Flash and sealing refers to the installation of flashing and sealants, such as caulks, to prevent moisture from entering structural cavities. It is part of the weatherization of a home or building.

Fiber-cement board
Current fiber-cement products are direct descendants of asbestos-cement building products that were widely used until the 1970's, but contain no asbestos. Fiber-cement products are formed from a mixture of cement and wood fiber (which constitutes 8-10% of the material). Fiber-cement board products are typically 5/16" thick. . Fiber cement plank and lap siding is available in a variety of widths and finish textures. Panels are available in 4' x 8', 9', or 10' sheets. Some fiber-cement panel manufacturers offer a stucco finish in addition to smooth or wood-grain textures. Several fiber-cement manufacturers now offer accessory trim, soffit, and fascia elements. Fiber cement materials can be worked with woodworking tools, and should be finished with an alkali-resistant paint, although some can be used unpainted if handled carefully to avoid scratching. Most fiber-cement products come with a 50-year manufacturer's warranty, due to the relative newness of these products true longevity is unknown. It is expected that fiber-cement products will need less frequent repainting than wood products, since it expands and contracts less with fluctuations in moisture.

Formaldehyde-free materials
Urea-formaldehyde is a volatile organic compound used in glues and resins in the manufacture of some wood products. Exposure to formaldehyde can have adverse impacts on the human respiratory system and may be an asthma trigger. Formaldehyde-free materials are materials that do not contain these compounds. For more information see www.epa.gov/iaq/formalde.html

Garden Basement
A garden basement is not common in Minnesota, but has advantages. Since foundation walls must extend 3.5 to 5.0 feet below grade, a garden basement can take full advantage of this fact by providing living space in a floor partially below grade without unnecessarily increase the amount of concrete required and limiting the excavation. The below grade portion of the walls can be concrete, concrete block, or wood. Above grade walls can utilize whatever wall system is being used in the rest of the house. Reliable drainage and waterproofing systems may increase costs above conventional practice but are essential. Installation of windows in the above grade portion of the floor follows conventional practice for the wall construction system being used. A garden basement is typical built with the intention of using as living space. The design and construction must address all the issues associated with a "habitable basement" including indoor air quality, moisture control, daylighting, ventilation, and egress.

Glu-laminated (2x12) wood floor construction with solid plank decking
Glulam beams have superior strength and stiffness and are available in a range of grades and sizes. Framing-grade glulam beams can be used in a wide range of concealed floor framing applications. When the beams are exposed, such as second story floor framing where the glulam is exposed to the floor below, an architectural-grade beam combines the strength of glulam with the warmth and beauty of wood. This type of construction may be left exposed because glu-lam members are more aesthetically attractive than truss or I-joist construction. Methods to conceal ductwork and electrical components ensure that less materials are used for enclosure, also reducing the possibility that moisture might build up in undiscovered locations. (APA website www.apawood.org/level_b.cfm?content=app_bas_floor ) Using solid wood planking requires less efficient use of lumber and larger, more resourceful trees are used than when engineered wood products are used. There is more fluctuation in the wood products because humidity plays a greater role in expansion and contraction in solid wood than in engineered products.

Graywater systems
Graywater is any water that has been used in the home, except water from toilets. Dish, shower, sink and laundry water comprise 50-80% of residential "waste" water. Graywater systems collect and hold water for use in landscape irrigation and for flushing of toilets.

Ground coupled heat pumps
A ground coupled heat pump is a combined heating, cooling, and hot water system, and is also referred to as geothermal. Ground coupled heat pumps exploit the consistent temperature of the earth as a heat source and sink. A loop of liquid is connected to a compressor, which expels or absorbs heat depending on the season.

Habitat
The environment in which a plant or animal naturally grows or lives.

Hardboard
Hardboard siding products are produced from low-grade trees, which are turned into wood chips, fiberized, mixed with phenol formaldehyde (PF), paraffin, and alum, then compressed and baked at a high temperature. Hardboard products need to be painted to maintain moisture protection.

Heat recovery ventilator (HRV)
A heat recovery ventilator is device which transfers heat between exhaust air and incoming fresh air. Saving energy regardless of the season by pre-heating or pre-cooling the incoming air.

High Efficiency Particulate Air (HEPA) filters
A High Efficiency Particulate Air or HEPA filter is typically a throwaway dry media filter which removes 99.97% of particulate matter from the air bigger then 0.3 micrometers in diameter.

HVAC
HVAC is the acronym of Heating, Ventilation, and Air Conditioning, and in homes generally refers to the furnace, fresh air supply, and air conditioner.

Indoor environmental quality (IEQ)
Indoor environmental quality refers to the ability of a place to support and enhance human comfort and well-being. The factors involved are lighting, air quality, access to views, and thermal comfort.

Infiltration system
A system that collects and brings storm water runoff from impervious surfaces (e.g roofs, paved surfaces) to a pervious are such as a rain garden where it is allowed to seep into the ground.

Infrastructure
The public works of a country, state, or region, including roads, electricity, water, gas, sewer, and storm water services.

Insulated Concrete Forms (ICF)
Even though this system relies on poured concrete, with its attendant high environmental impacts due to cement and aggregate use in concrete, using stay-in-place insulating formwork in foundation walls (ICF) improves overall environmental performance for basement construction. Use of these forms can reduce the amount of concrete needed and provides insulation value as well. There are impacts associated with the rigid insulation, but in a good construction, there will be insulation used at the foundations anyway, so it is not adding another material.

Integrated pest management systems
Integrated pest management is an ecological approach to pest management utilizing plants and animal species as a means of controlling invasive and unwanted species, rather then relying on chemical insecticides.

Life Cycle Thinking
Life Cycle Thinking is evaluation and interpretation of the environmental aspects and potential impacts throughout a product's life from raw materials acquisition through production, use and disposal. The general categories of environmental impacts for consideration include resource use, human health, and ecological consequences. For the purposes of this project, the evaluations are made using current tools such as BEES and ATHENA. These tools provide basic impacts in the areas of global warming potential, air pollution indices, water pollution and use indices, primary energy use, material resource use, and solid waste contributions. Comparisons of impacts are within the assemblies identified, based on the aggregate of individual components. Results from individual product analyses are only used when assembly information is unavailable.

Livable Basement
Indoor air quality issues in basements are a particular concern since the space is located below grade where it is more susceptible to water, moisture, and soil gases which can negatively impact air quality and habitability. Providing and maintaining a healthy indoor environment in the basement includes strategies for design, construction, and occupation. Design and construction strategies include water managed foundations that keep rain away from the foundation wall perimeter (including strategies above grade such as gutters, overhangs, down spouts, and grading to slope away from foundations) and numerous construction strategies to optimize groundwater drainage away from the sub-grade foundation walls (from grading to drainage, damp proofing, and detailing of the foundation walls, footings, and concrete slab). In addition, soil gas construction methods and ventilation systems should be addresses to control possible admission of radon, water vapor, herbicides, methane, or other toxins out of the basement.

In addition, a livable basement should include windows for sufficient daylighting, fresh air, and egress. While design and construction strategies can help to minimize possible health related issues in basements, the homeowner needs to maintain a healthy environment during occupation. Homeowners should eliminate or minimize activities and materials that can cause indoor air quality problems. Since moisture is a great concern in basements, it is especially critical to eliminating or minimizing porous materials in basements. This includes carpet and porous fabrics that may provide possible "sinks" for moisture that can facilitate growth of mold and mildew and subsequent indoor air quality issues.

Livability
Livability refers to the suitability of a place for health and safe human occupation or habitation.

Live-work
A house with an office or studio attached or within that serves solely as a place of work for the home owner. The work space typically a business entrance, independent from the homes entrance.

Low maintenance landscapes
Landscapes that require little or no additional watering, weeding, pruning, cutting/trimming, or other maintenance.

Low-VOC
Low-VOC is a low level of volatile organic compounds.

Massing
Massing refers to the overall size, shape, and volume of a building.

Master plan
A comprehensive plan for a neighborhood or region intended to set goals and guide development. Goals may include economic development, transit, mix of house types, density levels, and may address issues of aesthetics and sustainability.

Microclimate
Microclimate is a highly localized climate that is different from general climate conditions. Microclimates often occur around builds, or on one side of a building, due to blocking of winds and the trapping of heat form the sun.

Mixed-use
Mixed-use and mixed use development locates residences, offices, retail establishments, and commercial functions within close proximity to one another, usually walking distance, rather than separated. Mixed use can be vertical with shops and offices below housing in a multi-floor building, or horizontal with house and shops detached from each other.

Native plants
Native plants are particularly adapted to a region's geography, hydrology, and climate since they have evolved and adapted over thousands of years to a particular area.

Natural ventilation
Natural ventilation or passive cooling utilizes seasonal breezes and air movement to cool a room or house.

Neighborhood
The neighborhood scale focuses on issues of community development including lot size, development density, and infrastructure.

NFRC
National Fenestration Rating Council (NFRC) is a non-profit, public/private organization created by the window, door and skylight industry. It is comprised of manufacturers, suppliers, builders, architects and designers, specifiers, code officials, utilities and government agencies. NFRC provides consistent ratings on window, door and skylight products. www.nfrc.org

non-HCFC refrigerants
Hydrochlorofluorocarbons are a group of ozone depleting chemical currently being phased out of use with 100% phase out by 2030.

Nontoxic or low-toxicity materials
Nontoxic or low-toxicity materials are materials that have no or low impact on human heatlh.

OSB
ORIENTED STRAND BOARD (OSB) is a relatively new sheathing material that is replacing plywood. It is manufactured from small diameter, fast growing trees. Unlike waferboard, it is manufactured with the fibers of the wood oriented to provide maximum strength. For quality control OSB panels should bear a stamp of the Structural Board Association (SBA) or TECO identifying them as structural rated sheathing. OSB should not be used as siding or in other applications where it will be subject to prolonged exposure to moisture.

Overheated period
The overheated period refers to the time of year when it is hotter than what is normal considered comfortable for people. In Minnesota this period is typically from June thru August and early September.

Paint
A mixture of liquid and solid materials, usually opaque, that forms a thick liquid substance which can be applied and which dries to a hard dense surface. Generally it does not sink into the substrate (esp. wood or fibers.).

Passive solar
Passive solar heating utilizes the free energy of the sun to heat a house during the under heated period of the year. Passive solar systems do not really on mechanical devices to harvest the sun's power; they are simple systems of south facing glazing to collect radiant energy and thermal mass to store radiant energy.

Permeable
A material that permits a liquid (or gas) to pass through, the ground is permeable to water, a concrete sidewalk is not.

Permanent Wood Foundation (PWF)
The perceived durability and efficiency of wood foundations have suffered from inadequate and poorly constructed examples. Because wood is a renewable resource, it is assumed to have lower environmental effects. To be used in a foundation, wood must be treated with significant chemicals to preserve it, pressure-preservative treated with Ammoniacal (ACA) or Ammoniacal Copper Zinc Arsenate (ACZA.) These chemicals have negative impacts during production and application to wood members and may leach into the surrounding groundwater if not adequately protected. Waterproofing systems that ensure a moisture-resistant installation and good insulation for improved energy efficiency increase the life cycle term for wood foundations, although petroleum-based. http://muextension.missouri.edu/xplor/agguides/forestry/g05510.htm

Photovoltaic
Photovoltaic (PV) and photovoltaic systems convert the radiant energy of the sun into electricity. PV can have battery storage or can be connected directly to the grid (the power company). If grid connected, during power generation the electric meter spins backwards as power is fed onto the it.

Pigment
The solid material which adds color to another material it's added to.

Plans
A set of drawings, specifically referring to a drawing which shows the layout of the rooms and functions of a home.

Plywood
Plywood is made by gluing together thin plies (veneers) of softwood or hardwood. There is always an odd number of veneers and the direction of each ply is at a right angle to the adjacent plies, this gives the material it's strength. The more plies, the greater the strength of the plywood. Plywood is graded for exterior or interior use depending upon the water resistance of the glue used to stick the plies together. Code letters shows this grading on each sheet.

Prefabricated components
Prefabricated component are factory assembled parts, such as walls, roof trusses, and some plumbing, that arrive on the building site ready to install. Manufacturing over site built components has several advantages including quality control, reduced cost and reduced material resources. The disadvantages are a lack of customization, and the potential for long distance shipping of components.

Programmable set-back thermostat
An electronic thermostat which can be programmed with a schedule to automatically set back the temperature when occupants are not at home, or during the night time hours.

R value
R-value is a measure of a materials resistance to heat flow. The higher the R-value, the greater the materials insulating properties, and the better it is at preventing heat loss. U-value is the inverse of the R-value.

Radon infiltration
Radon is a naturally occurring radioactive gas, and the second leading cause of lung cancer in United States. (U.S. Environmental Protection Agency). Radon infiltration is the leaking of radon into the house through the basement. For more information see www.epa.gov/radon/

Rain gardens
A rain garden is a bowl-shaped gardens designed to collect and absorb storm water runoff from impervious surfaces such as roofs and parking lots. They are often planted with perennial native plants, which thrive in moist soils. Most rain gardens are designed to hold water only for a few hours. and do not have standing water.

Rainwater catchment system
A system of gutters, pipes, and tanks that captures rain water from a roof, or low lying area. The water is stored and can be used for irrigation or as part of a gray water system.

SEER
Seasonal Energy Efficiency Rating (SEER) is a measure of cooling efficiency for air conditioning units. The higher the SEER rating number, the more energy efficient the unit is. Current federal guidelines stipulate 10 as the minimum. Energy Star rated units must have a rating of 13 or higher.

Sections
A drawing showing a vertical cutaway or view through a house.

Siting
The placement and orientation of a structure on the land, often to take advantage of the benefits of a particular site - such as views, natural ventilation, passive heating, or daylighting, while avoiding challenges such as poor soil or drainage conditions.

Slab-on-grade
A slab-on-grade foundation is often the least expensive foundation choice. A conventional slab foundation in Minnesota requires a foundation wall and footing extending below frost depth. Rigid insulation is placed vertically inside or outside the stem wall and/or horizontally beneath the slab edge. An alternative that saves material and cost is a shallow frost-protected foundation with rigid insulation extending horizontally out from the slab edge. The main drawback of a slab-on-grade foundation is that many people perceive this option as a lower quality foundation type. In Minnesota, a concrete slab is often thought of as a basement or garage floor that is harder and colder than a wood floor. A slab is typically built less than a foot above the surrounding grade, which can reduce the street presence of the house as compared to surrounding houses with basements. A wood floor raised above grade may be more appropriate in an inner city neighborhood to respond to the scale and street elevation of neighboring houses. Other issues with slab-on-grade foundations include the need to place all utility and storage functions above grade, and the inaccessibility of ducts, pipes and wires below the slab.

Slab/stem
Again, this system requires less material than a traditional basement configuration because it provides less livable square footage below ground. Comparison of below and above-grade construction, depending on the type of above-grade system selected, will tip the balance on environmental impacts one way or the other. For efficient and effective systems built above ground (ex. SIP or SEP), the environmental impacts are no more than for those built below grade.

Shallow frost
This system requires more concrete product, increased reinforcement and additional insulation to provide a fully developed foundation system. Access to the below-floor construction elements offers some benefit in accessibility to mechanical systems particularly, and this may improve overall performance of building systems. This improved ability to maintain the residence improves the long-term environmental impacts assessment, which is increased because of the additional materials, required in this system.

Silt fencing
A fence of fabric partially buried in the ground and stretched between support posts. The intention of a silt fence is to prevent soil from washing away, during a rain storm, for the duration of building construction.

Social and cultural factors
Factors relating to ethnicity, economic situation, or religious beliefs which impact patterns of living within a house.

Solar Heat Gain Coefficient (SHGC)
The SHGC is the fraction of incident solar radiation admitted through a window, both admitted through a window, both directly transmitted, and absorbed and subsequently released inward. SHGC is expressed as a number between 0 and 1. The lower a window's solar heat gain coefficient, the less solar heat it transmits.

Stains
A mixture of solid and liquid substance applied especially to wood that penetrates the surface and imparts a rich color. Opaque and semi-transparent are available, in addition to the traditional transparent application.

Storm sewer
A network of sewer pipes to carry excess storm water away from streets, often draining into a nearby water body such as a lake or river.

Structural Engineered Panels (SEP)
The Structural Engineered Panel (SEP) wall system is composed of a solid 1 1/8" to 1 _" oriented strand board (OSB) panel. The system must connect with the foundation system in such a manner to support the wall and provide shear strength. A "Pressure Equalized Rain Screen Insulated Structure Technique" (PERSIST) insulation system is applied to the exterior before applying the siding. The factory-sanded OSB panel serves as the interior finish. This surface may be painted, stained or sprayed with a drywall finish material. The advantages of this system include a tight building envelope, elimination of dimensional lumber, and a wall assembly, which saves fabrication time since the panels are precut. The disadvantages of the system include the lack of familiarity of the system for the trades; lack of wall cavities for plumbing, electrical, and ducts; and possible volatile organic compound (VOC) off-gassing from some types of OSB and insulations. For cost and environmental implications see the Cost and Life Cycle Thinking below.

Structural Insulated Panels (SIP)
The Structural Insulated Panel (SIP) wall system is a factory made wall sections, which arrives on the building site pre-assembled and ready for installation. Although variations exist, SIPs are constructed from two sheets of oriented strand board (OSB) or plywood adhered to a rigid foam core of insulation. The OSB panels are typically _ inch thick, while the rigid insulation board dimensions typically vary from 4-8", depending on the climate and performance requirements. A weather barrier is applied to the exterior beneath before the siding is applied. Gypsum board is typically installed over the interior surface of the OSB. SIPs are capable of supporting typical loads for bearing walls, floors and roofs. They can provide both the primary structure and the envelope or they can be used with other structural systems such as post-and-beam construction to provide exterior envelope and insulation. Structural-insulated panels range in size from four by eight feet to 24 by eight feet, and are available in a variety of thickness and R-values. Typical R-value for a panel of six-inch depth is 22 compared to 19 for a typical two by six stud wall construction.

The advantages of this system include reduced time for the assembly, envelope tightness, and good energy performance. SIP systems reduce energy load in two primary ways. First, the panels provide continuous insulation resulting in an envelope with few thermal bridges where heat loss occurs. Second, the panels create an envelope with fewer seams; the building shell's tightness decreases infiltration. The air tightness of a SIP-constructed home can be as low as a third of typical new construction. These properties also increase thermal comfort of the home by eliminating cold spots and drafts. IAQ issues associated with SIP panels are minimal. The disadvantages include lack of trade familiarity with the system, higher cost compared to standard frame construction, and difficulty repairing errors in construction (such as repairs to the building envelope in the case of incorrectly located doors or fenestration openings). SIPs also have high-embodied energy from the manufacturing process. For cost and environmental implications see the Cost and Life Cycle Thinking below.

Stucco
Traditional stucco is a cement-based plaster (a mixture of Portland cement, lime, sand, and water) applied in three coats. Synthetic stucco, used in exterior insulation finish systems (EIFS), replaces the cement and lime found in traditional stucco with a polymer base. It is typically applied in two coats, with a thin fiberglass mesh embedded in the base coat. Hybrids of these two systems include traditional stucco with polymer additives and synthetic topcoats added over thick, traditional base coats. Due to the integral color in stucco's topcoat, painting is unnecessary. Stucco may be painted, but once it has been painted, that coating needs to be maintained to remain attractive. Stucco is long lasting and has low maintenance requirements. Moisture can be a problem with stucco, especially with synthetic stucco, which is less moisture-permeable than traditional stucco. Adequate flashing and drainage detailing are essential to the durability in any stucco wall finishing system.

Sub-floor
A sub-floor is the bottom most layer of a floor. The sub-floor is typically not seen, because it is hidden by the finished floor, which can be carpet, wood, or tile, etc.

Sustainable Forestry Initiative
www.aboutsfi.org/core.asp was developed by the American Forest & Paper Association (AF&PA), supported by major producers and manufacturers, with its own set of criteria and management practices.

Topography
Topography is the shape of the ground, its rise and fall or elevation changes.

Turf
A lawn or manicured landscape

U-value
The rate of heat loss is indicated in terms of the U-value of an assembly. The insulating value is indicated by the R-value which is the inverse of the U-value. The lower the U-value, the greater a window's resistance to heat flow and the better its insulating value.

Vehicle
The liquid portion of a finishing material consisting of the binder and volatile thinners as contrasted to the pigment or solid matter.

Visible Transmittance (VT)
The visible transmittance (VT) is an optical property that indicates the amount of visible light transmitted through the glass. VT is expressed as a number between 0 and 1. The higher the VT, the more daylight is transmitted. A high VT is desirable to maximize daylight.

Vinyl
Polyvinyl chloride (PVC) siding was first introduced in the 1950's, and since then has steadily increased its share of the residential siding market. "Today, more vinyl siding is produced than any other type of residential siding," (EBN, July/August 1997) and in 2003, over 4 billion square feet of vinyl siding were produced in the United States (Vinyl Siding Institute). Vinyl is inexpensive, easy to install, durable, and needs little maintenance. These attributes make vinyl products seem like the ideal material. However, chemicals used to manufacture PVC products, as well as those given off during its burning and disposal, have been proven hazardous to human and animal health, and the environment.

Volatile organic compounds (VOCs)
Volatile organic compounds (VOCs) are organic solvents, including paint additives, aerosol spray propellants, and many other building materials. VOCs effect human health and the environment.

Volume(s)
Volume refers to the three dimensional shape of the house or building, and the space enclosed.

Water heater heat pump
A water heater heat pump heats water by extracting energy from air or a ground.

Whole house fan
A large fan installed in the ceiling of the uppermost story of a house used to draw air warm air out of the house.

Wildlife corridors
The natural migratory pathways used by animals use to travel. Corridors can be traveled daily, as animals transverse an area looking for food, or used seasonally for migration.

Wood
Western Red Cedar, Redwood, Cypress, Northern White Cedar, and Eastern White Pine are the wood species most commonly used for wood siding. The most common types of wood siding are bevel lap siding, shiplap, board-and-batten, and shingles. Wood is a renewable building material and the forests in which it is grown provide diverse ecological habitats. It is energy-efficient to produce, very little waste is produced in its manufacture (since waste wood is often used for other manufactured wood products), and it is biodegradable. How forests are managed has a significant impact on the environment. Non-sustainable forestry practices result in soil erosion, loss of species diversity, and other environmental concerns.

Wood I-joist floor system with OSB decking
Use of horizontal I-beams from engineered wood products reduce virgin materials and waste disposed by burning or landfills. Joists are parallel to each other and a more efficient use of material when spaced 24 inches apart on center. In some cases, where more support is required, the joists may be closer together. I-joists provide consistent structural performance for residential applications. They can span long distances, offering flexibility. They are simple to install, are dimensionally stable, and are lightweight and easy to handle. When reasons of aesthetics require enclosure of exposed spaces, negative effects are increased because more materials are used, primarily those with higher embodied energy, such as gypsum board. Enclosed cavities also increase the potential for mold development affecting indoor air quality. (APA Website www.apawood.org/level_b.cfm?content=app_bas_floor )

Wood-resin Composite
Wood-resin composite siding is a manufactured wood based product. It is produce by mixing synthetic resins and wood dust, which are put into a die form press, and compressed under high temperatures. The resins reduce the risk of moisture damage. Wood-resin composite products can still be at risk of damage due to moisture, to prevent moisture damage most wood-resin composite siding is installed with ventilation spacers or furring strips behind the siding to permit drying.

Wood truss floor system with OSB decking
Prefabricated wood floor trusses improve efficiencies and quality control, and reduce on-site construction waste. However, because truss systems do not provide a generally acceptable aesthetic if left uncovered, they require an additional layer of material, for example a gypsum board ceiling or a lay-in acoustical tile ceiling, which increases the amount of material required for the full installation. More material, especially of higher embodied-energy products like gypsum board, increases the negative environmental impacts of the system. The addition of this enclosing layer, creating poorly ventilated areas prone to undiscovered leaks from plumbing or condensation, can also increase the negative impacts of the system, offsetting any value from efficient use of resources in the production of the trusses. Trusses are made from more virgin material, which does not usually come from certified sources ensuring more sustainable growth and harvesting; therefore they produce more negative environmental effects caused by chemical applications, clear-cutting, and poor production practices. Because they use virgin materials, there is more waste produced, which does go to produce engineered wood products.(From http://triplecrown.4t.com/articles/alpine-cfps.htm.)

Xeriscaping
A type of landscaping that uses plants with low and no water needs.

Yard
The yard scale examines site issues including landscaping and planting, storm water management, and general site planning.

Zero-VOC
Zero-VOC or no VOC is the absence of volatile organic compounds.