{"id":65,"date":"2009-01-03T14:57:41","date_gmt":"2009-01-03T14:57:41","guid":{"rendered":"http:\/\/orilliahomeinspector.com\/blog\/home-inspection\/green-building-consumer-information\/"},"modified":"2022-08-24T16:47:53","modified_gmt":"2022-08-24T16:47:53","slug":"green-building-consumer-information","status":"publish","type":"post","link":"https:\/\/orilliahomeinspector.com\/blog\/green-building-consumer-information\/","title":{"rendered":"Green Building – Consumer Information"},"content":{"rendered":"

Green Buildings \u2013 NACHI excerpts<\/span> <\/span> <\/strong><\/p>\n

 <\/p>\n

Many new buildings have features such as passive solar design, photovoltaic systems and solar thermal systems. With the new energy awareness that has been created and the governments involvement in promoting green energy saving concepts, green will be introduced to more homes and systems. The energy consumed by homes if roughly 40% in the United States of America and will become a principal target for controlling sky-rocketing energy costs. Up to 85% of the energy used today is non-renewable and is not projected to change in the foreseeable future.<\/span><\/p>\n

Passive design<\/span> <\/a> refers to home design which uses natural methods of heating and cooling, and which requires few or no mechanical devices\u00a0and minimal or no\u00a0consumption of other fuel.\u00a0<\/span><\/p>\n

Heating<\/span> <\/strong><\/p>\n

Passive solar heating uses the sun\u2019s energy to heat a home. Typically, the home is designed and oriented to collect sunshine through large, south-facing windows. Sunlight shines into the home onto materials with high thermal mass<\/span> , such as concrete, masonry or stone, which absorb sunshine and store it as heat, slowly releasing it over time to warm the home interior.<\/span><\/p>\n

\u00a0Active<\/span> <\/a> solar heating uses the sun\u2019s energy to heat a home, but heat is distributed through the home with the help of mechanical equipment such as fans, requiring the use of some electricity.<\/span><\/p>\n

Green Improvements <\/span> <\/strong><\/p>\n

LOW-FLOW TOILETS<\/span> <\/strong><\/p>\n

Toilets consume 30% to 40% of the total water used in homes, making them the biggest water users. Replacing an older 3.5-gallon toilet with a modern, low-flow 1.6-gallon toilet can save an average of two gallons-per-flush (gpf),\u00a0or 12,000 gallons of water per year. Low-flow toilets usually have 1.6 gpf marked on the bowl behind the seat or marked inside the tank.<\/span><\/p>\n

Another method for reducing the volume of water used with each flush is to install a water-filled plastic bag (called a displacement bag<\/span> <\/em> ) in the water tank. The old version of the displacement bag was a brick.\u00a0<\/span> <\/em> <\/span><\/p>\n

Protecting the Home Foundation\u00a0<\/span> <\/span> <\/strong><\/p>\n

Moisture allowed to penetrate next to the foundation can cause several problems:<\/span><\/p>\n

Softening the soil<\/span> <\/strong> : Moist soil may be less able to support the weight of the structure above. Ontario Building Code requires larger footings in moist or un-disturbed soil.<\/span><\/p>\n

Expansive soil<\/span> <\/strong> : Certain types of soil, especially certain types of clay, expand to many times\u00a0their original size as\u00a0they absorb moisture.\u00a0Expansive soil can easily damage foundations. <\/span><\/p>\n

Foundation undermining<\/span> <\/strong> : E<\/span> <\/strong> nough moisture flowing under a foundation can carry away soil and leave the foundation unsupported in areas. <\/span><\/p>\n

Microbial growth<\/span> <\/strong> : <\/span> <\/strong> Moisture allowed to collect in crawlspaces and basements may create conditions which encourage the growth of microbes such as mould fungus and soil-borne bacteria which may represent potential health hazards.\u00a0<\/span><\/p>\n

Slope Grade Away from Foundation<\/span> <\/strong><\/p>\n

Grade around the home perimeter should slope away from the foundation for at least six feet. The slope should effectively route surface run-off away from the foundation. <\/span><\/p>\n

Hillside<\/span> <\/strong> Run-Off<\/span> <\/strong><\/p>\n

Homes built on hillsides should have a feature installed which will route surface runoff away from the foundation. Swales and drainage ditches are two commonly used methods.<\/span><\/p>\n

Planting Beds<\/span> <\/strong><\/p>\n

Planting beds located next to the home may create problems by holding moisture next to the foundation.<\/span><\/p>\n

Downspouts<\/span> <\/strong><\/p>\n

To minimize erosion and route run-off away from the foundation, downspouts should have extensions or should terminate at a perimeter drain or splashblock. Some method should be used to prevent erosion.<\/span><\/p>\n

Engineered Lumber<\/span> <\/strong><\/p>\n

Engineered wood products use recycled\/reconstituted wood chips or strands and finger-jointing (the process of gluing larger pieces of wood together) to produce a variety of building products such as structural framing lumber and trim material.<\/span><\/p>\n

Waste wood and entire trees can be used to produce products, regardless of species and age.<\/span><\/p>\n

Engineered wood is generally straighter, more stable and more structurally consistent than dimensional lumber. In joist and rafter applications, the reconstituted products are particularly useful because they can span long distances with less sagging than similarly-sized conventional lumber.<\/span><\/p>\n

Cost<\/span><\/p>\n

Engineered wood is generally more expensive than dimensional lumber, but cost is offset to some degree by labor savings and improved quality.<\/span><\/p>\n

Types of Engineered Lumber<\/span> <\/span> <\/strong><\/p>\n

\u00a0<\/span> <\/span> <\/strong><\/p>\n

Oriented Strand Board (OSB)<\/span> <\/strong><\/p>\n

OSB has replaced plywood in many applications. It is manufactured using waterproof heat-cured adhesives and rectangular-shaped, aligned wood strands.\u00a0 Strand direction changes in each layer in a manner similar to the way the veneers within a sheet of plywood alternate direction. This results in a structural engineered wood panel that shares many of the strength and performance characteristics of plywood<\/span><\/p>\n

\u00a0<\/span><\/p>\n

Finger-jointed Studs<\/span> <\/strong><\/p>\n

Finger-jointed studs are manufactured by milling tightly-fitted joints into short pieces of lumber which would otherwise be considered scrap. These short pieces are glued together using a method that creates joints that are stronger than the wood. Joints will lose strength, though, if material is not protected from weather.<\/span><\/p>\n

\u00a0<\/span><\/p>\n

I-beams<\/span> <\/strong><\/p>\n

I-beams are framing members typically used as floor joists and sometimes as rafters. They are \u201cI\u201d shaped in cross section, dimensionally stable, available in a variety of structural ratings and are produced in lengths up to 60 feet. They consist of a plywood or oriented strand board (OSB) web to which a top and bottom chord is attached, usually either 2 x 2, 2 x 3 or 2 x 4, depending on the structural rating of the I-beam.<\/span><\/p>\n

Microlams<\/span> <\/strong><\/p>\n

To produce Microlam\u00ae Laminated Veneer Lumber (LVL), sheets of veneer peeled from logs are carefully dried, ultrasonically graded for strength, and evaluated to ensure uniform thickness and moisture content. The sheets are coated with adhesive, layered, and subjected to heat and pressure to achieve a permanent bond. As with I-beams, Microlams are available in long lengths.<\/span><\/p>\n

Glu-Lams<\/span> <\/strong><\/p>\n

Glu-Lams are beams manufactured by gluing together layers of dimensional lumber. Engineered beams are typically more stable and stronger than similar sized dimensional beams and can be manufactured with a camber<\/span> . Glu-Lam beams\u00a0can also be manufactured in large sizes which would be much more expensive if\u00a0milled from\u00a0a solid piece of wood. Glu-Lams are often left exposed. Building beams by laminating smaller pieces of dimensional lumber allows for more efficient use of wood and helps save trees.<\/span><\/p>\n

Parallams<\/span> <\/strong><\/p>\n

Parallams are engineered wood beams manufactured by gluing together aligned wood strands and bonding them using a microwave process.<\/span><\/p>\n

\u00a0<\/span><\/p>\n

Wall Framing<\/span> <\/span> <\/strong><\/p>\n

Wood and steel wall framing members act as thermal bridge<\/span> <\/a> s\u00a0in transmitting heat through the building envelope. Value engineering uses two methods for reducing heat transfer\u00a0from thermal bridging.<\/span><\/p>\n

A thermal break<\/span> <\/strong> is a layer of insulation which interrupts the conduction of heat through building envelope framing members. <\/span><\/p>\n

Reducing the number of framing members<\/span> <\/strong> in the building envelope. By installing studs on 24-inch centers instead of 16-inch centers, fewer studs are used, which means a greater percentage of the overall exterior wall, floor or roof\u00a0cavities will be filled with insulation.\u00a0<\/span><\/p>\n

Structural Insulated Panels<\/span> <\/strong> (SIP’s)<\/span><\/p>\n

Structural insulated panels<\/span> are high performance building panels used in floors, walls, and roofs in residential and light commercial buildings. They are an alternative to conventional framing methods.<\/span><\/p>\n

The panels are made by sandwiching a core of rigid foam plastic insulation between two structural skins of oriented strand board (OSB). Other skin material can be used for specific purposes. SIPs are manufactured under factory-controlled conditions and can be custom designed for each home. The result is a building system that is extremely strong and energy efficient\u00a0because\u00a0there are no\u00a0wall studs\u00a0to transmit home heat to the outside. Panels are available in a variety of sizes, thicknesses and core\/skin materials. <\/span><\/p>\n

Insulating Concrete Forms<\/span> <\/strong> \u00a0 (ICFs)<\/span><\/p>\n

Insulating concrete forms<\/span> are forms for poured concrete walls which are designed to remain in place as a permanent part of the wall assembly.<\/span><\/p>\n

The forms, made of a foam similar to Styrofoam, are made up of pre-formed, hollow, interlocking blocks. As blocks are assembled, rebar is installed, and then concrete is poured to fill the cavities, so that once the concrete is dry it forms a post and beam grid inside the blocks. <\/span><\/p>\n

In addition to providing a continuous insulation and sound barrier, the foam forms have plastic strips embedded which provide a means for attaching interior and exterior wall coverings.<\/span><\/p>\n

Insulation<\/span> <\/strong><\/p>\n

Insulation is rated by its thermal resistance, called R-value, which indicates\u00a0its resistance to heat flow. Higher R-values indicate\u00a0greater effectiveness at reducing heat flow. The R-value of thermal insulation depends on the type of insulating material, its thickness and its density. Installing more insulation in a home increases its R-value and helps keep heat from moving through the building envelope.<\/span><\/p>\n

The total wall assembly R-value will depend upon what materials are installed in the wall, floor or roof\u00a0assembly<\/span> <\/em> , not just the R-value of the insulation. In calculating the R-value of a multiple-layered wall, floor\u00a0or roof assembly<\/span> , the R-values of the individual layers are added together.\u00a0 The R-value of a wall assembly is also affected by the quality of the installation and the\u00a0properties of the insulation material. <\/span><\/p>\n

To a certain extent, more tightly-packed wall cavities will allow less air-flow through the wall assembly, which\u00a0reduces the amount of heat flow since air carries heat. <\/span><\/p>\n

Insulation packed too tightly will lose some of its effectiveness because most insulation works by trapping air in microscopic air pockets. When these tiny pockets are crushed, R-value is reduced.<\/span><\/p>\n

Insulation is also affected by thermal bridging<\/span> <\/a> . Thermal bridging commonly occurs where framing members in the building envelope interrupt the insulation. Wood studs have an R-value of approximately R-1 per inch. Fibreglass insulation is approximately R-3.3 per inch. This means that studs will conduct heat through the wall more quickly than the insulation, forming a thermal “bridge” between the conditioned air interior and the exterior.<\/span><\/p>\n

Because heat rises, ceilings and attics typically have more insulation installed than walls or floors<\/span><\/p>\n

Air Movement in Buildings<\/span> <\/strong><\/p>\n

The building envelope\u00a0consists of those\u00a0parts of the floor, wall and roof assemblies designed to\u00a0control the loss of conditioned air. Conditioned air<\/span> <\/em> refers to air which has been warmed, cooled or had moisture added to or removed from it. <\/span><\/p>\n

Building science refers to the study of how moisture, heat and air move through buildings and how their movement affects human health, comfort and the cost of operating homes. Air movement is an important influence on indoor environments because\u00a0air commonly moves across building envelopes. We want to keep control of indoor air quality, and air movement across the building envelope has the potential to affect the quality of indoor air dramatically. <\/span><\/p>\n

Circular air movement occuring within a building envelope is called circulation. Air movement across the building envelope<\/span> is called infiltration<\/span> <\/em> if air is moving into the conditioned space and exfiltration<\/span> <\/em> if it is moving out.<\/span><\/p>\n

Air movement in a home\u00a0can\u00a0create\u00a0uncomfortable moisture or temperature levels, or introduce dust, pollen, mold spores, radon or other pollutants or health hazards into indoor air.<\/span><\/p>\n

INDOOR AIR MOVEMENT<\/span> <\/strong><\/p>\n

Air movement through the building envelope is\u00a0caused by the following:<\/span><\/p>\n

Depressurization <\/span> <\/strong> of buildings by mechanical ventilation devices and the combustion process.<\/span> <\/strong> <\/span><\/p>\n

Poorly-balanced HVAC systems<\/span> <\/strong> –heating and cooling equipment both use blowers to distribute conditioned air throughout buildings. Depending on how well the system is balanced, this can establish air pressure differences in various\u00a0parts of a building, which can cause air to move in or out through the building envelope.\u00a0<\/span><\/p>\n

Ventilation fans<\/span> <\/strong> for bathrooms, laundries and range hoods all\u00a0push conditioned air to the outside which must be replaced. Typically, this make-up air has come from air infiltration around doors and windows and through other gaps in the building envelope.\u00a0 <\/span><\/p>\n

Combustion processes<\/span> <\/strong> in appliances such as boilers, furnaces, heating stoves and water heaters. They pull air from the home interior as they exhaust the products of combustion to the exterior. <\/span><\/p>\n

Temperature differentials<\/span> <\/strong> between indoor and outdoor air. <\/span><\/p>\n

Thermal buoyancy<\/span> <\/strong> describes the action of air as it is warms. Because heated air is less dense it rises, moving from a cool, high-density area toward a warm, low-density area. <\/span><\/p>\n

Stack effect<\/span> <\/strong> describes the action of warm air rising through a building. As warm air rises, it pulls cold make-up air into the home through the lower building envelope and pushes warm air out through the upper building envelope. This can have a significant effect on homes, pulling undesirable hot or cold air, moisture or environmental pollutants and hazards (radon) into the home. <\/span><\/p>\n

Convection currents<\/span> <\/strong> , or the movement of cooler air being pulled in to replace rising warm air, will establish convection currents at any place in the home in which significant temperature differences exist.\u00a0 This occurs mainly in living space and attics. Supply and return registers are key points of temperature<\/span> <\/em> differences, but\u00a0also key points of pressure<\/span> <\/em> differences caused by <\/span> Make-Up Air<\/span><\/p>\n

As air is exhausted from the home by the methods mentioned above, it must be replaced by make-up air. Unless ventilation devices are deliberately installed to provide make-up air, it will be pulled into the home through the building envelope. Uncontrolled make-up air may carry with it excessive moisture or heat (or lack of heat). It may infiltrate from the exterior, the crawlspace or the attic. <\/span><\/p>\n

In extremely tightly built homes, make-up air has been supplied from sewers after water was sucked out of the plumbing traps. Installing a Heat Recovery Ventilator (HRV) or Energy Recovery Ventilator (ERV) offers more control over the supply of make-up air, allows for more efficient use of heating and cooling equipment and reduces heating and cooling costs <\/span><\/p>\n

Heat and Energy Recovery Ventilators<\/span> <\/strong><\/p>\n

Inspecting HRVs and ERVs<\/span> lies beyond the scope of a General Home Inspection, but inspectors should be able to recognize them.<\/span><\/p>\n

HRVs use a heat exchanger to transfer heat between home exhaust-air and make-up air without allowing the two airstreams to mix. This exchange pre-warms (or pre-cools) make-up air, which in turn lowers heating and cooling costs. <\/span><\/p>\n

ERVs perform the same function but in addition, they also transfer moisture. Systems are available in different sizes in order to maintain as closely as possible an ideal 3.5 air changes per hour<\/span> <\/em> .<\/span><\/p>\n

HRVs and ERVs are typically installed in line with the home heating\/cooling ducts and may include filtration devices such as High Efficiency Particulate Air<\/span> <\/em> (HEPA) filters.<\/span><\/p>\n

Air Barriers<\/span> <\/strong><\/p>\n

Air barriers<\/span> <\/a> <\/span> are assemblies or components designed to resist the flow of air through the building envelope by resisting air pressure differences. They may consist of sealed drywall, exterior wall sheathing or even tightly-packed insulation (sprayed cellulose or foam). They may be installed anywhere in the wall, floor or ceiling assembly, and toward the exterior or interior.<\/span><\/p>\n

Air barriers should be:<\/span><\/p>\n