Airtight construction has no unintended gaps in the building envelope that allow air to leak in or out of the building or cold drafts to come in through the building envelope.
Blower Door Test
These tests determine the rate that air infiltrates a building. A powerful fan is mounted into the frame of an exterior door and the fan pulls air out of the house, lowering the air pressure inside. The higher outside air pressure then flows in through all unsealed cracks and openings.
Cubic feet per minute measures airflow.
Deep Energy Retrofits
A deep energy retrofit is a whole-building analysis and construction process that uses integrated design to achieve much larger energy savings than conventional energy retrofits.
Buildings consume nearly three-quarters of the electricity produced in the United States. A Deep Energy Retrofit (DER) can reduce an existing home’s energy appetite by 50 percent or more. It is a comprehensive renovation that affects the entire building envelope, from roof to basement. Features typically include:
- Superinsulation and fastidious air sealing
- High-performance windows
- Advanced building systems and controls
- Stringent moisture control
There are many ways to approach a DER depending on the age and structure of the house. East Branch Studio works with architects and engineers to assess the most appropriate techniques for each home.
For information about DER, see these publications from the National Grid:
Dense Pack Cellulose
Cellulose insulation is made from recycled newspaper and reconstituted wood pulp. The material is treated with Borate, a naturally occurring mineral compound which greatly increases fire, moisture, mold, and vermin resistance. It stops air infiltration and offers excellent sound insulation. When cellulose is pneumatically installed at high velocity to densities greater than 3.5 pounds per square foot, it acquires a unique air sealing property. In this process, the material behaves as a liquid, flowing into obscure bypasses and solidifying them.
An international standard for energy-efficient consumer products that generally use 20–30% less energy than required by federal standards.
Energy recovery ventilation exchanges the energy contained in normally exhausted air of a building or conditioned space, using it to treat the incoming outdoor ventilation.
Also known as green construction or sustainable building refers to both a structure and the using of processes that are environmentally responsible and resource-efficient throughout a building’s life-cycle: from siting and design to construction, operation, maintenance, renovation, and demolition. In other words, green building design involves finding the balance between home building and the sustainable environment. This requires close cooperation of the design team, the architects, the engineers, and the client at all project stages. The Green Building practice expands and complements the classical building design concerns of economy, utility, durability, and comfort.
Global warming potential was developed to allow comparisons of the global warming impacts of different gases. Specifically, it is a measure of how much energy the emissions of 1 ton of a gas will absorb over a given period of time, relative to the emissions of 1 ton of carbon dioxide (CO2).
Heat Pump Hot Water Heater
Using electricity to run a compressor, a heat-pump water heater (HPWH) extracts heat from air, often in the basement, and transfers that energy to heat water in a tank. It’s like a refrigerator, only running backwards; a refrigerator moves heat from its interior to the room it’s located in. An HPWH transfers heat from the room to a storage tank, and does it with remarkable efficiency. In fact, an HPWH is able to transfer more energy (up to 2.5 times) than the electricity it consumes.
High-Performance Tilt Turn Windows
The premise of the design is to provide a window that offers draft-free ventilation, easy cleaning, and egress. Draft-free ventilation is achieved when a user tilts the window allowing hot stagnant air at the ceiling to escape and cooler fresh air to enter the room around the sash.
Heat recovery ventilation transfers heat or coolness from stale exhaust air to fresh intake air. This balanced ventilation solution removes excess moisture, odors, and contaminants while conserving energy and enhancing comfort..
Indoor air quality measures how healthy indoor air is and what pollutants are present. It is based on the amount and composition of gasses that are being released into the air from many sources – furniture, carpeting, combustion appliances, tobacco, moisture. and building materials among others. The amount of particulate matter present is also a very important contributor to air quality.
Life Cycle Assessment
A technique to assess environmental impacts associated with all the stages of a product’s life from raw material extraction through materials processing, manufacture, distribution, use, repair, and maintenance.
Mineral Wool/Rock Wool
An insulation product made from actual stone that is very heat resistant; it is a good insulator and sound retardant.
These are very efficient ductless heating and cooling systems.
A building with zero net energy consumption, meaning the total amount of energy used by the building on an annual basis is roughly equal to the amount of renewable energy created on the site.
A net zero building, is a building with zero net energy consumption, meaning the total amount of energy used by the building on an annual basis is roughly equal to the amount of renewable energy created on the site. These buildings consequently contribute less overall greenhouse gas to the atmosphere than similar non-ZNE buildings. They do at times consume non-renewable energy and produce greenhouse gases, but at other times reduce energy consumption and greenhouse gas production elsewhere by the same amount.
Most zero net energy buildings get half or more of their energy from the grid, and return the same amount at other times. Buildings that produce a surplus of energy over the year may be called “energy-plus buildings” and buildings that consume slightly more energy than they produce are called “near-zero energy buildings” or “ultra-low energy houses“.
Traditional buildings consume 40% of the total fossil fuel energy in the US and European Union and are significant contributors of greenhouse gases. The zero net energy consumption principle is viewed as a means to reduce carbon emissions and reduce dependence on fossil fuels and although zero-energy buildings remain uncommon even in developed countries, they are gaining importance and popularity.
Most zero-energy buildings use the electrical grid for energy storage but some are independent of the grid. Energy is usually harvested on-site through energy producing technologies like solar and wind, while reducing the overall use of energy with highly efficient HVAC and lighting technologies. The zero-energy goal is becoming more practical as the costs of alternative energy technologies decrease and the costs of traditional fossil fuels increase.
The development of modern zero-energy buildings became possible not only through the progress made in new energy and construction technologies and techniques, but it has also been significantly improved by academic research, which collects precise energy performance data on traditional and experimental buildings and provides performance parameters for advanced computer models to predict the efficacy of engineering designs.
Passivhaus (passive house)
A rigorous, voluntary standard for energy efficiency in a building, reducing its ecological footprint. It results in ultra-low energy buildings that require little energy for space heating or cooling.
Like a high-performance car, Passivhaus relies on precision engineering. Since these homes are custom designed to meet our clients’ needs, we work closely with teams of architects and engineers to precisely model the technical details necessary to create the sturdiest, most energy wise, and livable homes that will stand the test of time.
Wood plus moisture equals rot, the main reason for structural decay. To keep our houses solid and dry we plan for both bulk water control, such as gutter design, and moisture that forms within the walls. Even when the air feels dry, water from condensation pools inside wall cavities. Internal condensation is inevitable so we do extensive computer modeling and detailing to ensure that the walls will dry
A typical photovoltaic system employs solar panels, each comprising a number of solar cells, which generate electrical power, through the conversion of light into electricity using semiconducting materials.
The capacity of an insulating material to resist heat flow. The higher the R-value, the greater the insulating power.
Solar Heat Gain Coefficient (SHGC)
The solar heat gain coefficient measures how much solar radiation passes 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.
A technology that uses the sun’s energy, rather than fossil fuels, to generate low-cost, environmentally friendly thermal energy. This energy is used to heat water or other fluids, and can also power solar cooling systems.
An approach to building design, construction, and retrofitting that dramatically reduces heat loss (and gain) by using much higher levels of insulation and air tightness than normal.
U-values measure how effective a material is as an insulator. The lower the U-value, the better the material as a heat insulator.
Volatile organic compounds are gases emanating from a variety of chemicals, some of which may have negative health effects in both the short and long term. Concentrations of many VOCs are consistently higher indoors (up to ten times higher) than outdoors. Household products, paints, varnishes, many cleaning, disinfecting, cosmetic, degreasing and hobby products and fuels can release organic compounds while in use, and, to some degree, when they are stored.