Native vegetation

A plant whose presence and survival in a specific region is not due to human intervention or cultivation.

Natural building

This type of construction involves a range of building systems and materials that place major emphasis on sustainability. The focus is on durability and the use of minimally-processed, plentiful or renewable resources. Use of recycled or salvaged materials produces healthy living environments and maintains indoor air quality. Natural building tends to rely on human labor, more than technology, examples are cob and strawbale construction.

Natural StepTM

A trademarked, science-based framework to help organizations and communities understand and become more sustainable. It is also an international organization that provides consulting and education services around this framework.

Naturescaping

A style of landscaping that is designed to have a minimal negative impact on the environment; also known as landscaping for wildlife. It features native plants, nature-like settings, minimal use of chemicals and low water-use gardening techniques.

NBI

New Buildings Institute: a NW-based non-profit working with national, regional, state and utility groups to promote improved energy performance in commercial new construction.

Negawatt

The saving of a megawatt of power by reducing consumption or increasing efficiency.

Net metering

A metering and billing arrangement that allows on-site generators to send excess electricity flows to the regional power grid. These electricity flows offset a portion of the electricity drawn from the grid. 

Net zero energy home

A home employing site-appropriate passive solar design, site-appropriate renewable energy products, and proven energy efficiency/conservation technologies and practices, resulting in an annual contribution to the electricity grid that is equal to, or greater than, the amount of power the home uses from the grid. Common sources of energy generation are PV panels and solar hot water, wind turbines, and geo-thermal heating and cooling systems.

Night flush

Passive building strategy of flushing building structures with cool, nighttime air to minimize the next day’s cooling load: works best in conjunction with massive building envelopes.

Neotraditional planning

Based on nineteenth-century American town prototypes, this type of planning minimizes automobile use and encourages a sense of community with a town center and open public areas.

New Urbanism

A city planning movement that arose in the early 1980s that focuses on revitalizing the inner city and reforming the American suburb within an integrated regional structure. New urbanist neighborhoods are designed to contain a diverse range of housing and jobs, have pedestrian scale and to be walkable, and reflect vernacular architecture (local materials and climate). New urbanists believe their strategies are the best way to reduce traffic congestion, increase the supply of affordable housing, and rein in urban sprawl. The Florida town of Seaside is a one example of this type of planning.

NFRC

National Fenestration Rating Council: the council which rates window models for a variety of factors (light transmittance, energy efficiency, etc.) enabling an apples-to-apples comparison system.

Nitrogen oxides (NOx)

Oxides of nitrogen that are a component of air pollution. Mainly produced by the burning of fossil fuels, such as open-flame gas appliances.

NOI

Net operating income: income from real estate property after operating expense has been deducted, but before deducting income taxes and financing expenses (interest and principal payments). The formula is: NOI = gross income - operating expenses.

Non-point source pollution

Pollution, typically of water, that results from many difficult-to-pinpoint and control sources, rather than one specific source, such as pollution from a factory.

Non-renewable resources

Resources or fuels that cannot be easily made or "renewed." We can use up, or exhaust, nonrenewable fuels. Oil, natural gas, and coal are nonrenewable fuels. Natural resources that are consumed faster than can be produced.