Green Building Technology Flashcards

Question 1

What is the main goal of green building technology?

Accepted Answer

Green building technology aims to reduce the environmental impact of buildings across their whole life, from site selection and construction to daily operation and eventual demolition. It seeks to use less energy, water, and raw material while improving the health, comfort, and productivity of the people who occupy the space.

Question 2

What is embodied energy in a building material?

Accepted Answer

Embodied energy is the total energy used to extract, process, transport, install, and eventually dispose of a material. It is counted separately from the energy a building uses while in service. High embodied energy shifts much of a building's footprint into its construction phase, so designers compare options over the full life cycle.

Question 3

How does passive design differ from active building systems?

Accepted Answer

Passive design uses a building's orientation, shape, materials, and openings to manage heat, light, and airflow without mechanical equipment. Active systems, such as pumps, fans, and heat pumps, use energy to move or condition air, water, or heat. Good practice reduces loads first, so smaller and cheaper active equipment can do the remaining work.

Question 4

What is the building envelope, and why does it matter for efficiency?

Accepted Answer

The building envelope is the physical separation between conditioned interior space and the outdoors, such as walls, roof, windows, and doors. Because heat moves through this boundary by conduction, radiation, convection, and air leakage, envelope quality determines how much heating and cooling a building needs. A tight, well-insulated envelope lowers that demand first.

Question 5

What does a life cycle assessment measure in a building?

Accepted Answer

A life cycle assessment is a method that totals environmental impacts, such as energy use, greenhouse gas emissions, and resource depletion, from material production through end of life. Designers use it to compare alternatives on a consistent basis. Results depend on the boundaries and data chosen, so comparisons should use the same method.

Question 6

What is daylighting, and what are its main benefits?

Accepted Answer

Daylighting is the use of natural light to illuminate interior spaces, reducing reliance on electric lighting. Well-planned daylighting can lower lighting energy use, and it is often linked to occupant comfort and wellbeing. It requires careful control of glare and heat gain, so window size, placement, shading, and glazing choices must work together.

Question 7

Why is a building's orientation important in sustainable design?

Accepted Answer

Orientation determines how much solar radiation strikes each facade through the day and across seasons. In cooler climates, glazing on the equator-facing side can capture useful winter sun, while in hot climates, limiting west-facing glass reduces afternoon heat gain. Prevailing winds also matter for natural ventilation, so orientation should respond to the local climate.

Question 8

What is the difference between thermal mass and insulation?

Accepted Answer

Insulation resists heat flow, slowing the transfer of heat through the building envelope. Thermal mass is the capacity of dense materials, such as concrete or masonry, to absorb, store, and slowly release heat. Insulation reduces heat movement, while thermal mass moderates temperature swings, so they pair well in climates with large day-night temperature differences.

Question 9

What is an R-value, and why does it matter?

Accepted Answer

An R-value measures a material's resistance to conductive heat flow, so a higher number means greater insulating performance for a given thickness. Designers use R-values to compare insulation products and check assemblies against energy requirements. R-value ignores air leakage, thermal bridging, and moisture effects, which affect real performance.

Question 10

How does thermal bridging reduce a wall's insulating value?

Accepted Answer

Thermal bridging occurs where a material with high conductivity, such as a steel stud, concrete slab edge, or window frame, creates a shortcut through insulation. Heat then bypasses the insulated layer, so the overall wall performs worse than its insulation rating suggests. Continuous exterior insulation and careful detailing at junctions help reduce the effect.

Question 11

What is air sealing, and why is it important for energy performance?

Accepted Answer

Air sealing closes gaps and cracks in the envelope so conditioned air does not leak out and outside air does not leak in. Uncontrolled air leakage wastes heating and cooling energy, can carry moisture into wall cavities, and makes indoor temperatures uneven. Sealing uses tapes, gaskets, caulks, and foams at joints and penetrations.

Question 12

What is a blower door test used for?

Accepted Answer

A blower door test is a procedure in which a fan mounted in an exterior doorway depressurizes or pressurizes a building to measure air leakage through its envelope. Technicians may use smoke or infrared cameras to locate leaks. Results guide sealing work and show whether a building meets its airtightness target.

Question 13

How do low-emissivity windows reduce heat transfer through glass?

Accepted Answer

Low-emissivity windows have a thin, nearly invisible coating that reflects long-wave infrared radiation, which carries heat. In winter, the coating keeps indoor heat from escaping through the glass. In summer, it reduces the heat that radiates in from outside, while allowing visible light through. Coatings are combined with gas fills between panes for insulation.

Question 14

What role does a heat recovery ventilator play in an airtight building?

Accepted Answer

A heat recovery ventilator transfers heat between outgoing indoor air and incoming fresh outdoor air through a core. Most of the thermal energy in the exhaust air warms or cools the supply air, so fresh air costs little heating or cooling. Airtight buildings need such ventilation, since indoor air quality can otherwise suffer.

Question 15

What is a heat pump, and how does it differ from a furnace?

Accepted Answer

A heat pump uses a refrigerant cycle to move heat from outdoor air or the ground indoors, and it can reverse for cooling. A furnace generates heat by burning fuel or using electric resistance. Because it moves heat rather than generating it, a heat pump can deliver more heat than the electricity it consumes.

Question 16

Why do building codes and energy standards specify minimum insulation levels?

Accepted Answer

Minimum insulation levels set a baseline for thermal performance, reduce energy waste, and limit the size of heating and cooling equipment needed. Standards are written for climate zones, since a requirement suited to a mild region may be inadequate in a severe one. Designers often exceed that minimum to cut operating costs.

Question 17

What is stormwater management in green site design?

Accepted Answer

Stormwater management handles rain falling on roofs, pavement, and other hard surfaces so it does not overwhelm drainage or carry pollutants into streams. Green approaches aim to slow, filter, infiltrate, or store runoff close to where it falls. Common tools include permeable paving, rain gardens, bioswales, and cisterns, many of which mimic natural drainage.

Question 18

How does rainwater harvesting work in a building?

Accepted Answer

Rainwater harvesting collects precipitation from a roof or other catchment surface, conveys it through gutters and downspouts, and stores it in tanks or cisterns. Filtration and first-flush diverters remove debris and the initial contaminated runoff. Stored water is used for irrigation, toilet flushing, or cooling tower makeup, where drinking-quality water is unnecessary.

Question 19

What is greywater, and how is it different from blackwater?

Accepted Answer

Greywater is lightly used wastewater from showers, bathroom sinks, and laundry, carrying little human waste. Blackwater comes from toilets and carries higher levels of pathogens, which makes it harder and riskier to reuse. Because greywater is less contaminated, it can be treated and reused for irrigation or flushing where local rules allow.

Question 20

What is xeriscaping, and how does it save water?

Accepted Answer

Xeriscaping is landscape design that uses drought-tolerant plants, efficient irrigation, mulch, and soil improvement to minimize the water a site needs. Plants are grouped by water requirements, so irrigation can be targeted rather than applied uniformly. Reducing lawn area, which often needs the most water, is especially effective.

Question 21

What is a cool roof, and when is it most useful?

Accepted Answer

A cool roof has a surface with high solar reflectance and emittance, so it absorbs less sunlight and stays cooler than a dark roof. Cool roofs reduce cooling demand. They are most useful in hot, sunny climates where cooling dominates, though in cold climates a reflective roof may increase winter heating needs.

Question 22

How does water-efficient plumbing fixture design reduce consumption?

Accepted Answer

Water-efficient fixtures, such as low-flow faucets, aerators, and dual-flush toilets, deliver the same service using less water per use. Aerators mix air into the flow, while dual-flush toilets offer a smaller volume for liquid waste. Savings depend on how occupants use the fixtures, so pairing hardware with leak detection and monitoring supports long-term reductions.

Question 23

Why is site selection important for a green building project?

Accepted Answer

Site selection shapes transportation energy, access to daily services, impacts on habitat and wetlands, and exposure to sun, wind, and flooding. Building on previously developed land, near transit, and away from sensitive ecosystems often reduces environmental impact before construction begins. Good siting also allows passive strategies through orientation to the local climate.

Question 24

What is the difference between potable and nonpotable water in a building?

Accepted Answer

Potable water meets drinking water standards and is used for drinking, cooking, and bathing. Nonpotable water, such as harvested rainwater or treated greywater, does not meet drinking standards and is used for irrigation, toilet flushing, or cooling systems. Separating the two supply networks, with clear labeling and backflow protection, prevents accidental cross-connection.

Question 25

What makes a material low-emitting, and why does it matter indoors?

Accepted Answer

Low-emitting materials release few volatile organic compounds and other airborne chemicals during use, which helps keep indoor air quality acceptable. Adhesives, paints, sealants, flooring, and composite wood products can all be sources. Specifying products with low emissions reduces exposure for occupants, especially where people spend long hours or where sensitive individuals live.

Question 26

Why does outdoor air ventilation matter for indoor air quality?

Accepted Answer

Outdoor air ventilation dilutes and removes pollutants generated by occupants, building materials, cooking, and cleaning, along with moisture and carbon dioxide from breathing. Without adequate fresh air, concentrations of these contaminants can build up and affect comfort, concentration, and health. Mechanical systems, operable windows, and filtration are tools for controlling this exchange.

Question 27

What is a volatile organic compound, and where might it come from?

Accepted Answer

A volatile organic compound is a carbon-based chemical that readily evaporates into the air at normal room conditions. Indoor sources include paints, solvents, cleaning products, air fresheners, furniture finishes, and some building products. Some VOCs cause irritation or other short-term symptoms, so indoor levels are commonly reduced through product selection and ventilation.

Question 28

What causes indoor moisture problems, and why do they matter?

Accepted Answer

Indoor moisture problems usually arise from water leaks, condensation on cold surfaces, poor drainage, and humid air from occupants, cooking, and showers that is not removed. Persistent dampness supports mold and dust mites, which can worsen allergies and respiratory symptoms. Designers prevent them with proper flashing, climate-matched vapor control, and exhaust fans vented outdoors.

Question 29

What is indoor thermal comfort, and which factors affect it?

Accepted Answer

Thermal comfort describes how people feel about the temperature, humidity, air movement, and radiant conditions around them. Air temperature alone does not determine it, because surface temperatures and airflow strongly influence perceived warmth. Clothing and activity level also matter, so comfort standards combine environmental measurements with those personal factors.

Question 30

Why is the choice of wood from responsibly managed forests important?

Accepted Answer

Wood from responsibly managed forests comes from harvesting that aims to maintain forest health, biodiversity, and long-term productivity. Certified sources are verified by third-party auditors against published standards. Using wood can also store carbon for the life of the product, though that benefit depends on harvest rates and end-of-life handling.

Question 31

What is adaptive reuse, and why is it considered sustainable?

Accepted Answer

Adaptive reuse converts an existing building to a new function instead of demolishing it and building new. It preserves existing embodied energy and materials and avoids demolition waste. Successful projects still must address updated codes, insulation, and mechanical systems, since older buildings often perform poorly by current standards.

Question 32

How do recycled-content materials contribute to a green building?

Accepted Answer

Recycled-content materials incorporate salvaged or byproduct material, such as reclaimed steel, fly ash in concrete, or recycled glass in tile, which reduces demand for virgin resources. Pre-consumer content comes from manufacturing waste, while post-consumer content comes from products discarded by users. Designers should verify content claims and confirm that they meet performance requirements.

Question 33

What does net-zero energy mean for a building's annual energy use?

Accepted Answer

A net-zero energy building produces, over a year, about as much energy from on-site or nearby renewable sources as it consumes. Achieving this requires reducing demand first, then supplying the remaining load with renewable generation. Balance is measured annually, so the building may still draw grid energy at times.

Question 34

How does a photovoltaic system convert sunlight into electricity?

Accepted Answer

A photovoltaic system uses semiconductor cells that generate direct current when photons knock electrons loose in the material. An inverter converts that direct current into alternating current that matches the building's electrical system or the grid. Output depends on irradiance, panel orientation, tilt, shading, and temperature, so site assessment is essential before system sizing.

Question 35

What is a solar thermal system, and how does it differ from photovoltaics?

Accepted Answer

A solar thermal system collects sunlight as heat, usually by circulating a fluid through collectors to heat water or space. Photovoltaics instead convert sunlight directly into electricity. Solar thermal systems are often efficient for domestic hot water, while photovoltaics suit a wider range of electrical loads and can feed the grid.

Question 36

What is commissioning, and why is it important for building performance?

Accepted Answer

Commissioning is a quality assurance process that verifies building systems, such as heating, cooling, ventilation, lighting, and controls, are installed and operating as designed. Testing typically occurs before occupancy and may continue after, when seasonal conditions reveal problems. Without it, installed equipment may underperform, wasting energy and reducing comfort.

Question 37

What is a building energy model, and what is it used for?

Accepted Answer

A building energy model is a computer simulation that predicts a building's energy use based on its geometry, envelope, systems, climate data, and operating schedules. Designers use it to compare options, test strategies, and estimate performance. Model results are estimates, and they improve when inputs reflect actual construction and use.

Question 38

What is post-occupancy evaluation, and why do designers use it?

Accepted Answer

Post-occupancy evaluation is the systematic study of how a building performs after people move in, often using energy data, surveys, and interviews. It compares actual outcomes with design predictions and reveals issues such as overheating, poor controls, or unused spaces. Findings help teams correct problems and improve future projects.

Question 39

How do green building rating systems award credit?

Accepted Answer

Rating systems award points or credits for meeting defined criteria, and total scores determine a certification level. They evaluate projects across categories such as energy, water, materials, site, and indoor environment. Because each system weights categories differently, scores are not directly comparable across programs.

Question 40

How do energy audits support building performance improvements?

Accepted Answer

Energy audits assess how a building uses energy, identify inefficiencies, and estimate the cost and savings of possible upgrades. A walk-through audit reviews utility bills and equipment, while a detailed audit adds measurements such as blower door tests, thermal imaging, and submetering. Results give owners a prioritized list of measures with the best payback.

Green Building Technology Flashcards

1Foundations of green building

2Energy efficiency and the envelope

3Water and site design

4Materials and indoor environment

5Renewables, certification, and performance

Learning Resources