EDGE Expert key terms

A free online application from IFC used to enter a project's location, building type, and design measures, then calculate predicted savings in energy, water, and embodied energy against a base case.

The reference building in EDGE representing typical local construction practice and minimum code performance for the same location and building type. Every savings percentage is measured against it.

The version of the project in EDGE that includes the efficiency measures actually specified in the design; its modeled consumption is compared with the base case to compute savings.

The reduction in predicted annual energy use, water use, or embodied energy of the improved case relative to the base case, expressed as a percentage and used to test certification eligibility.

A single design or specification choice, such as extra roof insulation or low-flow showerheads, that EDGE models to reduce resource consumption; measures can be combined and compared by cost-effectiveness.

The energy consumed to extract, manufacture, transport, and assemble building materials. EDGE estimates it for major material categories and credits savings when lower-impact options replace the base-case specification.

Inputs in EDGE describing how the building is used, including occupancy density, hours of operation, and equipment loads, which strongly influence modeled energy and water demand.

A green building certification system created by IFC that requires at least 20 percent savings in energy, water, and embodied energy in materials compared with local conventional practice.

The verified credential confirming that a project met the EDGE savings thresholds, issued after the design is modeled, audited, and the built result is confirmed.

The certification stage granted at design, based on EDGE-modeled savings and submitted documentation, before the building is constructed; it is a commitment that must later be confirmed on site.

The certification issued after construction, once an auditor confirms that the built project matches the certified design and that the modeled savings remain valid.

A higher EDGE certification tier that requires at least 40 percent on-site energy savings, together with the standard 20 percent savings in water and embodied energy in materials.

Certification for projects reaching at least 40 percent on-site energy savings and covering the remaining energy demand with renewable energy or verified carbon offsets.

An accredited professional who has completed EDGE training and can advise clients on efficiency measures, run the software, and prepare a project for certification.

An independent, qualified professional approved by the certification body who reviews design and construction evidence and visits the site to verify that certified savings were delivered.

A regional classification based on temperature, humidity, and seasonal patterns that indicates which passive and active efficiency measures will perform well in a given location.

Design choices such as orientation, form, shading, and envelope performance that keep occupants comfortable using natural energy flows before mechanical systems are sized or operated.

The share of a façade's area made up of glazing. Higher ratios usually raise cooling and heating loads, so EDGE rewards moderate, well-oriented glazing.

The fraction of solar radiation striking glass that enters the building as heat. Low values cut cooling loads in hot climates, while high values can help in cold climates.

A measure of how readily heat passes through a building element such as a wall, roof, or window. Lower values indicate better insulation and reduce heating and cooling demand.

Material added to walls, roofs, or floors to slow heat flow. Its value is greatest where indoor and outdoor temperatures differ sharply or where mechanical systems run for long hours.

An overhang, fin, louver, or screen that blocks direct sun from glazing and walls, reducing solar heat gain and glare; most useful on east and west façades in hot climates.

Delivering outdoor air through operable windows, vents, or stacks driven by wind or temperature differences, which can reduce or eliminate mechanical cooling in mild climates.

A roof finished with high solar reflectance and high thermal emittance so it absorbs less sun and stays cooler, lowering heat gain into the building and easing the urban heat island.

Heavy building materials such as concrete or masonry that absorb and store heat, smoothing indoor temperature swings; most useful where day-to-night temperature differences are large.

The ratio of heating or cooling delivered to the energy consumed by the equipment. Higher efficiency ratings reduce the energy needed to meet a given load.

The installed lighting wattage divided by floor area. Lower LPD, achieved with efficient lamps and controls, cuts lighting energy and the internal heat gains that add to cooling loads.

Generation such as solar photovoltaic, solar hot water, or small wind located at the project, which displaces purchased energy and counts toward higher EDGE energy tiers.

Faucets, showers, and toilets fitted with aerators, restrictors, or efficient flush designs that deliver the same service with less water, a core EDGE water measure.

Collecting wastewater from sinks, showers, and laundry, treating it lightly, and using it for flushing or irrigation to reduce potable water demand.

Capturing roof runoff in tanks for non-potable uses such as toilet flushing, cooling make-up, or irrigation, reducing both potable demand and site runoff.

Planting native or drought-tolerant species, limiting turf, and using drip irrigation or smart controllers so outdoor water use falls well below conventional landscaping.

Materials such as fly ash, slag, or calcined clay used to replace part of the portland cement in concrete, lowering the embodied energy and carbon of the structure.

An approach that shapes orientation, massing, openings, and shading in response to local sun path, wind, and humidity so comfort is achieved with minimal mechanical energy.

A drawing of the sun's position across the sky by hour and season for a specific latitude, used to size overhangs and orient glazing and outdoor spaces.

The additional capital cost of a more efficient design compared with the base case, the figure used to judge whether the resulting savings justify the investment.

The number of years for annual utility or water savings to repay the incremental cost, calculated without discounting; useful for quick screening but ignores long-term value.

Total cost of an option over the building's life, including initial construction, energy and water use, maintenance, and replacement, often expressed as a present value.

The discounted value of future savings minus today's added cost. A positive NPV means the efficiency investment earns more than the discount rate assumed.