EDGE Expert flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

EDGE software

A free, web-based tool created by IFC that models a building's energy, water, and embodied-energy use against a local base case and generates the documentation used for EDGE certification.

Base case definition

The EDGE benchmark building for the same typology, climate, and location, representing standard local construction practice. All reported savings percentages are measured against this reference.

Proposed case

The project as modeled with the selected efficiency measures applied. It is compared with the base case to calculate the percentage savings in each of the three resource categories.

Savings percentage formula

(Base case value minus proposed case value) divided by base case value, multiplied by 100. EDGE applies this separately to energy, water, and embodied energy in materials.

EDGE energy metric

Annual energy consumption expressed in kilowatt-hours per square meter of floor area, covering the regulated building loads that the software models for the project type.

EDGE water metric

Annual water consumption expressed in cubic meters per occupant per year for residential projects, or per unit for commercial projects, derived from occupancy and fixture flow rates.

Embodied energy metric

The energy in megajoules required to produce the building materials used, expressed per square meter of floor area; it forms the third EDGE savings category alongside energy and water.

EDGE measures library

The catalogue of efficiency options built into the software, automatically filtered to those applicable to the chosen building typology and climate zone, each with default savings and cost data.

EDGE 20% threshold

The minimum certification requirement: at least 20% predicted savings versus the base case in energy, water, and embodied energy in materials, all three demonstrated simultaneously.

EDGE Advanced

A certification tier requiring at least 40% savings in operational energy, normally achieved by combining envelope and systems efficiency with on-site renewable energy generation.

EDGE Zero Carbon

The highest EDGE tier: 100% of operational energy supplied by renewable sources or verified carbon offsets, on top of the standard 20% savings in energy, water, and materials.

Preliminary certificate

Design-stage EDGE certification issued after a desk review of drawings and specifications. It has a limited validity period and must be superseded by a final certificate after construction.

Final EDGE certificate

Certification issued after construction, when as-built documentation and a site inspection confirm the modeled efficiency measures were actually installed and are functioning as designed.

Certification provider

An independent organization accredited by IFC, such as GBCI, SGS, BRE, or TÜV, that conducts the EDGE audits and issues the preliminary and final certificates.

EDGE Expert role

A credentialed professional who models the project in the EDGE software and advises the design team on measures. The Expert does not perform the certification audit of their own project.

EDGE certification fee

A charge paid to the certification provider, scaled to the project's gross floor area and separate from any registration fee. Use of the EDGE software itself is free.

Cool roof

A roof finished with high solar reflectance and high thermal emittance, keeping surface temperature low and reducing heat gain into the building, most effective in hot climates.

SHGC

Solar heat gain coefficient: the fraction of incident solar radiation admitted through glazing. Lower values reduce cooling loads in hot climates but may reduce useful winter heat gain.

U-value

A measure of heat transfer through a building element such as glazing, wall, or roof. Lower values mean better insulation, and the benefit is greatest in cold and temperate climates.

Night flush ventilation

Drawing cool night air through the building to remove heat stored in thermal mass. Effective in hot-dry climates with large day-to-night temperature swings.

Low-flow fixtures

Taps, showers, and toilets with reduced flow rates or dual-flush mechanisms. They are typically the lowest-cost, highest-return water efficiency measure in the EDGE measures library.

Rainwater harvesting

Collecting and storing roof runoff for non-potable uses such as irrigation, toilet flushing, or cooling-tower make-up, reducing demand on municipal supply.

Greywater recycling

Collecting wastewater from sinks, showers, and laundry, treating it, and reusing it for flushing or irrigation. It requires separate drainage and a treatment or filtration system.

Embodied energy reduction

Lowering the energy embodied in construction materials by specifying alternatives such as AAC blocks, fly-ash concrete, recycled steel, reduced finishes, and locally sourced products.

Building orientation

Aligning the building's long axis east-west to shrink the east and west façades, which receive low-angle sun that is difficult to shade. The first passive design decision.

Window-to-wall ratio

Glazed area divided by gross wall area. Raising it increases daylight but also cooling and heating loads, so the design goal is an optimum rather than a maximum.

Horizontal overhang shading

A fixed projection above glazing on the equator-facing façade that blocks high-angle summer sun while admitting low-angle winter sun, reducing cooling load without losing winter gains.

Cross ventilation depth

A rule of thumb for naturally ventilated spaces: single-sided openings ventilate to roughly 6 m depth, while openings on opposite sides reach about 12 to 15 m.

Simple payback period

Incremental green capital cost divided by annual utility savings, expressed in years. It is a fast screening metric but ignores discount rates and energy price escalation.

Life-cycle cost

Initial construction cost plus the present value of operating, maintenance, and replacement costs over the study period, minus residual value. Used to compare design options over time.

Incremental cost

The additional capital expense of a green measure over the conventional alternative. It is the numerator of the payback calculation and the basis for cost-per-percent-of-savings comparisons.

Net present value

The discounted sum of future utility savings minus the incremental investment. A positive NPV indicates the measure is financially worthwhile at the assumed discount rate.