EDGE Software and Modeling of Resource Savings
The engine behind the numbers
The EDGE App is a free, web-based modelling tool developed by IFC. It does not score a design against an abstract ideal; it compares your project with a base case - a reference building of the same typology (residential, office, hotel, retail, hospital, education, warehouse), in the same location and climate, built to local typical practice and code. The output is three percentages: energy, water and embodied energy in materials.
What you must actually enter
A measure only earns savings when you supply the parameter behind it: a wall or roof U-value, lighting power density in W/m², chiller COP, shower flow in litres/minute, the share of cement replaced by fly ash. Ticking a measure without data produces no reduction.
Traps candidates hit
- Assuming the base case is a fixed global benchmark - change the country and the identical design reports different percentages.
- Adding up individual measure savings. The engine applies measures sequentially, so combined savings are always lower than the arithmetic sum because effects overlap.
- Confusing a per-measure improvement figure with the project-level result.
- Overlooking that measure costs entered in the software drive the incremental-cost and payback outputs used in cost-benefit conversations.
Worked rule of thumb
Roof insulation alone models at 8% energy savings; high-performance glazing alone models at 6%. Entered together the project reports roughly 11%, not 14%, because both shrink the same cooling load. Re-read the project totals after every measure added, and never present cumulative sums in a client report.