Greenbuild is buzzing about the official announcement of LEED v4. The new version adjusts the balance of points in different categories to better reflect environmental priorities, and generally shifts toward a more performance-based approach for quantifying building impacts.

Because of this shift, actual analysis is more important than ever for achieving LEED goals. With the new credit breakdown, 33 of the 104 available points in LEED v4 (BD+C) are based upon analysis of operational performance of the building. That’s more than the difference between Silver and Platinum certification — meaning architects can’t afford to wait until Design Development to know the status of these points.

Early-stage analysis can let architects understand how the building is performing before the design is locked down — and more importantly, it can help them make course-corrections to meet (or exceed) performance goals.

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There are essentially five categories of credits in LEED v4 that can benefit from fast, early-stage analysis:

  • Energy Use Reductions (EA103 – 18 points): This credit awards points based upon a percentage reduction in energy use from a baseline case. Early analysis can help architects find the best design option, identify a package of strategies that can deliver deep energy reductions, and provide an early indicator of how many points they can expect to achieve. Perhaps most importantly, it allows architects and their clients to make informed decisions about how to achieve desired results.
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An example of using strategies and bundles to achieve a reduction from a baseline, using Sefaira.

  • Water Use Reductions (WE101 and WE102 – 8 points): Similar to energy, these credits are awarded based upon a percentage reduction in water use from a baseline. Again, early modeling can help architects identify the best strategies and estimate points.
  • Renewable Energy (EA123 – 3 points): This credit is based upon percentage contribution of renewable energy (on a cost basis). This requires that architects understand (1) how much energy their design will use, (2) the annual cost of that energy, and (3) how much renewable energy can be produced on site. Early analysis can quickly provide all three numbers.
  • Daylight (EQ121 – 3 points): Architects can demonstrate compliance with this credit via either computer simulation or measurement of as-built performance. LEED v4 shifts the measurement of daylight from Daylight Factor (DF) to Spatial Daylight Autonomy (sDA) and Annual Sunlight Exposure (ASE — a proxy for glare). sDA uses actual weather data to calculate daylighting, rather than a generic overcast sky model — meaning that rules of thumb provide less reliable guidance than before, and actual analysis is even more important.
  • Integrative Process (IP102 – 1 point): LEED v4 introduces an entirely new category, Integrative Process. Its one credit (IP102) explicitly awards points for performing early-stage analysis of energy- and water-related systems. It asks the design team to explore the impact of a number of design attributes (e.g., insulation values, glazing ratios, shading, etc.), system settings (e.g. heating and cooling setpoints), and operational parameters (e.g. occupancy rates) — all elements that can be quickly studied with an early-stage tool like Sefaira. (Learn more about IP102 here.)

Without early, frequent analysis, it’s difficult for architects to know where their designs will fall in this 33-point range — and therefore  there is high risk and uncertainty regarding LEED certification. With this much at stake, architects will want to know early in design whether their designs are on track to meet performance goals — and early-stage analysis is a clear, cost-effective way to achieve this.

LEED v4 isn’t the only thing pulling the AEC  industry toward early-stage analysis, but as a well-regarded certification with a history of moving the market, its impact is likely to be powerful and sustained.

 

FURTHER READING:

Why performance based design is the future of architecture

Achieving the LEED v4 Integrative Process Credit

5 Ways Architects Can Drive Sustainability