Pre-Design

Check local building codes to determine requirements. The project must either meet ASHRAE 62.1-2007, or local codes if they are more stringent. Since ASHRAE 62.1-2007 is often more stringent than local codes, be sure to review and be familiar with its requirements.

Natural ventilation strategies can reduce costs. Natural ventilation in particular can reduce the need for mechanical equipment as well as operational costs. Displacement ventilation, in which air is delivered at or near floor level at a low velocity, can also reduce ducting and improve equipment efficiency. In choosing a system, analyze life cycle cost tradeoffs.

Many of the strategies that contribute to meeting this prerequisite also support earning other indoor environmental quality credits and should be explored as integrated solutions. See LEEDuser's guidance on the rest of the IEQ section for ideas.

This prerequisite is paired with IEQc2: Increased Ventilation. If ventilation rates are targeted above the 30% ASHRAE requirement, projects can gain both the prerequisite and a point for EQc2. Projects pursuing IEQc2 may follow the compliance path for natural ventilation found in Chapter 2 of The CIBSE Applications Manual 10 (AM10) for both the prerequisite and for the credit.

Determine likely ventilation strategies during preliminary programming: natural, mechanical, or mixed-mode ventilation. This prerequisite is attainable with any of these strategies.

Using alternative water sources for irrigation may add costs compared with conventional irrigation. For example, a rainwater cistern will be an added cost, and space must be found for it.

If your landscaping is limited to planters and small gardens, calculate vegetated area as a percentage of the total site area (including building footprint). If the planter and garden area is at least 5% of the total site, you’re eligible for both credit options. If you’re just below that amount, you're ineligible for this credit. Consider adding planters as an amenity for the building and a way to earn the credit.

Eliminating turf grass, planting native and adaptive species, and not installing an irrigation system is the simplest and cheapest way to achieve this credit. It will also have several additional environmental and financial benefits not necessarily recognized by LEED, such as reducing mowing costs, energy use, emissions, pesticide and fertilizer needs, and maintenance. Start by evaluating this option, taking into account the owner’s expectations, the climate, and site conditions.

Ineligible projects may apply the reused building area toward MRc2: Construction Waste Management, or MRc3: Materials Reuse, but not to both