855773644-LEED-v5-BD-C-Reference-Guide-Launch-Edition - Page 479

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doors, garage and parking level entries, emergency exits, connections between concourses, and atrium entries.

While the prerequisite only requires entryway systems at primary exterior entrances, projects may benefit from installing entryway systems at all exterior entrances of the building.

ENTRYWAY SYSTEM LENGTH AND DESIGN

There are no length requirements for the entryway systems, but it is highly recommended to use the best practice length of at least 10 feet (3 meters) long in the primary direction of travel which allows for approximately two full steps per shoe from an average person.

Design the entryway system to accommodate and withstand specific climate conditions. Areas with high precipitation, for example, may need more absorbent mats made with mold- and mildew-resistant materials. If using rollout mats, consider selecting ones that have a solid backing. A nonporous backing captures dirt and moisture and helps prevent contaminants from collecting underneath the mat.

Regular cleaning and maintenance will extend the integrity of the entryway system. Projects are encouraged to provide routine care for these systems which is typically weekly.

Residential

• Residential projects have additional provisions for dwelling units.

DWELLING-UNIT MECHANICAL VENTILATION

ASHRAE Standard 62.2-2022 establishes minimum requirements for acceptable indoor air quality in residential buildings. Requirements for dwelling-unit mechanical ventilation systems are specified for different system types that consist of supply systems, exhaust-only systems, or balanced systems. Exhaust-only ventilation systems are only permitted in certain situations. Supply and balanced mechanical ventilation systems must provide ventilation air directly from the outdoors via a dedicated outdoor air supply duct to the unit or the HVAC equipment serving the unit. All systems must be tested and balanced before occupancy.

MECHANICAL EXHAUST SYSTEMS

ASHRAE Standard 62.2-2022 requires mechanical exhaust systems for kitchens, bathrooms, and half-baths. Recirculating range hoods do not meet the requirements of the Standard.

Fans with ENERGY STAR® labels (or performance equivalent for projects outside the U.S.) are required in all bathrooms (including half-baths). These fans use about 50% less energy than

U.S. Green Building Council LEED v5 Reference Guide for Building Design and Construction, April 2025 Launch Edition 469