While the broad cost implications of this credit are project-specific, it encourages code- minimum-or-less parking capacity, and reduced parking capacity will reduce construction costs as well as future maintenance costs.

While preferred parking is mostly covered by LEED v4 in LTc8: Green Vehicles, this credit includes a requirement for 5% preferred parking for carpools. Minor costs associated with preferred parking include advertisement of the spaces to potential users, unique parking decals/policies for compliant parties, and associated signage. 

Cost Synergies

The cost of this credit is project-specific. 

This credit combines formerly separate LEED concepts of stormwater “quantity” and “quality” into one credit. It also uses the term “rainwater,” which connotes a natural resource, as opposed to a problem (stormwater) to be managed. LEED v4 requires low-impact development (LID) measures to manage rainwater.

Reducing water used in irrigation can conserve scarce groundwater resources, and generally reduce demand for potable water that is becoming scarcer in many parts of the world.

However, the construction costs of water-saving systems are likely to incur premiums, particularly for more sophisticated rainwater capture and graywater treatment systems.

The cost of this credit is project-specific.

Credit requirements

This credit requires projects to provide outdoor space greater than or equal to 30% of the total site area. A minimum of 25% of that outdoor space must be vegetated (turf grass does not count) or have overhead vegetated canopy. LEED v4 also specifically calls for one of several strategies for use of that space, including:

paving or turf area which promotes outdoor social activity, and/or physical activity

garden space with diverse vegetation types providing year-round interest

Ventilation

This prerequisite requires compliance with ASHRAE 62.1-2010 for mechanical, natural, and mixed-mode ventilation systems.

Most building codes and mechanical codes require ventilation, either referencing ASHRAE 62.1 or using with similar requirements, so this prerequisite will not add any significant cost premium to most projects.

A Complex Cost Picture

Energy efficiency offers the most LEED points and the most opportunity for operational cost savings. Getting there can mean design and construction cost premiums. But with an integrated process and use of smart load-reduction strategies, some LEED projects wind up with first-cost savings, and many projects with cost premiums have favorable payback periods.

Low-emitting building materials have been around for a long time, and have become standard in some areas. LEED has increased the stringency of its emissions criteria, but these moves have largely reflected industry trends. The credit requirements in LEED v4 are also quite a bit more complex than in the past, so they will require some time to figure out the first few times a team works with them. The budget method, in particular, is complicated but ultimately easier to meet than the non-budget option. 

Cost Synergies

EQc4: Indoor Air Quality Assessment

Cost Overview

Dramatic changes in technology

New lighting technology has dramatically changed exterior lighting in the last five years. Until recently, high-intensity discharge (HID) lamps dominated the marketplace due to their low cost and wide light coverage (allowing the use of fewer fixtures). Those applications, however, contribute to light pollution, which wastes energy, interferes with biological functions of many species, and veils the night sky dome.

OPTION 1. LIGHTING CONTROL 

OPTION 2. LIGHTING QUALITY

Any cost premium for this credit option will be very project specific, as it is a function of architectural and interior design, not scope. However, note that you must spend time and effort on good lighting design to provide good usability and comfort within the space.

Yesterday’s water-saving strategies are increasingly today’s codes. LEED v4 teams will need to dig deeper for water savings, potentially with added cost premiums. However, water savings, in addition to being common sense in response to water stresses in various locations, often have favorable payback periods. 

Notes on Rainwater Capture