Daylight design is an involved, continual process which connects a project from conceptual design through construction, requiring the coordination of the architect, interior designer, mechanical engineer, specification writer, and contractor.
Daylight modeling to test and verify major design decisions is recommended at each construction phase regardless of the LEED option. This is increasingly common on high- performance buildings but is not standard practice. Expect to incur “soft costs.” Due to the many project variables that might come into play, estimating these costs is beyond the scope of this study.
Ideally teams would use one daylight model throughout a project to inform an integrated process. However, different models may be created by different team members for their work in different stages of design.
Concept Design

Assess exterior massing options

Shading analysis—assess options and see contextual impact

Assess opportunities to exploit major views

Schematic Design

Establish appropriate window-to-wall ratios satisfactory for daylighting, views, and/or natural ventilation potential while coordinating with code requirements and energy targets

Interior layout options based on testing illumination levels at the main task surfaces

Design Development

Glare reduction strategies to refine building fenestration

Consider and test properties of interior finishes

Test different glazing properties for glare reduction

Additional cost will be added to each project pursuing this point because of the requirement that “acceptable” glare control devices be “not-fixed” (operable) and must be installed on all transparent glazing in regularly occupied spaces, whether or not within the compliant regularly occupied space and whether or not the space receives direct sunlight. “Acceptable” interior and/or exterior glare control devices include operable blinds, shades, curtains, louvers, screens, and awnings. “Unacceptable” glare control devices include
fixed or permanent overhangs, fins, louvers, frits, and tints. These new requirements place occupants in the driver’s seat of their personal and seasonal visual comfort.
Simulation options incorporate two new concepts: “spatial daylight autonomy” (sDA)
and “annual daylight exposure” (ASE). sDa describes sufficiency of ambient daylight levels within interior environments, and ASE describes the potential for visual discomfort within interior environments; balancing these two concepts determines the level of LEED compliance. The below narrative describes each of the different options’ process and associated “soft costs.”
Additional notes on soft costs according to each option follow.
Option 1: Simulation – Spatial Daylight Autonomy
This option likely requires specialist consultation and the use of specific software which can generate sDA ratios and single-point-in-time calculations. This is the most lengthy of the three options, as each space must be looked at individually. It is likely most appropriate for projects which incorporate a variety of spaces, for projects with many different orientations, or for smaller projects where there is a desire for a high level of specificity.
Option 2: Simulation – Illuminance Calculations
This option is most similar to requirements in previous versions of LEED, so firms may have the capability to perform the work without specialist consultation. An added benefit is that Illuminance calculations are the most common output for daylighting simulation software. Do, however, budget time for researching historic meteorological data to fine- tune the simulation to the site microclimate.
Option 3: Measurement
Projects can comply with this option with or without incorportating simulation. That typically makes it a lower-cost option on design costs, but with less certain outcomes.
Allocate time for a minimum of two site visits, per LEED requirements. Two people onsite with a set of plans showing the gridded areas where measurements will be taken and a light meter can accomplish this together during the specified times. One would use the light meter to measure daylight levels point-to-point while the other would record the data, time, and outdoor conditions (description and daylight level). Teams should attempt to plan their site visits on days with ideal conditions.
All options: Glare control devices
LEED v4 has tighter controls for glare control devices than previous versions of LEED.
All glare-control devices must be operable by the building’s occupants to address unpredicted glare. Automatic devices with user override are acceptable. Acceptable devices may include interior window blinds, interior shades, curtains, movable exterior louvers, movable screens, and movable awnings. Although these strategies may be useful for other reasons (such as bird protection and architectural shading), fixed elements are not considered glare control devices as noted earlier in this chapter. They are therefore excluded from this study. 
Note on architectural solutions and glazing
Many architectural choices contribute to successful daylighting, including building orientation, geometry (shallow versus deep floorplates), and interior courtyards and atria. These choices would be considered in the context of overall building goals and an integrative design process and are not quantifiable in the scope of this study.
The level of glazing is usually not driven by LEED or sustainability. In fact, daylighting experts, engineers, and architects have all pointed out that too much glazing contributes to glare and overheating, without adding useful daylight or views. Therefore glazed area is considered a project-specific factor here. If anything, LEED projects may be more likely to realize cost savings compared to standard projects. Factors in those savings may include the direct cost of glazing versus opaque wall area, reduced sizing in mechanical systems, and reduced energy modeling costs (to prove energy code compliance in situations where buildings are overglazed).
We have provided a cost estimate for skylights, because it is less common to incorporate them except on a project focused on daylighting, often due to LEED.
*Daylight sensors are not a credit requirement, but would be commonly used in order to realized lighting energy savings from daylighting strategies.
Cost Synergies
SSc1: Site Assessment
EAp2/c2: Energy Performance
EQc6: Interior Lighting
EQc8: Quality Views