Basics of Daylighting in a Green Environment
The use of natural sunlight, known as daylighting, to illuminate a building can save energy, reduce operating costs, create visual appeal, and enhance occupant health and productivity. The U.S. Green Building Council Leadership in Energy and Environmental Design (LEED™) rating system encourages the use of daylighting to achieve high performance buildings. This course provides an introduction to the use of daylighting in commercial spaces. The course objective is to show why daylighting should be considered, the basic guidelines of using daylighting and some words of caution when using certain daylighting techniques.

2.6 Daylighting Related Design Issues - Interior

The following guidelines, adapted from "Tips for Daylighting" from Lawrence Berkeley National Laboratories, can help make a daylighting design more effective:

Space Planning

  • Locate activities according to light requirements. Put rooms with little need for daylight or with infrequent use, such as service or washrooms or high use of audio-visual or video display (VDT) equipment in non-perimeter areas. Locate tasks with higher lighting needs nearer the windows. Group tasks by similar lighting requirements for efficient use of electric lighting, and by similar schedules and comfort needs.
  • Locate activities according to comfort requirements. Place flexible tasks or low occupancy spaces where there may be unavoidable glare, not enough daylight, or direct sun penetration. These spaces may at times be thermally or visually uncomfortable. If tasks are fixed and inflexible, comfortable glare-free conditions are required.
  • Maintain daylight access. Furniture layout should not block light for spaces farther from the window. Do not position full-height partitions, bookshelves, or files parallel to a window wall if possible.
  • Use light-transmitting materials for partitions where possible. Use clear or translucent materials in the upper portion of full-height partitions. If this approach is taken in corridor walls, corridors may be adequately lighted just by this spill light.
  • Shield occupants from views of highly reflective surfaces outside, such as mirrored-glass buildings, water, snow, and large white surfaces.
  • Shield sensitive occupants from bright windows. In highly glare-sensitive areas (e.g., with wide use of VDTs), shield occupants from view of sky and provide glare-controlling window coverings.
  • Keep reflected view of bright windows out of computer screens. Be very careful where VDTs are placed. Either keep them away from windows or block the screen and occupant's view of the window. Use partitions or position the screen with the window to the side and slightly turned away from the window.
  • Use west zones for service spaces. Minimize use of exposed west zones as occupied work areas. Large areas of west glazing make for difficult daylighting, high cooling loads, and uncomfortable occupants.

Overhead skylights Source: Benya Lighting Design

Interior Design

  • Don't use large areas of dark color. Generally avoid all dark colors except as accents, and keep them away from windows. Dark surfaces impede daylight penetration and cause glare when seen beside bright surfaces. For good distribution throughout the room, it is especially important that the wall facing the window be light-colored. Mullions or other solid objects next to windows should be light-colored to avoid silhouette contrasts. Keep sills and other reveal surfaces light to improve daylight distribution and soften contrast. Dark artwork can reduce daylight effectiveness.
  • Aim for recommended surface reflectances. The Illuminating Engineering Society recommends the following reflectances: ceilings >80%; walls 50-70% (higher if wall contains window); floors 20-40%; furniture 25-45%.
  • Choose matte over specular surface finishes. Matte finishes are recommended for good distribution of daylight and no reflected glare (hot spots).
  • Use light-transmitting materials. Translucent or transparent partitions are best when possible-daylight can pass through to other spaces.
  • Supply window coverings that allow individual control to accommodate different glare tolerances. Interior window shading should be light-colored for best cooling load reduction.
  • Choose colors under the right light. Choose interior colors and finishes under daylight and under the proposed electric lamps to avoid surprises in color rendering.

Property of

previous next