site potential

Using Daylighting to Save Energy and Enhance Views

JulieBy Julie Lundin, NCIDQ, LEED AP ID+C, ASID, Director, Emerald Skyline Corporation

My post on the design and progress of our commercial building focused on an overview of what sustainable design is and how it impacts a building’s design and construction and on-going building operations. You can see that post here. A sustainable building utilizes many concepts, solutions and products to incorporate the six fundamental principles of sustainable design:

  • Optimize Site Potential
  • Optimize Energy Use
  • Protect and Conserve Water
  • Optimize Building Space and Material Use
  • Enhance Indoor Environmental Quality (IEQ)
  • Optimize Operational and Maintenance Practices

This post explores the concept of Daylighting and Views, which impacts two areas of the fundamental principles of sustainable design: Optimization of Energy Use and Enhance Indoor Environmental Quality (IEQ).

Daylighting is the ability to maximize or control the use of natural daylight in a building in order to reduce the need for artificial lighting and reduce energy use. Access to daylight inside a building helps create a healthy, comfortable and productive environment for its occupants while reducing as much as one-third of total building energy costs.

Implementing daylighting on a project goes beyond simply listing components to be gathered and installed. Daylighting requires an integrated design approach to be successful. It can involve decisions about the building layout, site, climate, building components such as windows and skylights, lighting controls and lighting design criteria.

The science of daylighting design is not just how to provide enough direct daylight to an occupied space, but how to do so without any undesirable side effects. Beyond adding windows or skylights to a space, it involves carefully balancing heat gain and loss, glare control, and variations in daylight availability.

To implement daylighting into a project it requires systems, technologies and architecture. Below are some of the typical components that are utilized:

  • Daylight-optimized building footprint
  • Climate-responsive window-to-wall area ratio
  • High-performance glazing
  • Daylighting-optimized fenestration design
  • Skylights
  • Tubular daylight devices
  • Solar shading devices
  • Daylight redirection devices
  • Daylight-responsive electric lighting controls
  • Daylight-optimized interior design (furniture, space planning, room surface finishes)

Since daylighting components are normally integrated with the original building design, it may not be possible to consider them for a retrofit project. We are fortunate that the retrofit of our building in Boca Raton lends itself to use daylighting to positively impact two of the fundamental principles of sustainable design. Below are some of the components that our project will utilize:

  • Optimized Building Footprint – Although usually limited to new construction, our building and site enables us to make design decisions that will allow us to create a daylight-optimized footprint. The redesign of our building will maximize south and north exposures, and minimize east and west exposures. Our new façade will face due south which is the optimal orientation for best solar access and ease of control.
  • Climate-Responsive Window-to-Wall Area – With the building sited facing south, we are specifying high-performance glazing (windows). The area is being designed to be a careful balance between admission of daylight and summertime heat gain since our project is located in South Florida.
  • High-Performance Glazing – High performance windows will generally admit more light and less heat than a typical window, allowing for daylighting without negatively impacting the building cooling load in the summer. For our project, being located in South Florida, high performance glazing is very important.
  • Daylighting-Optimized Fenestration Design – An optimized fenestration design will increase the system performance. Windows have two essential functions in a building. 1) Daylight delivery or admittance, and 2) provide a view to the occupants. Daylight admittance requires a window with high visible light transmittance and windows for view need to be clear. Our daylighting fenestration design will be composed of both of these with correct height requirements.
  • Skylights and Tubular Daylight Devices – Both of these devices utilize what is called toplighting, or admitting daylight from above. We are incorporating the use of tubular devices in our building design. These devices employ a highly reflective film on the interior of a tube to channel light from a lens at the roof to a lens at the ceiling plane. They tend to be much smaller than a typical skylight, yet still deliver sufficient daylight for the purpose of dimming the electric lighting. They will be used on the second floor where there will be interior spaces that do not have access to any windows due to our north side zero lot line site.
  • Daylight Redirection Devices – Redirection devices take incoming direct beam sunlight and redirect it. These devices serve two functions: glare control, where the sun is directed away from the eyes of the occupants, and daylight penetration, where sunlight is distributed deeper into a space that would not be allowed otherwise. We will be utilizing both of these methods in our project.   Lightshelves will be used on the south façade of the building, on both floors. The second floor interior will contain clerestory glass components that will distribute light into rooms that have no access to daylight.
  • Electric Lighting Controls - Lighting controls are essential to any daylighting system. No daylighting design will save any energy unless the electric lights are dimmed or turned off when there is sufficient illumination from daylight. If daylighting features such as windows and tubes are not paired with daylight-responsive dimming controls, then the daylighting-enhanced building will likely use more energy, not less, than a comparable building without any daylighting features. Lighting controls consist of continuous dimming or stepped-ballasts in the light fixtures, and photocells to sense the available light or turn off the electric lighting in response. We will incorporate a lighting control system in our building to take full advantage of our daylighting design and the energy savings it will provide.
  • Interior Design – An often-overlooked element in a successful daylighting design is the interior design. The interior design should consider furniture design, placement, and room surface finishes and how they relate to daylight performance. Interior walls may interfere with daylight transmission into a space. The south facing façade of our project, on the first floor will have an open concept so that daylight can penetrate and distribute more fully into the interior space. Walls and ceilings will be as reflective as possible.

To design and implement a daylighting strategy into a project requires a collaborative design process and the daylighting strategies must balance with other project design goals. Access to daylight inside buildings provides a healthier and comfortable environment for its occupants and is also linked to greater productivity. When designed with proper glare control and minimized solar heat gain, daylighting provides high-quality light while reducing energy use for lighting and for cooling.

 

 

http://www.wbdg.org/resources/daylighting.php  

Sustainable Building Design

Julie
By Julie Lundin, LEED AP ID+C,
Principal, Emerald Skyline Corporation

Our project in Boca Raton is being designed to become a LEED certified building. The U.S. Green Building Council’s (USGBC) Leadership in Energy and Environmental Design (LEED) green certification system is a tool for evaluating and measuring achievements in sustainable design. LEED consists of a set of perquisites and credits with specific requirements for obtaining points in order for a building to become LEED certified.

Many people are not familiar with the concept of sustainable design and how it relates to building construction and ongoing building operations. The built environment impacts our natural environment, our society and our economy. This concept is often referred to as the 3 P’s, people, planet and pocketbook. Sustainable design attempts to balance the needs of these areas by integrating design solutions.

EPA

EPA 2004

The main objectives of sustainable design are to reduce or avoid depletion of natural resources such as energy, water, and raw materials; prevent environmental damage caused by buildings and their infrastructure; and create livable, comfortable and healthy interior environments.

Sustainable design does not just apply to new construction; retrofitting of existing buildings should be an option and can be more cost-effective than building a new facility. With our project, we opted to retrofit as well as reposition an existing building rather than allowing further decay of the property or demolishing it and building new. My future posts will focus on specific details and products that we will utilize in our sustainable design process.

While the definition of sustainable building design continues to evolve, according to the Whole Building Design Group (WBDG) Sustainable Committee there are six fundamental principles that persist. References to some of our sustainable design solutions that will be written in upcoming posts are included below in the fundamental principles.

 

Optimize Site Potential

Creating sustainable buildings starts with proper site selection, including the reuse or rehabilitation of existing buildings.

  • We chose a contaminated site and remediated the property.
  • The project is an abandoned auto body garage that will be repurposed rather than demolished.

Location, orientation, and landscaping of a building affect ecosystems, transportation methods, and energy use.

  • A south facing orientation will enable us to harness solar energy and utilize the sun for daylighting within the structure.
  • Proximity to major bus and train lines provides alternative transportation.
  • The use of native plants and rainwater collection

Optimize Energy Use

It is essential to find ways to reduce energy load, increase efficiency, and maximize the use of renewable energy resources.

  • Solar energy via solar panels
  • LED lighting
  • Daylight Harvesting
  • Energy efficient windows, appliances, and HVAC

Protect and Conserve Water

Fresh water is an increasingly scarce resource; a sustainable building should use water efficiently, and reuse or recycle water for on-site use.

  • Cistern and water collection
  • Low flow toilets, sinks, and appliances
  • Grey water use where allowed

Optimize Building Space and Material Use

Available resources are stressed to due demands for additional goods and services. A sustainable building is designed and operated to use and reuse materials, environmentally preferable materials have a reduced effect on human health and the environment.

  • Shared uses for small building space
  • Low VOC paints, sealants and adhesives
  • Use of reclaimed wood

Enhance Indoor Environmental Quality (IEQ)

The IEQ of a building has a significant impact on occupant health, comfort, and productivity. A sustainable building maximizes daylighting, has appropriate ventilation, moisture control, optimizes acoustic performance, and avoids the use of materials with high-VOC emissions.

  • Low VOC paints, sealants and adhesives
  • Flush out building before occupancy
  • Thermal Comfort Control
  • Provide quality views

Optimize Operational and Maintenance Practices

Encourage optimal operations and maintenance systems during the design and development phases, specify materials and systems that simplify and reduce maintenance requirements; require less water, energy and toxic chemicals. Include meters to track sustainability initiatives, reductions in energy and water use and waste generation.

  • Energy and water metering
  • Recycling Waste Plan
  • Building Envelope Commissioning

 

Utilizing a sustainable design philosophy encourages decisions at each phase of the design process that will reduce negative impacts on the environment and the health of the occupants, without compromising the bottom line. It is an integrated, holistic approach that encourages the balance of people, planet and pocketbook. An integrated approach of sustainable design should positively impact all phases of a building, including design, construction and operation.

Sources:

http://www.wbdg.org/design/sustainable.php

 http://www.gsa.gov/portal/content/104462