This page is about the development of the lighting plan for the Duplicable City Center. It is purposed to share the important developments and considerations made in relationship to the interaction of light, energy conservation, and aesthetics in this structure. This page includes the following sections:
NOTE: THIS PAGE IS NOT CONSIDERED BY US TO BE A COMPLETE AND USABLE TUTORIAL UNTIL
WE FINISH CONSTRUCTION OF THE DUPLICABLE CITY CENTER AND ADD ALL THE VIDEOS AND
EXPERIENCE FROM THAT BUILD TO THIS PAGE – IN THE MEANTIME,
WE WELCOME YOUR INPUT AND FEEDBACK
Designing an eco-lighting plan means creating a maximally energy efficient and functional plan to meet all of a structure’s lighting needs. It saves energy and reduces up-front energy infrastructure costs in off-grid village construction. As a component of achieving LEED Platinum certification, lighting is also a big part of 25 possible points of 80 needed (out of a total of 110) for LEED Platinum qualification.
One Community’s goal in open sourcing the Duplicable City Center eco-lighting plan is to help people interested in more sustainable lighting approaches, saving money through reduced energy usage, and/or curious about the process of maximizing lighting-related points for LEED Platinum certification. These goals are also part of our Highest Good Energy plan for do-it-yourself and replicable teacher/demonstration communities, villages, and cities.
Eco-lighting can be designed using several different approaches. We’ve used the Leadership in Energy and Environmental Design (LEEDv4) guidelines as our foundation. We discuss here the specifics of LEED, how you can apply these eco-lighting standards to your own projects, and our LEED Platinum design process for the Duplicable City Center. We do this with the following sections:
LEED is a third-party certification program and the nationally accepted benchmark for design, construction, and operation of high-performing sustainable buildings. LEED gives the owners the performance metrics needed for improving the holistic aspects of energy efficiency in their buildings. LEED also promotes a whole-building approach to sustainability. It does this through six key areas: sustainable site development, water savings, energy efficiency, materials selection, indoor environmental quality, and locating buildings close to transit and amenities.
The lighting aspects of LEED are emphasized in the energy efficiency and the indoor environmental quality sections. LEED Version 4 (the most current as of this writing) promotes more energy efficient lighting and lighting design with the following credited areas:
Here we discuss each of the areas where LEED points can be awarded in association with lighting. As previously mentioned, 25 points are possible with sustainable energy management and 80 points are needed (out of a total of 110) if LEED Platinum status it to be achieved. Lighting is a significant part of these 25 points. We discuss here the details of the various areas where points are awarded in a way we hope will help anyone interested in improving the sustainability of a structure. Regardless of whether or not you are interested in actual LEED certification, applying the strategies below will make your building more energy efficient and sustainable.
Note: Visit the Maximizing LEED Points Point-by-point section for layman’s-terms descriptions for how we addressed each of these areas.
Under the Energy and Atmosphere section, as a minimum prerequisite (not for points), LEED requires a 5% improvement for new construction in the proposed design over the baseline design as per ASHRAE 90.1-2010 Standard. So while the ASHRAE 2010 standard provides the minimum requirements for energy-efficient design of buildings, the proposed design has to be done using the whole-building energy simulation method (using industry software such as IES, eQuest, EnergyPro, etc.) and show a 5% overall reduction beyond the baseline. At 6% reduction, one point is awarded – all the way up to 50+% reduction where 18 points are awarded. The prescriptive lighting density allowances do not require compliance if using energy modeling to demonstrate compliance for LEED. Only the mandatory provisions should be met to demonstrate compliance.
If the building owner decides not to use the whole building simulation method, he can choose to instead meet the Prescriptive Compliance Path of the ASHRAE 90.1-2010 Standard Advanced Energy Design Guide. This requires meeting both the mandatory and prescriptive provisions of ASHRAE 2010 standard. To achieve this, interior lighting requirements are divided into a set of mandatory requirements (provisions that must be complied with regardless of the quantity of lighting that is installed) and two prescriptive methods for determining the allowed wattage for the building: whole-building and space-by space.
ASHRAE Standard 90.1-2010 requires the following mandatory lighting controls:
Through its prescriptive requirements, ASHRAE/IES 90.1-2010 additionally imposes limits on the amount of lighting power installed in the building. This is measured in watts per square foot (WPSF) to promote efficient technology and design. As stated above, designers have a choice of using the Building Area Method (whole building power allowance) or Space-by-Space Method (individual spaces).
When using the Space-by-Space Method of compliance with the standard’s prescriptive lighting power allowance requirements, Standard 90.1-2010 offers lighting power adjustment credits based on use of advanced lighting control strategies in certain offices, meeting spaces, education spaces, retail sales areas, and public spaces. Qualifying technologies range from manual dimming control to much more complex and specific automatic continuous daylight harvesting dimming (the practice of reducing electric light levels when daylight is present) with power adjustment factors (applied to the controlled lighting load of 5-30%).
Building Area Method is mainly used for projects where the entire building is for one primary use and/or for single-occupancy types of buildings. Space-by-space is more flexible and is used if the building has multiple occupancies/spaces. Space-by-space method is often used in these situations because it allows trade-offs between spaces because it compares the total specified lighting wattage for the entire building to the sum of space-by-space allowances.
This article: “ASHRAE Releases 90.1-2010–Part 1: Design, Scope, Administrative Requirements” is an excellent resource for understanding this better. It also includes an informative chart showing how the various wattage allowances have evolved over the years.
The Energy and Atmosphere for Optimizing Energy Performance credit can be as high as 18 points if total-building energy modeling is performed. The objective of this credit (of which lighting is only a small part) is to increase the level of total energy performance beyond ASHRAE 2010 standards. One point can be achieved by showing a minimum of a 6% increase in the proposed building energy performance compared to ASHRAE 2010 standards. The maximum of 18 points can be achieved if a 50% (or more) increase is shown above ASHRAE 2010 standards.
The other choice is to simply meet the prescriptive requirements of ASHRAE Advanced Energy Design Guide for your specific structure type: Small-to-Medium Office Building, Medium-to-Large Retail Building, K-12 School, or Large Hospital. Without a whole-building energy analysis though, this only awards 1-2 points.
To help people desiring maximum efficiency (and points), the Advanced Energy Design Guides provide prescriptive energy savings guidance and recommendations by building type and geographic location. These are design packages and strategies to help owners and designers achieve 50%+ site energy savings over ASHRAE Standard 90.1 2010. There are four AEDG guides:
So conducting a whole-building energy analysis and demonstrating 50% efficiency increase above ASHRAE 2010 standards shows that you are not only focused on lighting, but all areas where energy savings and energy generation through renewables are possible. The ASHRAE Advanced Energy Design Guide provides a path to meeting the 50% efficiency increase above ASHRAE 90.1-2010, Appendix G goal. The whole-building energy analysis confirms the results so appropriate points can be awarded.
The Indoor Environmental Quality Credit for Interior Lighting can award up to 2 points. One for “Lighting Control” and one for “Lighting Quality.”
For 90% or more of occupant spaces, the project must provide individual lighting controls that allow users to adjust the lighting to suit their individual tasks and preferences with at least 3 lighting levels (on, off, mid-level). Mid-level is 30% to 70% of maximum lighting levels. More levels than this though can be accomplished with dimmers, table lamps for work spaces with a mid-level setting, etc. The idea here being that the building occupant(s) should have maximum control of any space so their comfort level is improved without needing to turn on every light for the space.
This choice features eight strategies, and you must include at least four of the following eight options in your project to get the related point.
The intent of this credit is to provide occupants a connection to outdoors through daylight and views from regularly occupied spaces. This reinforces circadian rhythms and reduces the use of electrical lighting by introducing daylight into the space. This can be done by providing manual or automatic (with manual override) glare control devices (such as Venetian blinds or adjustable louvers) for all regularly occupied spaces.
To qualify for these points, simulation or measurements are accepted and there are three methods LEED accepts (click here for a resource article):
The intent of this credit is to provide quality views and giving occupants a connection to the outdoor natural environment. This can be done by providing vision glazing for 75% of floor area. “Vision glazing” is windows, or the portion of larger windows, that provide a connection to the outdoors. These are typically vertical windows between 2.5 ft and 7.5 ft above the floor. Also known as View Windows and not to be confused with Daylight Windows – windows designed to provide interior illumination and located above eye height (7.5 ft), or the portion of a window more than 7.5 ft above the floor.
To claim this point, you must include a direct line of sight to the outdoors via vision glazing for 75% of all regularly occupied floor area. Regularly occupied floor areas are “areas where one or more individuals normally spend time (more than one hour per person per day on average) seated or standing as they work, study, or perform other focused activities inside a building.”View glazing in the contributing area must provide a clear image of the exterior, not obstructed by frits, fibers, patterned glazing, or added tints that distort color balance. Additionally, 75% of all regularly occupied floor area must have at least two of the following views:
Include in the calculations any permanent interior obstructions. Movable furniture and partitions may be excluded.
Views into interior atria may be used to meet up to 30% of the required area.
Click here for the source resource for all of the above.
The intent of this credit is to increase night sky access, improve nighttime visibility, and reduce the consequences of development for wildlife and people. The credit can be achieved by satisfying the uplight and lighting trespass criteria using the backlight-uplight-glare (BUG) method (Option 1) or the calculation method (Option 2). The details of both methods and how to apply them can found at this link on the LEED USGBC website.
All LEED projects must comply with all applicable mandatory provisions of ASHRAE 90.1-2010. To meet the LEED “Optimize Energy Performance” prerequisite, it must also demonstrate an improvement in the proposed performance beyond the baseline rating as defined by ASHRAE 90.1-2010.
Prescriptive Compliance describes exactly what is required in terms of design and performance of the building according to the ASHRAE 2010 standard. The designer has to follow exact instructions and not deviate or use their own approach. A prescriptive approach might make sense in a very simple building design, such as single HVAC, water, and lighting systems. The work associated with creating an energy model is not trivial, and the associated cost is not justifiable for many projects. In those cases, the reduced documentation requirements of the prescriptive-compliance path make more sense.
The alternative to a prescriptive path is a performance-based method where the architect or designer may have greater flexibility and freedom in designing the building but aims to achieve the same performance level, as demonstrated through a building energy simulation. Trade-offs can then be taken while designing the building and using the performance path. For example, if the building has slightly lower U-value for the walls, it can offset the lower performance of the walls by using a highly efficient roof.
If the energy-modeling compliance path is chosen, selection of mandatory lighting controls can help improve the model’s overall performance. LEED looks at the reduction in energy cost, not just energy usage, and encourages projects to use advanced modeling guidelines outlined in ASHRAE 2010 Appendix G. In short, the prescriptive path is simpler and can be achieved without the aid of any software. The performance path is more complicated but can result in substantial savings.
The mandatory controls requirements of ASHRAE 2010 are relatively straightforward. They have to be met by both building simulation and the ASHRAE Advanced Energy Design Guides (AEDG) method. We discuss here all the areas related to these requirements.
ASHRAE/IES 90.1-2010 requires that all lighting systems be turned OFF when not in use. Controls may be either time-of-day, occupancy sensors, or a signal from another control or alarm system that indicates that the area is unoccupied. See our open source control and automation page for the specifics of how we’re addressing these requirements and much more.
The easiest way to satisfy this requirement is to put in occupancy sensors in areas like these:
The sensor must turn lights OFF within 30 minutes of the space becoming unoccupied. There are multiple types of occupancy sensors and they should be selected based on the space and occupancy type.
In 90.1-2010, automatic shutoff controls must be manual-ON or automatically turn the lighting ON to not more than 50% power. Exceptions include public corridors and stairwells, restrooms, primary building entrance and lobby areas, and areas where manual-ON would endanger safety or security.
The lights in each enclosed space in the building must be independently controlled by a conveniently located manual control device or automatic occupancy sensor with manual-ON or auto-ON to 50% operation. The lighting must be configured for multiple levels enabling users to select at a minimum OFF, a step between 30% and 70% (inclusive) of full lighting power, and 100% of full lighting power. Stairwell lighting must be controlled so that lighting power can be reduced by at least 50% within 30 minutes of the stairwell space becoming unoccupied. Each control device shall also control no more than 2,500 sq. ft. for a space of 10,000 sq. ft. or less and a maximum of 10,000 sq. ft. for a space greater than 10,000 sq. ft.
Main side-lighted areas directly adjacent to daylight apertures in an enclosed space 250 sq. ft. or larger require the general lighting in that area be separately controlled using either a stepped switching or continuous dimming controller. More aggressive daylight harvesting (the practice of reducing electric light levels when daylight is present) in primary and secondary side-lighted areas is rewarded with power adjustment credits. In top-lighted spaces, if the total daylight area under skylights plus the total daylight area under rooftop monitors is larger than 900 sq. ft., the general lighting must be separately controlled using either a stepped switching or continuous dimming controller.
ASHRAE/IES 90.1-2010 requires functional testing of lighting controls and systems, a service typically provided by the installing electrical contractor in a new construction project, and sometimes supervised by the designer or a commissioning agent. The standard requires the construction documents identify who will conduct and certify the testing.
The prescriptive control requirements have to be met only if path 2, ASHRAE 50% Advanced Energy Design Guides (AEDG), is chosen. ASHRAE/IES 90.1 imposes limits on the amount of lighting power installed in the building, expressed in watts per square foot, to promote efficient technology and design. Any new building design has to have lighting within the lighting power density limit. Designers have a choice of meeting the ASHRAE prescriptive requirements using the Building Area Method (whole building power allowance) or Space-by-Space Method (individual spaces, with potential additional and tradable allowances).
The Prescriptive Approach contains a look-up table to determine allowed wattage for each occupancy type. These tables are under the copyrights of the ASHRAE but can be found online by searching. Try searching for “ASHRAE 90.1-2010 Table 9.6.1” and see what you turn up. As a general guide, you’ll find wattage/ft2 ranging from a low .63 for areas like storage rooms, elevators, and stairways and highs around 1.2-1.6 watts/ft2 for areas like classrooms, workshops, “detailed manufacturing,” exhibit spaces, etc. Ranges of 1.8 to as high as 2.2 can be seen for areas like “courtrooms” and “retails sales areas” or “ring sports arena” or “emergency rooms” respectively.
The Building Area approach can be used for a single occupancy building or separate business entities within a building. The Space-by-Space approach is used for flexibility and for non-standard building types or space configurations.
This method is used for projects involving an entire building with a single, independent occupancy. The total connected lighting wattage is determined by multiplying the gross lighted area by lighting density factor according to the space type. Gross lighted area (GLA) includes basements, mezzanines and intermediate floor tiers, and penthouses, provided these spaces have a headroom height of 7.5 ft. or greater.
This method is applicable for a multiple occupancy building. The gross lighted area of the building is divided into each of the space types listed. The lighting power allowance is calculated by multiplying the area of space type by the lighting power density for that particular space.
The Building Area Method is sensitive to specific space functions and room configurations and is generally more restrictive. When a specific building type isn’t listed, “selection of a reasonably equivalent type” is permitted. The Space-by-Space Method is more flexible and is applicable to all building types. It accounts for actual room areas (e.g., lighting needs of enclosed office vs. open office) and an increase in the lighting power allowance is allowed for specific space functions.
The information on this page is meant for application by those seeking LEED Certification and also those just interested in improving their lighting efficiency and sustainability. With this in mind, and based on our research and everything discussed above, here are our recommendations for applying what we’ve learned to achieve these goals.
For new structures, here are our implementation suggestions listed from easiest to hardest based on difficulty to implement, cost, and potential to improve building-sustainability and energy efficiency:
LEED Certification guidelines can also be helpful for those interested in improving their lighting efficiency and sustainability in retrofit situations. For retrofit structures, here are our implementation suggestions listed from easiest to hardest based on difficulty to implement, cost, and potential to improve building-sustainability and energy efficiency:
The Duplicable City Center lighting plan is designed to help the building achieve a LEED Platinum rating. To do so, it meets both the prescriptive and the mandatory requirements of ASHRAE 90.1-2010 as required by LEED. As discussed above, our lighting plan looks at the maximum allowable lighting-wattage levels (as per ASHRAE 90.1-2010) as a baseline and then performs an evaluation to compare our lighting plan to this ASHRAE 90.1-2010 maximum. New structures that incorporate a 50% (or more) increase in total energy efficiency over the baseline (with lighting as a component of this) are eligible for 25 (the maximum number) of LEED points for the energy usage/management category.
Our final design will demonstrate meeting these guidelines by using the Performance-based Energy Modeling method, so our energy usage rating will be for the entire building. This means that exceeding efficiency goals in one area can then provide additional energy availability in another area. Our goal, however, is to keep our numbers as low as possible because it reduces our total up-front energy infrastructure needs and costs.
We share here our complete design process with the following sections:
Before starting the detailed design process, we wanted to generate baseline lighting levels to achieve LEEDv4 Platinum Certification (80+ pts.). To do this, we first looked only at reducing our energy consumption. We chose to focus on reducing energy consumption first because we consider this one of the easiest elements to objectively evaluate and also one of the largest contributors to our overall carbon footprint and project sustainability. We used the following zones, square footages, and power density benchmarks from the Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) as our starting point:
This would mean the following allowable watts per “zone” when using a 50% reduction (needed for maximum points) as our goal:
We then made the assumption that we will exclusively utilize LED lights (click here for details), which have higher upfront costs but consume much less electricity than traditional or compact fluorescent bulbs. Here is how LEDs energy consumption compared to traditional light bulbs to produce the same amount of light:
Assuming the use of 10W LEDs throughout the building, we could very easily calculate an estimated lighting density for each area using this formula:
Wattage allowance for each area divided by 10 = # bulbs allowed. Total area divided by # of bulbs = estimated lighting density.
This produced encouraging results with the following estimated usable lighting densities:
For ease of maintenance and inventorying bulbs, we set a goal to design the Duplicable City Center to use only 5 different bulb types for all major receptacles through the building. Because the building will have 1000s of bulbs, careful selection of the correct bulb was important and became part of the initial design and evaluation process. This chart/graphic below summarizes the results of our research into this area and why LED bulbs became the clear choice.
Light color was also an important consideration. As color temperature goes higher on the Kelvin scale, it gets whiter and then bluer, and this tends to give a colder outdoor impression. A lower color temperature is yellower and softer, and tends to feel cozy and warm. Here’s an example of the comparison:
Cooler colors are good to use in big wide-open spaces to enhance the airy feeling. Warmer colors are good to use in more intimate places like next to big chairs in the library, in the living quarters, at the dining counter, etc. LEDs come in all colors, as dimmable and non-dimmable bulbs, and also as full-spectrum bulbs with the ability to change them to any color you desire. We chose full-color bulbs for the social centers like the library, Social Dome, and Dining Dome lighting where this variety of colors would be desirable and beneficial. We further maximized the usability of these full-color lights by combining them with dimmable white lights – see the Lighting Tests section for details. We chose dimmable “warm” colored bulbs for all other areas. The selection of lighting in this case also impacts points under the Interior Lighting – Lighting Quality credit for 1 pt.
We next explored natural light and lighting placement considerations. Bringing in natural light is one of the most effective ways to make a building feel pleasant and comfortable inside while also reducing power needs for lighting. Natural light is also a hallmark of modern architecture, but the more windows you have the more heat can be lost through them and this can increase HVAC needs.
As discussed in the environmental Quality Credit – Daylighting section, there are 1-3 LEED points that can also be earned for proper designs emphasizing daylighting. Qualifying for these points can be achieved through any one of 3 methods and the details of the method we chose to use can be found in the Maximizing LEED Points Point-by-point section.
Most of the Duplicable City Center will have a good amount of natural light and natural light distribution due to the dome shape and big windows placed high up in the domes, but it is also important to complement that with properly placed interior light sources. When interior lights are chosen and placed correctly, the lighting in the room will feel more “natural,” enhance the open feeling of the building rather than distracting, simulates daylight on dark days or in the winter, and they’ll help keep the interior feeling more physically comfortable.
Using a combination of indistinct ambient light and detailed spotlighting is how this is accomplished. This is important because flat, even lighting is boring and generally less desirable, like this:
In contrast, what we want to create is more along these lines:
Notice how the second example doesn’t have a ton of natural light but it still feels open and airy. White (or very close to it) walls and ceiling accentuate this even more by reflecting light, an experience we have specifically enhanced in our structure by aiming larger lights up to reflect off these white ceiling and walls to maximize ambient light to mix with the lights from the overhead windows like this:
In areas with a more traditional ceiling (i.e. in bedrooms, bathrooms, and underneath balconies in the domes), a combination of reflective fixtures and in-ceiling can-lights or track lights will be used. A similar feeling of ambient light can be created with fixtures similar to the picture on the right and can-lights create a relatively even amount of light in a room, but still have “hot” spots underneath them that make for a far more interesting visual experience like this:
Having a general idea of how many bulbs would be allowed for each of the domes and the cupola, and having chosen LEDs for our bulb type, the next steps were dividing the building into zones based on use, choosing the specific bulbs for the different areas, and calculating how many bulbs would be needed to meet optimum and minimum lighting levels. The zones were also important for design and implementation of the control and automation details. Click this graphic for the complete zone plan:
With the desire for maximizing efficiency and credits, the criteria for number of lights per room was set to be at least a 50% reduction from the American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) lighting power density benchmarks while still meeting code-based lighting requirements for safety and comfort. We created a spreadsheet to run the necessary calculations and organize all the related information. Here’s a preview that can be clicked for the most current updates and details:
Lighting tests were the next step after all the steps in the Lighting Calculations section: identifying all the zones, choosing the specific bulbs for the various zones, comparing the lighting results for different fixtures, and calculating how many bulbs would be used in each zone. The lighting and fixture tests were done using free DIALux lighting software that allows you to see how different lighting configurations would look and also to make sure the lighting plan will supply sufficient and properly distributed light to all areas. We discuss all the lighting tests we did and what we learned from them with the following sections:
Fixture comparisons were completed for the following five lighting types to compare how different fixtures affect the way the lighting looks and distributes on the floor and walls.
Running these tests was important for aesthetics and to help us meet the ceiling, wall, floor and surface requirements of the LEED Interior Lighting guidelines section (see also the Maximization of Interior Lighting Points section). The DIALux lighting software offers thousands of fixture options, so we used the following criteria to narrow the selections down to 10-12 fixtures for each category: Fixtures must fit a standard bulb, bulbs would be 800 lumens and 4000K for the temperature, and fixtures needed to support dimmable LEDs. Below are the results for each type of fixture. Each column is labeled with a unique bulb number (eg. “DF1” means Diffused Bulb #1) to make discussion and design easier when referencing them.
Looking at all of our options side-by-side like this then allowed us to make more informed decisions when choosing the various fixtures throughout the building. What follows are the results of our selection process.
Lighting tests were especially important for the Social and Dining domes because both of these domes have two foundational lighting systems. The first is a floodlight system designed to fully light the room by reflecting light off of the ceiling. The second is a complete system of full-color spectrum lights for making these domes any color we desire. All the lights chosen are LEDs and both the floodlight system and the full-color lighting systems were designed to provide the minimum amount of light necessary for code compliance and safety. Combined, the two systems allow for maximum energy efficiency through individual lighting options wherever people want them and maximum room-color flexibility through lighting that can provide different color options throughout these primary City Center social and dining spaces.
Here are the Social Dome lighting tests with 38,000-lumen LED spotlights pointed at the ceiling and using the reflected light to light the entire dome. These tests show that just these three lights are sufficient to light the entire room if positioned and aimed properly as shown in Angle Test #3.
Here are the lighting tests using the spotlight positions identified as the best above, and then adding in all the other dimmable and full color-spectrum LED lights that will be mounted on the column and wall (fixture DS3) and used in the table lamps (fixture TL10).
Using these alone or in conjunction with the spotlights will allow us to make the lighting in the main room of the Social Dome any color we desire. This is shown below using only the colored lights (left two columns) and also with the white lights added (right two columns):
These tests confirmed that both of our choices for lighting placement and bulb selections provides the necessary lumens to sufficiently light the main Social Dome room. Independently they will meet minimum lighting needs and combined they will meet these needs and also allow us to far surpass them while being able to change the lighting color for the room (and different parts of the room) to any color we want.
Using the same criteria described above and in the Maximizing LEED Points Point-by-point section, here are the Social Dome bathroom lighting tests using DL1 for the ceiling lights and WS1 for the lights over the mirrors.
Using the same criteria described above and in the Maximizing LEED Points Point-by-point section, here are the Social Dome library lighting tests using WS9 for the wall sconces, DL6 for the ceiling lights, DL8 for the accent spot lights, and TL1 for the table lamps.
The Dining Dome lighting, like the Social Dome lighting, has two foundational lighting systems: The floodlight system and the full-color spectrum lighting system for making these domes any color we desire.
Here are the results of the same tests we did on the Social Dome. The top row of images shows just the spotlights. The middle row shows the column and wall (fixture DS3) plus the table lamps (fixture TL10) but without the spotlights and ceiling lights (Fixture DL1). The bottom row shows the combination of both spotlights and table, ceiling, and column lights. As with the Social Dome, the spotlights are dimmable and the table and column lights are dimmable full color-spectrum LED lights to provide full color-spectrum lighting options for the entire upstairs and downstairs dining areas.
Using these alone or in conjunction with the spotlights will allow us to make the lighting in the main room of the Dining Dome any color we desire, as shown here using only the colored lights (left two columns) and also with the white lights added (right two columns):
These tests confirmed that both of our choices for lighting placement and bulb selections will work to sufficiently light the main Social Dome room. Independently they will meet minimum lighting needs and combined they will meet these needs and also allow us to far surpass them while being able to change the lighting color for the room (and different parts of the room) to any color we want.
Here are these same lighting tests done for the complete and open source eco-kitchen area. What you see here is a uniform distribution of DL4 lights throughout the ceiling with hanging DF8 lights to bring more direct light to the work areas.
Here are the lighting tests showing the ideal configuration using a minimum of 70 lumens per square foot and 190 (DL4) lights to illuminate the basement and hallway.
Here are the lighting tests for the Living Dome and using the following criteria from the Maximizing LEED Points Point-by-point section: Fixtures must fit a standard bulb, bulbs would be 800 lumens and 4000K for the temperature, and fixtures needed to support dimmable LEDs.
Below are the results of our initial layout testing that also compared different combinations from the Fixture Comparisons section.
As highlighted in the above graphic, we chose DF3 for the central lights, DL1 for the ceiling lights, and TL3 for the table lamps (ref: Fixture Comparisons). We then adjusted the locations of all the lights to focus the lighting where it was desired most and updated the wall, floor, and furniture colors for accuracy. Running the tests again then produced the final bedroom lighting results shown here:
Here’s a final render of what one of these rooms will look like with the chosen fixtures:
Here are the same tests as above but showing what one of the bedrooms will look like with LIFX Full-color Bulbs used to provide different colors in the rooms. These tests show what the rooms will look like with various colored lights plus the regular lights on and also with just the colored lights on.
Using the same criteria described above and in the Maximizing LEED Points Point-by-point section, here are the Living Dome bathroom lighting tests using DL1 for the ceiling lights and DS3 for the lights over the mirrors.
Using the same criteria described above and in the Maximizing LEED Points Point-by-point section, here are the Central Pool and Spa Area lighting tests. This image includes the lighting for the main entryway using fixture DL1 as well as the covered entry to the Living Dome using fixture DL4. Fixture DL4 is used for all the other overhead lights here too.
Using the same criteria described above and in the Maximizing LEED Points Point-by-point section, here are the Sunrise Patio lighting tests using fixture DL4 along the patio-level perimeter and something like DS3 for the overhead spotlights.
Using the same criteria described above and in the Maximizing LEED Points Point-by-point section, here are the Cupola lighting tests using fixture DL4 for the fixtures along the patio-level perimeter , DL7 fixtures for the direct lights in the exterior overhang, and DL1 fixtures for the cupola interior lights.
One Community is open sourcing our complete control and automation systems for the Duplicable City Center. These include sensors for knowing when a space is being well lit by the natural lighting (such as sunlight through the windows or skylights) so lifestyle logic can adjust light levels to a predefined setting. Also automated blinds and shutters to address situations of excessive light or heat and also loss of heat through windows at night. Ambient light sensors in conjunction with motion sensors will also provide automatic modes of operation for detecting occupied versus away behaviors that save resources and create a more comfortable living environment. Visit the complete Control and Automation Systems open source hub for details.
Here we describe in layman’s terms how we applied all the LEED recommendations to the Duplicable City Center. We used this reference along with the ASHRAE 2010 guidelines: 2015 IECC Commercial Electrical Power and Lighting Systems. This section will continue to evolve until the building is complete and we’ve shared all we learned along with the results of our LEED Certification in the Final LEED Points Awarded Summary section. Our goal in all sections was full points for a total of 25 of 25.
We discuss this here with the following sections:
The Duplicable City Center is designed to go far beyond the requirements of the Prescriptive Provisions section. Using either the space-by-space or building-area methods, limiting the amount of watts per square foot for your structure is one of the easiest and most effective approaches to reducing total energy usage for lighting in new structures. We chose to use the space-by-space method and read this article, “ASHRAE Releases 90.1-2010–Part 1: Design, Scope, Administrative Requirements” to understand how this method works and has evolved over time. We then used a combination of ASHRAE Table 9.6.1 and several other lighting density charts from the International Energy Conservation Code (IECC) (link 1 | link 2) to come up with columns G, H, and I on the City Center Electrical Spreadsheet (tinyurl.com/dcc-lighting-details). Total Watts Per Zone (Column R) divided by Room Area (Column F) gave the applied/actual watts per square foot. Comparing the number here with the numbers in Column G and Column H shows how far we are below the ASHRAE 2013 and IECC 2015 standards. The goal is an average of 50% or greater reduction.
These numbers were then compared (using the same spreadsheet) with optimum and minimum lumen/lighting levels to determine the correct number of lights for each room (Column Q). This was calculated by dividing the Optimum Lumens Chosen (Column O) by 800 lumens – the rating of the most common bulb we’ll be using that is also the lowest-lumen bulb we’ve chosen. This is so we’re sure to meet optimum-lumen minimums even if one of the higher-lumen bulbs (like the LIFX 1100 lumen bulb) is used.
In summary, putting all this together insured we:
The Energy and Atmosphere Credit for Optimized Energy Performance is probably the most difficult to implement because it requires conducting a whole-building energy analysis and then making adjustments based on what you learn. The goal is a whole-building energy analysis showing the building demonstrates a 50% efficiency increase above ASHRAE 2010 standards. This analysis is not only focused on lighting, but all areas where energy savings are possible. The ASHRAE Advanced Energy Design Guide provides a path to meeting the 50% efficiency increase above ASHRAE 2010 goal. The whole-building energy analysis confirms the results so appropriate points can be awarded.
The Duplicable City Center is designed applying all the requirements of the Environmental Quality Credit for Interior Lighting. This area of focus can be divided into two areas of focus: “Lighting Control” and “Lighting Quality.” Lighting control implementation is a simple as including dimmers or switches that allow occupants to adjust the lighting to suit their individual tasks and preferences with at least 3 lighting levels. Mid-level is 30% to 70% of maximum lighting levels. More levels than this though can be accomplished with dimmers, table lamps for work spaces with a mid-level setting, etc. The idea is a person should be able to use any space without turning on all the lighting for the room.
Addressing “Lighting Quality” is necessary to achieve the 2nd of these two points. This can be addressed with a diversity of approaches that are described in detail in the Interior Lighting section and described here from the perspective of how to apply them in layman’s terms. You must include at least four of the following eight options in your project to get the related point and we worked to include all of them so we could maximize the efficiency of our building:
We accomplished this with fixtures that meet the “lighting at an angle between 45 and 90 degrees from the lowest point being lit” requirement and bulbs that “emit a luminance below 2,500 cd/m² (= to 2500 lumens/m2)”: Main Full-spectrum White Dimmable Bulb | LIFX Full-color Bulbs | Dimmable “Daylight” Bulbs
This was achieved through bulb selection – see selections in point above.
This was achieved through bulb selection – see selections in point above.
Direct-only overhead lighting is lighting that points directly down from the ceiling versus more diffuse lighting options. Here is a graphic showing a diversity of approaches to achieving diffuse versus direct lighting. As shown, creating diffuse lighting is mostly about choosing the correct fixtures, which is what we did. Below is an overview and you can visit the Fixture Comparisons section (above) for the specific tests and comparisons we ran.
Task lighting is another way to reduce direct-only overhead lighting, we applied this throughout the structure. Here’s a graphic illustrating how it works:
This point is about choosing the right colors for your ceilings, walls, and floors. LRV, also commonly known as the Light Reflectance Value or Luminous Reflectance Factor, determines how much light is reflected (versus absorbed) by a paint or material. Black would have a value of 0 and white has a value of 100:
Most paint companies actually post the LRV value of a color right on the fandeck of colors, so meeting the ceiling/wall/floor LRV values of 85/60/25 is as easy as picking a color with an LRV greater than the requirement. For our purposes, we chose light earth tones and off-white colors to achieve this.
As with the ceiling, wall, and floor colors, this point is about choosing the right colors for furniture and work surfaces. Stainless steel in the kitchens, light woods for tables, and light fabrics for furniture have been chosen to meet the 45% minimum reflections goals of this point. Here’s an example from the Open Source City Center Library Furniture Page.
Similar to the other reflectance guidelines, this point is about the ratio of lighting on the walls to surface lighting. The simplest approach to achieving the desired goals of this point would be to place lights far enough from walls so that the majority (90%+) of the light falls on the surfaces versus the walls. We used DIALux Lighting Tests to do this. The following steps from LEED V3 (a Pilot Credit that is now part of LEEDv4) are a simpler approach to achieving and demonstrating the required reflectance:
Again, this point is similar to the other reflectance guidelines. The simplest approach to achieving the desired goals of this point would be to use lighting fixtures that direct the majority (90%+) of light onto the surfaces versus the ceiling. We used DIALux Lighting Tests to do this. The following steps from LEED V3 are a simpler approach to achieving and demonstrating the required reflectance:
The Duplicable City Center window and door plan is designed to additionally meet the requirements of the Environmental Quality Credit for Daylighting. This consideration is all about window placement and how light falls in a room and requires computer modeling to demonstrate success. There are 3 methods LEED accepts (click here for a resource article about them all) and we’ve yet to choose which one we’ll use. Here are summaries of the three options and we’ll add our results here once they are complete.
As can be seen by the methods used to demonstrate compliance, the goal here is to create spaces that are naturally lit during the daytime. We’ve made this possible for the City Center through multiple 12′ wide hexagonal windows and 8′-wide sliding glass doors in the Social and Dining Domes, plus code compliant windows in each of the rental rooms. Several of the hexagonal windows are elevated and South-facing to maximize light harvesting and the dome-shaped structures also help to spread this light more effectively.
The Duplicable City Center window and door plan has also been designed with the Environmental Quality Credit for Views as a goal. This consideration is all about window placement and what you can see outside. Specifically, including direct line of sight to the outdoors (via vision glazing) from 75% of all regularly occupied floor area. “Vision glazing” is windows, or the portion of larger windows, that provide a connection to the outdoors. These are typically vertical windows between 2.5 ft and 7.5 ft above the floor. Also known as View Windows and not to be confused with Daylight Windows – windows designed to provide interior illumination and located above eye height (7.5 ft), or the portion of a window more than 7.5 ft above the floor.
To claim this point, we’ll demonstrate a direct line of sight to the outdoors via vision glazing for 75% of all regularly occupied floor areas. View glazing in the contributing area will provide a clear view of the outdoors. Additionally, 75% of all regularly occupied floor area will have at least two of the following four kinds of views:
Click here for the source resource for all of the above.
We’ll include in the calculations any permanent interior obstructions. Movable furniture and partitions will be excluded. Views into interior atria can and will be used to meet up to 30% of the required area, which is helpful for our design that offers views of the central pool and spa areas. To achieve all this, centrally located windows are in each of the rental rooms, multiple 12′ wide hexagonal windows and 8′-wide sliding glass doors are included in the Social and Dining Domes, and the there are nearly 360º of windows for the cupola.
Achieving the Lighting Pollution Reduction Credit is accomplished by satisfying the uplight and lighting trespass criteria using the backlight-uplight-glare (BUG) method (Option 1) or the calculation method (Option 2). The details of both of these methods and how to apply them can found at this link on the LEED USGBC website. We have not started modeling these details yet, but will add them here when they are complete.
When complete, this section will share our complete energy modeling process and results for the Duplicable City Center. We’ll include what software we used, open source spreadsheets with all the data we input, and how we used the energy model to make any decisions it influenced.
This section won’t be completed until we receive our final LEED certification. The goal is LEED Platinum, the highest rating, and we will share here our final points report and certification once we have received it. At that time, we’ll also include here any mistakes we had to correct, learnings we got from the process, and things we would do differently if we were to do it all over.
One Community’s approach to Highest Good energy is a combination of conservation, functionality, and monitoring, fine tuning, and data sharing. We know people will adopt the solutions we present if we can demonstrate lighting and energy approaches that save people money, still provide functional and aesthetically beautiful environments, and teach people how to replicate them. The Duplicable City Center will do all these things and more while helping us achieve LEED Platinum certification. This page will be where we continue to share all we learn, create, and evolve throughout the process.
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Aravind Batra: Electrical Engineer, LEED AP, Principal of P2S Engineering
Dipti Dhondarkar: Electrical Engineer
Erika Yumi Tamashiro: Architecture and Urban Design Student
James Del Monaco: Mechanical Engineer, LEED AP, Sustainability director of P2S Engineering
Joel Newman: Architectural Visualization Designer and owner/operator of Figment
Mike Hogan: Automation Systems Developer and Business Systems Consultant
Satish Ravindran: Senior Mechanical and Industrial Engineer and LEED AP