High-Performance Building Enclosure Design for a Net-Zero Ready Habitat for Sub-Zero Wildlife
After reading this article, you should be able to:
- Define high-performance buildings and discuss the key design elements needed to achieve a high-performance building enclosure.
- Discuss the importance of continuous insulation and air and vapor barriers in designing a high-performance building enclosure.
- Discuss passive design elements that limit solar heat gain.
- Identify unique and diverse users and functions, and how they affect the design and performance of a building.
1 AIA LU/HSW; 1 GBCI CE Hour | Click here to take the quiz!
The Challenge—The Polk Penguin Conservation Center
The Detroit Zoological Society is one of the most sustainable zoos in the United States, recognized by the Association of Zoos and Aquariums for environmental leadership, earning their 2015 Green Award. The Zoo continues its commitment to sustainability with the recent addition of the Polk Penguin Conservation Center (PPCC). At 33,000 square-feet, it is the largest facility of its kind in the world and home to more than 80 penguins representing four species. The ultimate challenge to the design team of Albert Kahn Associates and Jones & Jones Architects and Landscape Architects was to create a single, high-performance building housing two very different environments … one for the penguins and the other for humans.
This article provides an overview of what defines a high-performance building, key elements of a high-performance building enclosure design, and how high-performance design was applied to the PPCC.
What is a High-Performance Building?
As with nature, buildings have evolved. Now it’s important that buildings provide occupants with a place to comfortably work, play and live. Originally, buildings were designed with focus on their local climate and use of materials found nearby … designed in a holistic manner. Technology, specifically electricity, allowed us to break the cycle of designing a building that must relate to the surrounding climate. We could have an all glass house in the desert—air-conditioned all day, then heated during the night. We were free to do what we wanted with no fear of any consequences. The energy crisis of the 1970s changed this. And now, more than 97 percent of all climate scientists are sure we’re experiencing a climate change crisis. Architects and engineers are making changes too.
Similar to a medical physician, our role as a professional architect or engineer is “do no harm.” We must design responsibly to create lower-embodied-carbon buildings. Luckily, both designers and building users/owners are starting to understand current issues. We are placing higher demands on buildings—particularly to conserve energy, reduce environmental impact and ensure user comfort. This shift in thinking has brought building design full circle, again placing focus on the building as a whole, rather than its various components. A high-performance building is achieved through a design process requiring the deliberate consideration and integration of many attributes. In addition, the building owner, design team and contractors all need to address the planning, financing, design, construction, and operations and maintenance of the building in a holistic and interdisciplinary manner.
A multitude of definitions can be found for a high-performance building, but there are two key sources that provide excellent baseline definitions. The National Renewable Energy Laboratory (NREL) is the only federal laboratory that is dedicated to research, development, commercialization, and deployment of renewable energy and energy efficiency technologies. NREL says “buildings that consume 50 percent or less of the energy of a comparable code-compliant building, while not sacrificing occupant comfort” is a high-performance building (National Renewable Energy Laboratory, 2016). Code-compliant means meeting whatever building criteria are currently required by the state and local jurisdictions for the owner to receive the certificate of occupancy. Architects and engineers should never assume code-compliant buildings are energy-efficient buildings.
The U.S. Energy Independence and Security Act of 2007 was passed with a stated purpose “to move the United States toward greater energy independence and security, to increase the production of clean renewable fuels, to protect consumers, to increase the efficiency of products, buildings and vehicles, to promote research on and deploy greenhouse gas capture and storage options, and to improve the energy performance of the Federal Government, and for other purposes.” This Act provides a second baseline definition and states that a high-performance building is “a building that integrates and optimizes on a life-cycle basis all major high-performance attributes, including energy conservation, environment, safety, security, durability, accessibility, cost-benefit, productivity, sustainability, functionality and operational considerations” (U.S. Energy Independence and Security Act of 2007, 2016). In other words, it’s no longer about a single aspect of energy conservation—but it’s about how occupants use the building and how they are affected by the building in its entirety.
It’s important to understand that having an energy-efficient building does not ensure the users are comfortable. For example, an industrial building located in the south that uses solar energy panels or high-efficiency boilers, but has no air-conditioning, will be very uncomfortable for the employees. When designing high-performance buildings, your goal is to keep in mind ALL aspects of the building: costs, operation and maintenance, its function and occupant comfort. Your goal is to design holistically, but the process to reach this goal is complex.
Achieving a high-performance building is not a simple design process with basic solutions; it does not follow a simple checklist of a multitude of elements, systems and operations to design and construct. Yes, certifications like LEED may help with the process but they do not guarantee a high-performance building. To succeed, an integrated team of owner/operator, designer and contractor must agree on project goals and work together to design and detail the project correctly and construct, commission and maintain the building properly. A high-performance building is complex with many systems: the building enclosure, mechanical systems, lighting systems, plug loads and equipment operation—to name just a few. The enclosure design can have a number of systems and elements that can use passive or mechanically-active strategies to achieve higher performance and effectiveness. This article will touch on many systems, but focus on the building enclosure.
How are High-Performance Buildings Achieved?
Many think that adding insulation and installing energy-efficient equipment is all you need to create a high-performance building, but there are numerous factors and they are all interrelated. The following are important elements and systems that one needs to pay attention to while designing a high-performance building:
• Solar Control (relating to Solar Heat Gain): Project location and climate should direct the design of the enclosure. In colder climate zones you want to design for maximum heat gain, while in warmer climates you want to limit heat gain. In temperate climates you need to design to gain and retain heat in the winter while limiting heat gain in the summer. Walls built into the earth, mass walls, sunshades, solar shelves, rainscreens and overhangs are design strategies that can be actively or passively used.
• Glazing: This is key to controlling daylighting which can cause solar heat gain and glare inside interior spaces. Glazing is also a weak link in the continuous insulation of a building, because it has an R-value lower (or higher U-factor) than the rest of the enclosure. Air leaks and water penetration are additional concerns. One needs to analyze the entire glazing unit assembly for its U-factor, coatings and reflectivity. Glazing selection is integral to how the building mass and light shelfs are designed to help with solar control.
• Continuous Insulation: High-performance buildings should have continuous insulation that exceeds standard code compliance for R-value. Alone it is not effective enough to create a high-performance building, and there is a diminished rate-of-return value for the heat flow to R-value ratio. Continuous insulation should be coupled with a continuous air and vapor barrier.
• Continuous Air and Vapor Barriers: Even the smallest crack will allow moisture and humidity into the building. This will affect dew points within the wall system and can lead to operational and maintenance issues in the future. Potentially, this could lead to mold growth or material deterioration. Continuous air and vapor barriers placed in the correct location will prevent dew points from occurring in the wall assembly where it could be harmful to the system or to the inhabitants.
• Duct Sealant and Insulation: Often overlooked, these are vital when heating and cooling a building. Properly installed, they limit the temperature change of the conditioned air traveling throughout the building and help keep the building comfortable. If inadequate or installed poorly, more heating or air-conditioning will be necessary to achieve the desired temperature. Also, sealing ducts will prevent “back drafting” of gases like carbon monoxide from escaping back into spaces instead of being exhausted outdoors. If fumes from items such as equipment are not exhausted, they could affect occupants with allergies or asthma.
• Reduced Plug Loads: Plug loads can account for almost 50 percent of energy use in a building (Higgins & Harris, 2013). Specifying the right energy-efficient equipment at the proper size will reduce plug loads. The higher the plug load the more heat is generated, which will lead to more energy needed to cool a space. Plug loads from lights, computers, monitors, etc. add up quickly to heat up a space. One can look at three areas to reduce plug loads:
o Software – Use software to a lower power mode or to turn off computers and equipment when not in use over extended periods of time.
o Hardware – Replace old, inefficient equipment with new high-efficient equipment and use systems such as advanced power strips and timers that auto- matically control loads after business hours and on weekends.
o People – Engaging building occupants is critical to any effort to impact the energy use of plug loads.
• Building Controls and Enhanced Commissioning: A high-performance building will not meet expectations if you do not verify that its systems are properly sized, controlled and functioning. Would you buy a car from a manufacturer that doesn’t test to see if it runs properly or provide a maintenance/operational manual?
How Can a High-Performance Building Fail?
Think of a high-performance building like the ecosystem of an animal’s habitat. Everything has a purpose and must function in harmony with each other to maintain the life-cycle and keep it properly balanced. Even a simple change can have a profound affect. This is also true with a high-performance building; the smallest error could lead to a large impact on the overall building. The entire enclosure, including the walls and underground slab, plays an important role in the building’s effectiveness. Temperature transference, lack of humidity control, air and vapor transmittance, solar heat gain, and lack of daylighting can all have negative impacts on the occupant’s comfort, as well as making the building energy inefficient. For example, there are completed LEED-certified projects that do not function as efficiently as modeled during design. One such building was LEED Platinum, however it was not properly commissioned and was operating with an Energy Use Intensity (EUI) rating of 78 instead of 37. It’s very important to have proper and adequate metering and controls in place to accurately monitor the systems’ function and verify they are performing as modeled.
In addition to shortcomings in the controls and commissioning of the building, there are several other ways high-performance building design can fail and waste energy or make the space uncomfortable for the occupants:
• Insulation, vapor and air barriers not designed or installed correctly will require the mechanical systems to work extra hard and use more energy.
• Ductwork not sealed or insulated properly will leak and waste conditioned air.
• Operation deviations from the original specifications can lead to poor system performance. In order to function as designed, equipment must be properly commissioned and the owner’s maintenance staff must be properly trained and given access to the operating manuals. Failure to perform proper maintenance on the mechanical systems can lead to inefficiencies over time. Always plan for periodic recommissioning.
• Unaccounted/unplanned plug loads can easily be missed during design and not included in the energy models. The importance of accurate and forward-thinking planning for this aspect of the design must be made clear to the owner, for often they will provide inaccurate numbers from user groups who incorrectly estimate their equipment needs.
Polk Penguin Conservation Center—A Case Study
A very unique building, the PPCC was designed to house two wildly different and distinct environments, an Antarctic climate for penguins and a temperate climate for humans. A popular attraction, visitors get timed-tickets to enter the exhibit. Zoo officials have planned for nearly 1,000 visitors per hour at peak times. It also provides work and animal husbandry areas for the staff who care for the birds. The center incorporates many high-performance design elements.
Designed Green—Non-Enclosure Elements
In addition to the enclosure, many green and sustainable design features are incorporated into the penguin center:
LEED Gold Criteria. The building was designed to achieve LEED Gold criteria and standards, but the client decided not to apply. Although LEED certification is not required to be a high-performance building, many LEED design features such as energy use, sustainability and siting were incorporated. But LEED wasn’t the only green design criteria used.
Net-Zero Ready. A Net-Zero Building “is an energy-efficient building where, on a source energy basis, the actual annual delivered energy is less than or equal to the on-site renewable exported energy” (Office of Energy Efficiency & Renewable Energy, 2015). The PPCC was designed to be Net-Zero ready. Originally planned to use solar panels and a geothermal system, they will be added once funds are procured. Other related systems and features currently included are:
• Energy loads for the mechanical and electrical systems were limited.
• All lights are LEDs, except a few in the animal habitat areas where the wave length from white LED light is not acceptable for a healthy penguin environment. Here metal halide lamps were used to simulate Antarctic daylighting producing 14,000 kelvin temperature over the water and 10,000 kelvin temperature over the land mass. Red 660 nanometer night lights were used for night time monitoring of space.
• Energy recovery wheels capture heat/energy from the mechanical systems and reduce energy consumption. This allows the center to use a small condensing hydronic boiler to provide supplemental heat as required. It is designed to operate most efficiently in systems with low return-water temperatures—achieving efficiencies up to 99 percent (Lobell, Spring 2016).
• CO2 and occupancy sensors in staff and public spaces are used to avoid unnecessary conditioning of air and limit ventilation to reduce energy use.
• Daylighting control systems monitor sunlight entering through the solar tubes and windows to limit the amount of lights used depending on daylight conditions and time of day.
Other sustainable, non-enclosure design elements of the PPCC include:
• Low volatile organic compound finishes and adhesives to limit off-gassing and promote healthier air quality.
• Materials made regionally and materials with recycled content to reduce the overall embodied carbon footprint of the building.
• Reclaimed wood on exhibit panels simulate the ship’s hull, not only appearing more authentic, but it’s also reuse of a perfectly good material instead of sending it to a landfill.
• A unique UV filter system to treat and reuse the penguin pool water, which allows a closed loop system without the need to add water—one of only three being used in the U.S.
Designed for the Future
This project relied entirely on donations for funding, and not all green elements the Detroit Zoo wanted to include were built. But design features are in place to add these energy-saving and green features once funds are available. The PPCC was designed to incorporate geothermal and solar systems. Also, a natural water filtration system will be added. Currently, 100 percent of the penguin pool water is filtered, but the Zoo wants all the water in the building filtered. Under construction is a solid-based anaerobic digester that will take animal wastes from the entire Detroit Zoo and capture methane gas produced, which will be used in an electric generator as an energy source. The leftover solids will then be used as class “A” fertilizer, or “Zoo Poo.” This will be the first system of its kind to be used for a zoo in North America, and one of a very few in the world.
Passive Design Elements—Key to the Enclosure Design
Passive design is at the heart of the enclosure’s design, and it’s important to use as many passive elements as possible when designing a complex building. Passive design is “using the sun’s energy for heating and cooling of living spaces. In this approach, the building itself or some elements of it takes advantage of natural energy characteristics in materials and air created by exposure to the sun” (Passive Solar, 2016). Basically, passive design limits heat gain in summer and/or amplifies heat gain in the winter. It is using elements that are not mechanical in nature, but are incorporated into the structure and will last for the life of the building. For the most part, these design elements are not associated with operational costs and have limited maintenance costs. Examples of passive design are:
- Building orientation
- Daylighting and light shelves
- Shading and sunscreens
- Window placement and size
- Glazing type and thickness
- Thermal insulation and mass (such as walls or building into the earth)
- Natural ventilation including stratification
All these passive design elements can be used within the building to limit the amount of mechanical heating and cooling necessary to make the building comfortable for the user. The PPCC incorporates many of these passive design elements to create the enclosure. In keeping with the Zoo’s directive to prioritize the penguin’s health and environment, the design was driven by the necessity to keep the penguin’s habitat cool.
Fondly referred to as a 33,000-square-foot refrigerator by the design team, the uniquely shaped building and roof are white. The design form is an abstraction of the Antarctic landscape and is inspired by tabular icebergs. White is highly reflective and helps keep the penguin habitat cool. Also, the building was sited to minimize the heating effect of the summer sun. The building shape itself shades sunlight during the summer and maximizes the solar penetration during the winter. In addition:
• Extra insulation was used in the exterior walls. Underground walls have about R11. Above ground walls have R37 for the metal, R15 for the mass and about R45 for the roof.
• Exterior windows were limited to a total of 2,155 square-feet for the entire building, including the skylights on the roof. Glazing was limited to locations where it’s necessary in the vestibules, the offices on the north side, and limited glazing into the animal habitat. The majority of the glazing has some shading elements to limit the amount of solar heat gain entering the building.
• A rainscreen exterior wall composition minimizes the amount of the building’s heat gain on the western, eastern and southern faces.
Key to successfully melding these passive designs with the other energy-saving elements is using a thorough and exacting design process.
The Design Process
When designing a building that has unique functions and multiple environments, the first thing you must do is realize, comprehend and focus on the concept that all are interrelated and affect each other. The project team must understand the design goals whether they be cost, meeting a certification like LEED, schedule, occupant health or others. As the design progresses, one should analyze/model the impact of the building’s performance for all functions. It’s easier to analyze by taking one system/material/function at a time and reviewing their various options and their impact on energy use. As shown in the accompanying flow diagram, based on the results the team will adjust the design, selection of systems, materials and details accordingly. Then they reanalyze the adjusted design to see how the building will function. The team must repeat adjusting the design and reanalyzing for building functions until the design successfully meets all unique function criteria.
For the PPCC, it was important to look at the energy modeling and ask questions such as, “What would happen if we changed the envelope to another specific type? Or “What if we increased the overhangs? How would this effect the amount of heat gain or heat loss of the overall building enclosure?” This process is repeated until a satisfactory design is reached. This will take additional time compared to designing to only meet code. Be careful, because this can turn into countless hours with diminished potential energy savings. There is no hard fast rule on how much additional time this will take; it will depend on what you are analyzing and the size and complexity of the project.
The Challenge of Multiple User Environments
The most difficult challenge of the PPCC project was designing for two very different climates/environments within a single building. Not only was there the unique penguin habitat, but staff and visitors had to be kept comfortable. In Figure 1 you can see how the two user groups, penguins and people, share this facility. The human habitat wraps around the penguin habitat … one climate surrounding the other. This drove the design of the vapor barrier and insulation in order to keep one space cool and the other warm. A natural feeling habitat for the penguins was imperative. In fact, the Zoo directed the project team to, when in doubt, always design to benefit the animal’s welfare.
This included daylighting and temperature. There are skylights in the penguin habitat, but they are a special type that allows UV light to penetrate into the pool area. Penguins require UV light to maintain their natural biorhythms. This was an energy conservation challenge because once UV rays enter the space they can lengthen to create infrared rays—which will produce heat. The skylights were designed to limit infrared rays using long solar tubes and adding a scrim help disperse the UV rays. This limits the amount of possible infrared rays.
However, allowing in the UV rays means the space has a higher than normal solar heat gain coefficient. This could increase the mechanical cooling unit loads and increase energy use by the mechanical systems to cool the penguin habitat space, but since penguins are flightless birds, the space only needed to maintain proper temperatures up to 7 feet above the floor. Because only the first 7 feet above ground and pool level has be at 37 F, the temperature of the air space within the penguin habitat is stratified. This facility is very cooling intensive. In order to be energy-efficient the design had to limit the need to cool, and the interior walls are part of the solution.
The interior walls are designed to maintain two distinct climates/temperatures. Staff and visitors experience 68 to 72 F, depending on the time of year. The penguin habitat stays at 37 F all year, including the water in the deep pool. There are animal husbandry rooms within the staff/maintenance area that can be set at a wide range of temperatures—from 37 to 72 F. These rooms are used for incubating the penguin eggs (warm) and gradually acclimating the young birds to the colder temperature of the main penguin habitat (warm to cool).
Insulated walls separate all the different environments within the building. The penguin habitat is separated from the rest of the building using a CMU cavity wall. It is set with 2.5 inches of foam-in-place insulation, including above and below the wall cavity. This provides the same R-value between the penguin habitat and the visitor’s spaces below the pool (Figure 2).
The interior glazing is acrylic because of its higher thermal performance compared to glass. Some acrylic panels are as thick as 9 inches. Acrylic was used for both the pool and above ground viewing areas to limit the heat transfer between the two environments.
The pool floor and walls are insulated for a broad range of conditions. In some locations, the insulation is between the pool and interior conditioned spaces, and in others it’s between the pool and an exterior wall. The insulation and vapor barrier relationship is also unique depending on location; the vapor barrier placement varies in each temperature zone, but is typically placed on the warmer side. Because the penguin habitat is always cold and the dew point varies with the weather/seasons, the vapor barrier in this location is at the midpoint of the insulation.
The Building Enclosure
A building’s exterior is similar to skin on the human body. It protects all of the building’s internal systems from the outside world. The building “skin” includes both the vertical (wall, windows and doors) and horizontal (roof and slab) systems encasing the building. The building enclosure system plays an important role in how much energy a building uses.
Thousands of custom metal scales cover the exterior skin of the PPCC. The layered-envelope system functions similarly to the penguin’s coat of feathers. Based on their anatomical coat, biomimicry inspired the design. The final design solution was based on benefits to the penguin habitat and cost value, which included energy savings and the actual cost.
First, for the PPCC and any high-performance building, it’s very important to evaluate all the different types of building envelopes and how they impact energy performance. In this case, insulated metal panels, a rainscreen option, CMU, brick facades and many others were evaluated. An insulated metal panel back-up wall and a CMU back-up wall were evaluated. Energy calculations were performed on all options. After completing the evaluation, it was determined that the best choice was a system using the insulated metal panels with a rainscreen back-up wall. The design used sheathing and metal studs to support the insulation. Next, the type and depth of the insulation and its location were evaluated. For example, the team asked questions like, “Where should the insulation panel be located?” “If we included foam-in-place, where would it be located?” and “Do we use mineral fiber or some other insulation and where is it located?” After this series of analyses, the vapor barriers and their location were evaluated—again continually looking at the impact of each design scenario on energy usage and achieving penguin habitat criteria. During the entire design process, the goal was to create a vapor and airtight envelope.
This was accomplished using sheet membranes and sealants. The insulated metal panels work as both a vapor and an air barrier in a rainscreen application. Selected as the best solution, it met the high-performance goal of longevity and durability. With two distinct temperature environments, this system best controlled vapor. Dew point calculations were run and showed that in both environments … cold in the penguin habitat and hot or cold on the outside … warm in the visitor/staff areas and hot or cold on the outside—the dew point was never in the danger position. This design helps avoid maintenance issues within the building.
To protect against thermal transmission, the entire foundation was encapsulated with a vapor barrier, water proofing and insulation. The 300,000-gallon penguin pool is 24 feet deep and because the water is kept at 37 F, it was imperative to protect it year-round from thermal transmission from the surrounding soil. In addition to the cavity wall around the foundation, shotcrete in conjunction with insulation was used at the perimeter to protect against thermal transmission.
Five different wall types were used in the PPCC enclosure design, depending on their location and the user—penguin or human. A basic wall design was determined and then modified depending on the location. The layered rainscreen wall design is comprised of metal panels as “shingles” with a 1/4-inch air gap. Then there is a peel-and-stick waterproof member that self-heals around the anchors to prevent any thermal or vapor transmission. Finally, this was all installed over 4-inch insulated panels.
The wall works even when the panel heats up in the sun. The 1/4-inch air gap, present from bottom to top of the wall, uses stratification to naturally carry the heat up to the top and then dissipate out. This prevents the waterproof membrane and insulation panels from heating up too much in warm/hot weather and keeps the penguin habitat cool. The five types of walls and where they were used are:
For the main penguin habitat, the walls were composed of:
• Exterior metal wall tile
• On underlayment material
• On 4-inch insulated metal wall panel
• On steel girts
• Waterproofing membrane
Walls above the roof were composed of:
• Exterior metal wall tile
• On 1 1/2-inch metal wall panel
• On steel girts
• Waterproofing membrane
Walls below the roof in the staff areas to the back (north) and the west and east walls were composed of:
• Exterior metal wall tile
• On 1 1/2-inch metal wall panel
• On CFMF girts
• On 2 1/2-inch foam-in-place insulation
• On 8-inch CMU (or concrete wall at trickling filter)
• Waterproofing membrane
Walls on the north side in the staff areas were composed of:
• 4-inch burnished CMU
• On 2 1/2-inch foam-in-place insulation
• On 8-inch CMU (or concrete wall at trickling filter)
• Waterproofing membrane
And lastly, the parapet walls that shade the roof over the penguin habitat were composed of:
• Perforated corrugated metal panel with vertical flutes on steel girts
• Waterproofing membrane
Figures 3 and 4 show cross-section designs of two wall types. Figure 3 shows the enclosure at the lobby and above the penguin habitat. On the lower portion, there is glazing and an overhang to prevent heat gain in the summer months. The overhang is insulated with the tile wall, an air gap and the metal panel. Once the wall goes above the roof (upside down V shape), that portion is either metal tile on the panel or just a metal panel. This wall design helped determine the shape of the roof over the penguin habitat to prevent heat. Even though the roof is white to reflect heat, it needed to be shaded to limit the heat gain on the roof and minimize the need to cool.
Figure 4 shows the north or back side of the facility where the staff and animal husbandry rooms are located. Here is the CMU wall with insulation plus another CMU wall. There are two walls in this section. The animal husbandry rooms had to be separated from the rest of the staff area because the temperature in these special rooms must range from 37 F to the 70s depending on how the room is used—either to incubate the penguin eggs or acclimate the young birds to the cold habitat environment.
Other Enclosure Elements
Glazing was limited to the south face of the PPCC. It’s a typical 1-inch glazing unit with low E coating with low reflectivity, bird strike prevention and fritting. This helps limit heat gain, as well as prevent birds from hitting the building. Also, the building shape itself shades the glazing.
Skylights were required to provide the penguins with UV light. In order to limit the heat gain from the skylights, they slope to the north, limiting the amount of direct sunlight. They vary in depth to limit heat gain. The scrim diffuses the light and decreases the amount of harmful infrared rays entering the penguin habitat.
The roof is white thermoplastic polyolefin single-ply membrane with 8-inch minimum tapered insulation, vapor barrier and sheathing. It has the continuous insulation that is used throughout the entire building including underneath the slab. In a typical zone, the vapor barrier is located at the bottom of the insulation. But the penguin habitat zone was handled differently. Based on dew point calculations, a 4-inch vapor barrier is used above the insulation to prevent a dew point from the interior ceiling space above the animal habitat. This was necessary to avoid water dripping from the ceiling and potentially harming the building materials. Dew point calculations are very important in determining the placement of the vapor barrier.
The Wrap Up—Conclusion
When designing a high-performance building enclosure there are several key things to remember:
- Continuous insulation and air barriers will help you create a high-performance building, but they must be properly located. And don’t forget about the ground. As in the PPCC, with a pool you must prevent heat transmission from the ground.
- You must always identify and design for the unique functions and features of the building. Look at the primary building use, but every building will have unique features and you must understand how they will affect overall building performance.
- Use passive design as much as possible. This helps limit the initial costs of the mechanical units and their operational and maintenance expenses, as well as energy-use costs.
- Don’t forget about commissioning and metering properly. If this is not done thoroughly and accurately, you will waste more energy than you should. The additional cost of installing the right number of meters up front will be returned multiple times in energy-cost savings over the life of the building. BE
Anthony Offak is a registered architect in Michigan, holds a Bachelor of Architecture degree from University of Detroit Mercy and is a member of USGBC Detroit Regional Chapter. He joined Albert Kahn in 2000 as a Project Manager for the firm’s Automotive/Industrial team. His background in tracking and management of data is foundational to his contributions to the firm and his roles as project architect and project designer. His oversight of 3D BIM integration into projects combined with commitment to sustainable practices in building design are some of his many contributions to Kahn. Most notably he has been involved with multiple LEED projects, some that were pioneering projects such as the first LEED Gold Hospital in Brazil and the first LEED Silver Hospital in Wisconsin.
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