School districts from across the country are demanding that new school buildings be designed and constructed to deliver superior levels of performance while also providing the most energy-e cient, safe and e ective learning spaces possible – all within a strict budget. Under increasing pressure to rein in costs, meet new, more stringent building codes and reduce their environmental footprint, school districts are now at the forefront of a growing trend of energy- e cient and sustainable construction practices.
This paper will look at the design objectives, construction practices and materials essential to building new schools that improve energy efficiency while creating safer, quieter and more productive learning and social environments. It will also explain how insulated concrete block will not only provide signi cant energy conservation, but will also create more comfortable and productive learning spaces with extraordinary levels of re and storm protection for school buildings.
Districts are raising their standards for efficient systems. The building envelope is a major factor because energy codes are becoming stricter. Using the right building materials, like insulated concrete block, is key to constructing a better building envelope.
THE EMPHASIS ON BUILDING ENERGY-EFFICIENT HIGH-PERFORMANCE SCHOOLS IS A RECENT PRIORITY
From the post-World War II years until the 2000s, energy efficiency and quality of learning spaces was often an afterthought in the design and construction of new schools.
The post-war baby boom led to a surge of K-12 school building construction with more than $20 billion spent on new schools from 1949 through 19641. The emphasis of school districts during this period was to build strong, solid, durable structures that were functional, affordable and could be constructed quickly enough to meet the demand of rapidly growing communities with hundreds of thousands of new elementary, middle and high school students.
This also marked the rst time that modern HVAC systems were incorporated into the design and construction of school buildings to provide air conditioning in areas of the country where hot weather lasted well into the school year. Neither the buildings nor the HVAC systems installed to serve them were very effective at conserving energy, but it wasn’t a problem, since the energy options available were abundant and a ordable.
In the last 10-15 years, however, school districts have become increasingly committed to making energy conservation and efficiency – and the sizeable and sustained cost savings that accompany energy- e cient construction – a higher priority than ever before. Architects, engineers and construction rms that concentrate on school facilities have been striving to raise the bar for energy efficiency ever since.
Today, there is a new building boom of school construction, especially across the Sun Belt area of the U.S. where populations are exploding at a record pace. The design and construction of these schools will impact multiple generations of students, teachers, administrators and communities.
Where new school construction used to focus exclusively on cost and durability, today there are multiple issues of equal merit, including immediate and lifetime operating costs, indoor environmental quality, noise mitigation, re and storm safety, and creating the best learning and working environment for every student, teacher and sta member who will ever spend time in the building.
Even as new building codes demand unprecedented levels of energy efficiency, many schools continue to be constructed in very much the same manner that they were during the post-war building boom. The “solutions” implemented to increase energy efficiency are often just adding more and more layers of materials over existing building systems in an e ort to create a better insulated and higher performing building. Yet adding additional layers of materials requires more complex design and construction sequencing, and increases costs for the added materials and labor.
Before moving forward with the design and construction of this next wave of school buildings, architects, builders and school district administrators should reconsider which materials will be most effective in constructing energy-efficient, high-performance schools. They should compare traditional building materials with more integrated building products and systems that can meet, and even exceed the demands of new codes, while reducing the cost and complexity of construction. Understanding these options is critical to ensuring that school district administrators can make informed decisions that will impact their respective communities for the better part of this century.
OVERCOMING THE MULTIPLE CHALLENGES OF BUILDING HIGH-PERFORMANCE SCHOOLS
New schools require designs and building materials that meet the standards of today – and tomorrow.
In 2015, school district administrators know that the choices they make today regarding the design and construction of a school will have a long-term economic and environmental impact that could easily last 30, 40 or 50 years. That’s why energy efficiency is o en among the top criteria of planning for a new school.2
Energy-efficient design starts with architects that make the best use of the space available and take into account every opportunity to minimize or maximize heat gain through building orientation and envelope design in order to take advantage of local climate and weather. This includes minimizing east- and west-facing glazing to reduce heat loads on a building, and using e ective natural daylighting through the incorporation of north- facing clerestory windows or south-facing windows with proper shading to limit the need for lighting and reduce electricity costs. Properly designed shading over south-facing windows will also allow for heat gain during winter months to further reduce the need for mechanical heating.
Another major decision centers on the structural and envelope systems and building materials, which, in most cases, are interdependent. A number of criteria should be considered in selecting these systems and the materials used in the construction of a new school, including: rst costs of construction; long-term operating costs; occupant comfort and productivity; occupant health and safety; and sustainability.
FIRST COSTS: Today, many designers are trying to get existing systems up to code by implementing multiple incremental changes, essentially adding insulation and air barrier layers to concrete masonry and steel structures. This approach increases both the cost and complexity of construction, while also creating new challenges, like slowing the speed of construction, which in turn, leads to higher building costs.
OPERATING COSTS: Ensuring that a new building performs at peak efficiency starts with durable, quality construction that provides continuous insulation, thermal mass and air tightness. This requires a building envelope that eliminates air in ltration with no degradation in performance over time. It also means eradicating problems with moisture, mildew, mold, and rot. All of these factors contribute to reducing the costs of energy consumption, maintenance and repairs over the lifetime of the building.
IMPROVED LEARNING ENVIRONMENT: Research has proven that lighting, air quality and noise levels all have a measurable impact on student achievement. 3 Indoor environments designed for optimum levels of enjoyment and learning productivity are constructed to provide a number of important bene ts. These include clean air throughout the building, year-round thermal comfort, noise mitigation and natural daylighting. In order to achieve this high level of performance, buildings must be air tight with engineered HVAC systems and mechanically filtered ventilation that virtually eliminates outside pollutants and allergens. Proper building orientation manages natural light to minimize heating and cooling loads year round.
HEALTH & SAFETY: Healthy schools are clean, quiet, dry, free of dust and particulates, and have good indoor air quality. 4 While air-tight construction and well-designed HVAC systems limit outside pollutants and allergens, new school buildings should also be constructed using materials that are not susceptible to mold and mildew growth that can lead to respiratory issues for students, teachers and sta . From a safety perspective, these buildings should use materials that are re resistant and can provide storm safety that far exceeds standards. This is especially important in areas along the coastline or where tornadoes are common.
SUSTAINABILITY: In order to reduce the environmental footprint of the new building, construction must include the use of energy-e cient materials, recycled materials and regional materials that all work together to ensure maximum performance and cost-savings during the entire lifespan of the building.
UPDATING TRADITIONAL BUILDING SYSTEMS TO MEET NEW MARKET DEMANDS
Modifying existing building systems to achieve high performance standards is too often a difficult and costly compromise.
School districts are asking much more from new school buildings than ever before. Building codes are also requiring better performance with respect to energy efficiency and life safety. For these reasons, school districts are looking for materials that are more energy efficient, more sustainable (especially as might apply to LEED projects), easier to install, more functional, more reliable and durable and more cost-effective than in the past. This includes products that provide higher R-value insulation and create thermal breaks.5
This has challenged architects, contractors and building materials manufacturers to modify their building designs, construction methods and materials specifications.
The natural response to these new criteria has been to modify or add to the traditional materials and system designs in order to provide the additional performance required. Rather than start with a new system, the architecture-engineering-construction industry has found it easier to simply stick with what they have always done and attempt to make modi cations to meet the new, highly evolved performance goals.
For wall systems in particular, this has meant adding multiple layers of materials to meet each of the individual objectives. The two most common wall systems used in the construction of school buildings have been concrete masonry and structural steel with light-gauge framing.
The challenge for these systems has been addressing the insulation and air tightness required to meet the new energy efficiency goals, while also avoiding re and life-safety concerns introduced by the additional insulating and air barrier materials. Adding layers to both of these traditional systems has introduced more complexity in designing the details of a wall system, especially at window and door openings, connections to other building elements, and integration with exterior nishes. These more complex designs have also increased the amount of time and money it takes to construct a school building. More layers of material means more trades on a job site, more coordination issues as each trade attempts to accomplish their scope of work, and more labor required overall to get the job done. Adding layers of materials to increase energy efficiency results in challenging many contractors’ budgets and schedules.
The hierarchy of needs has focused the attention of design and construction professionals on meeting changing building codes rst. Wall component manufacturers have responded by providing code-compliant accessory materials that can be added to masonry and steel frame wall construction. However, many of the options stop at minimum code compliance with respect to energy efficiency and air tightness, and do not signi cantly improve the performance of the building from the perspective of re safety, storm safety and long-term sustainability.
Design teams should consider the following points when evaluating modi cations to existing wall systems like concrete masonry and steel construction for school building projects.
(See Table 1.1 at bottom for summary):
FIRST COSTS: Both concrete masonry and structural steel with light-gauge framing require additional insulation and air barrier layers, and in some cases, multiple insulating materials in an assembly. While these traditional systems have been relatively cost e ective to date, the increased number of materials and trades involved in providing a complete wall system today has made construction slower, more complex and more costly. Speed of construction and increased labor costs are signi cant challenges for these wall systems.
OPERATING COSTS: Both systems can be designed to meet the current energy codes, but are expensive in regard to achieving signi cantly higher performance than code requires. Cost of maintenance and repair for concrete masonry is good, however lightweight steel framing and cavity wall designs are still challenged in the long term with mold, rot and overall durability issues.
IMPROVED LEARNING ENVIRONMENT: With proper insulation and air barrier design, both systems can provide a reasonable level of air tightness and energy efficiency. However, it may be more di cult to achieve optimal performance from the steel cavity wall construction. Concrete masonry can provide better potential thermal comfort and noise reduction than steel construction, thanks to the insulation and thermal mass of the wall.
HEALTH & SAFETY: Again, with proper air barrier and sealant design and construction, both systems can provide a reasonable level of air tightness to reduce the in ltration of allergens and pollutants into classrooms. However, cavity wall construction is much more susceptible to mold and rot which can be compounded by more airtight buildings. For both systems, re ignition barriers must be installed over the insulation if its combustible. Concrete masonry can only provide major storm protection when fully grouted. Steel construction is not normally rated for windstorm protection.
SUSTAINABILITY: For both systems, it can be costly to achieve more than code-compliant levels of energy efficiency, but signi cantly harder for steel construction than masonry. Masonry walls also contribute signi cant weight of material to a project, while steel construction requires many different materials to complete an assembly. Neither system provides any signi cant amount of recycled materials.
In most cases, masonry may be a locally produced product. Building life cycles are usually good with masonry construction, yet only modest with structural steel.
NEW MATERIALS MAKE IT POSSIBLE TO BUILD BETTER LEARNING ENVIRONMENTS WHILE REDUCING ENERGY COSTS
Energy-efficient insulated concrete block provides immediate and long-term benefits to new school buildings.
Schools spend more on energy than on any other expense except personnel.6 Constructing an energy- e cient school is one of the best investments a school district can make. The key to that investment is building a school with materials that conserve energy, reduce costs and provide a cleaner, more comfortable environment for students, teachers and staff.
Constructing a better building envelope is critical to building a school that achieves these goals, meets new code requirements and reduces operating costs. A better building envelope starts with insulated concrete block.
“Energy efficiency in a new school starts with the building envelope. Insulated concrete block is bridging the gap in providing a continuous insulation solution that can be constructed as a single solution instead of a series of systems. This streamlines the process, reduces costs for construction, and will provide great cost savings every year as long as the school is in use.”— Manuel H. Garza, Project Manager, LEED AP Pfluger Architects
Bautex Block is an insulated concrete block used to construct schools and commercial buildings that provides thermal and sound insulation that exceeds current building codes, improves comfort and air quality, and delivers exceptional fire and storm safety – all while offering significant year-over-year cost- savings to the school district that by saving millions of dollars over the life of the building.
Bautex Block is a lightweight, modular and mortarless wall system where blocks are stacked and then lled with reinforced concrete to create an insulated structural wall. The wall system is constructed using the same labor, tools and techniques as those used in traditional concrete masonry construction. Plumbing and electrical systems are typically added a er the walls are constructed.
“The Bautex Block is changing the way new schools are built today, and how those schools will benefit their communities for the next 40-50 years. From increasing energy efficiency and reducing the carbon footprint to providing a cleaner, healthier and safer learning environment, Bautex Block will set the standard for building materials used to construct schools. Most importantly, the amount of money saved from reducing operational costs will be enormous over the lifetime of the building.”
— David Sterne, VP Sales and Business Development Bautex Systems
The result is a simply constructed, single, integrated wall assembly that creates an airtight, continuously insulated building envelope that provides substantially higher levels of performance and safety. Design teams should consider the following points when evaluating Bautex Block for school building projects.
(See Table 1.1 on last page for summary):
FIRST COSTS: Speed and ease of construction are the primary benefits of constructing with Bautex Block, which provides better building performance in a single, integrated assembly. The large, lightweight blocks are stacked quickly without mortar and are installed by a single trade using less- skilled labor than other traditional wall systems. Overall cost of installation is competitive, but the savings in project timeline can be significant.
OPERATING COSTS: Bautex Block is an energy-e cient R-14 continuously insulated mass wall that exceeds the 2015 IECC energy codes for climate zones 1 through 6 by as much as 246%7. The system is very durable with proper nishes and is not susceptible to mold, rot or degradation in performance. With Bautex Block, no additional maintenance is required over time.
IMPROVED LEARNING ENVIRONMENT: With the installation of a fluid-applied air and moisture barrier, Bautex Block walls provide demonstrably higher levels of air tightness and energy efficiency. Continuous insulation and thermal mass also contribute to a stable and comfortable indoor temperature and high noise reduction.
HEALTH & SAFETY: The air and moisture barrier typically installed with the Bautex Block system helps to eliminate pollutants and allergens from infiltrating the classroom environment. The system also provides one of the highest re safety ratings of any wall system, and meets FEMA standards for hurricane and tornado safe room construction.
SUSTAINABILITY: Bautex Blocks are exceptionally e cient in the use of materials and utilize 28% recycled materials by weight. For projects in Texas, Oklahoma, Arkansas and Louisiana, design teams can take advantage of purchasing local and regional materials. Due to the longevity of concrete construction, buildings that use insulated concrete block like Bautex Block can experience long lifecycles.
Some school districts also mandate LEED for Schools (http://www.usgbc.org/leed/rating-systems/ schools) to emphasize performance and sustainability. The desired e ect of building to meet or exceed codes, such as LEED®, is to improve energy efficiencies and maximize sustainable building practices.
Schools constructed with Bautex Block exceed current energy-efficiency codes mandated by local or regional authorities in most climate zones in the U.S., and can contribute to many of the sustainability goals for voluntary programs like LEED.
“Facility directors who run the buildings are more aware and conscientious of energy efficiency now than ever before. Districts are raising their standards for e cient systems. The building envelope is a major factor because of rising energy costs and stricter energy-related codes. Using the right building materials, like insulated concrete block, is key to constructing a better building envelope.”
—James Helm, AIA, LEED AP BD+C, Principal Randall-Porterfield Architects, Inc.
ENERGY-EFFICIENT, HIGH-PERFORMANCE SCHOOLS ENABLE SCHOOL DISTRICTS TO MAKE A SIGNIFICANT AND LASTING POSITIVE IMPACT ON THEIR COMMUNITIES
Building the most energy-efficient, safe and effective learning spaces possible is especially challenging in an environment of increasingly constrained budgets, but school district administrators and design professionals need to consider the once-in-a-generation opportunities that come with planning and building a high-performance school for their community. The millions of dollars a school saves from greatly reduced energy consumption can directed toward other high-priority needs, such as teachers, technology and more academic programs.
Increasing building performance through incremental changes to traditional building systems should be evaluated on whether these ad-hoc solutions genuinely meet all of the performance goals that administrators seek, while also taking into account any potential tradeo s such as speed of construction, life safety, initial and long-term cost, and creating the best learning environments for students over the life of the building.
Watch Bautex Systems video on how its wall system using Bautex Block can withstand storms. http://bit.ly/1IzDTEe
Watch Bautex Systems video on how its wall system using Bautex Block can provide four-hour re resistance. http://bit.ly/1OY4RcD
Read Bautex Systems Energy Efficiency Case Study and nd out how a high- performance building can be constructed quickly and cost-effectively while providing decades of extreme energy efficiency and cost-savings. http://bit.ly/1W9ab2j
1 National Council on Schoolhouse Construction, 1964
2 Texas Green Schools: More than just a passing trend. http://docslide.us/documents/texas-green-schools-more-than-just-a-passing-trend-c-denise-shaw-
3 Center for Innovative School Facilities http://www.osba.org/~/media/Files/Resources/Improving%20Education/CISF%20Policy%20Brief.pdf
4 School Planning and Management, Creating Healthy Schools http://webspm.com/Articles/2014/03/01/Creating-Healthy-Schools.aspx
5 School Planning and Management, Pleasing and Green http://webspm.com/Articles/2014/03/01/Building-Products-Materials.aspx
6 Green Your School from U.S. Department of Energy http://energy.gov/eere/education/green-your-school
7 2015 International Energy Conservation Code, Table C402.2, Opaque Thermal Envelope Requirements (Zone 1 & 2 require R-5.7 continuous insulation for mass walls).