Building a Greener Future: Techniques for Energy-Efficient Construction

Over past decades, the increasing number of commercial spaces in the United States has led to a rise in energy demand, highlighting the need for constructing buildings that are energy-efficient. The Office of Energy Efficiency & Renewable Energy states that commercial buildings in the U.S. consume 35% of the nation’s electricity and are responsible for 16% of its total carbon dioxide emissions. Developers and building owners should be mindful that any structure constructed today will last for the next 50 years or more. And hence, adopting green practices in new construction and decarbonizing existing structures is instrumental in our efforts to combat climate change.

In this blog, discover the top energy-efficient techniques for site selection and building design, and how to utilize renewable energy systems and building automation systems to minimize your carbon footprint. Moreover, find out the widely recognized green building certifications and standards established for commercial properties.

Why Invest in Energy-Efficient Construction?

Investing in energy-efficient technologies not just helps in accomplishing corporate, social, and environmental responsibility, but also comes across as a smart business move. Commercial property owners and managers can increase their asset value by lowering their operating costs, maintenance, and energy bills (average savings of up to 25%). It’s a sure-shot way of attracting more tenants quickly, reducing tenant turnover, and ensuring high rents.

Indoor environmental quality (IEQ) of workspaces can affect employees’ physical and mental health through extreme temperatures, insufficient ventilation, poor air quality, and improper lighting. Energy efficiency measures that include installing insulation, heating, and ventilation systems as well as weatherization procedures can improve a space’s thermal comfort. Further, working in greener buildings gives employees access to improved air quality, eliminating allergies, asthma, and other respiratory ailments. This promotes the health and productivity of employees while simultaneously elevating the profile of your company in the industry.

On top of this, the Inflation Reduction Act of 2022 allows a tax deduction of up to $1.80 per square foot for commercial building owners or system designers that demonstrate a 50% reduction in energy usage achieved solely through improvements to the heating, cooling, ventilation, hot water, and interior lighting systems. Partial deductions of up to $.60 per square foot can be taken for qualifying measures. Undoubtedly, investing in energy-efficient construction goals highly contributes to turning a business into long-term viable, sustainable, and futuristic.

Energy-Efficient Construction Techniques

Commercial construction firms can develop energy-efficient buildings by opting for the latest sustainable techniques and green alternatives. Let’s take a deep dive into each and understand their impact on every aspect of a construction project.

1. Site Selection and Planning

Decisions related to the siting, massing, and orientation of buildings are fundamental to optimizing their later design process. These early-stage strategies set up the opportunities and limitations for site development and green space allocation.

• Site Location

The ideal building location will be able to handle the solar influences of the site and balance the earthwork while maximizing the functionality and aesthetics of the site. Keep in mind that the location you will select for your commercial building will have significant implications for its heating and cooling costs. In northern areas, situate buildings on the portion of the site where it receives maximum hours of sunlight. Allow for adequate distance from neighboring properties to avoid shading due to future development. Though contractors and designers have little power over the architectural shape of the building, they should aim for constructing a square building on a north-south axis and an elongated one on an east-west axis.

• Building Orientation and Passive Solar Design

Passive solar is a technique where a building is oriented in accordance with its surroundings to gain maximum thermal energy from sunlight. Windows, walls, and floors are built to collect and distribute solar energy during winter and reject heat in the summer. Unlike active solar systems, the passive solar design does not require electrical and mechanical devices.

While designing a passive solar building, consider window placement and size, glazing type, thermal mass, thermal insulation, shading, and other microclimate factors. Ideally, a building in the northern hemisphere should be oriented so that its longest side with maximum windows faces due south whereas the longest side of a southern hemisphere building should face due north. Make sure there are roads and lots to the east and west sides of the building to minimize wind exposure.

• Energy-Efficient Landscaping

Building designers construct an ‘energy-efficient landscape’ with the aim of conserving energy. This technique stresses energy conservation in maintenance and site operation of the landscape for the owner of the site. Providing shade by planting native deciduous trees is an effective way of reducing cooling costs by up to 25%. While planting evergreen shrubs as windbreaks can lessen annual fuel bills by 10-20%.

Impervious urban areas tend to heighten local temperatures due to surface absorption and radiation of solar heat. The resulting ‘heat island impact’ can be mitigated through reflective and insulated green roofs. These help in retaining and infiltrating rainwater. Implementing innovative wastewater systems and ‘dryscaping’ the site with native plants will ensure stormwater is treated as a resource, preventing additional watering.

2. Building Envelope Design

Creating an energy-efficient building envelope involves forming a barrier between the conditioned building’s interior and its exterior environment to lower total energy consumption. This barrier includes heat-resistant materials, highly insulated windows, airflow controls, and photovoltaic modules integrated into the building’s structure.

• Airtight Construction

Normal air infiltration and exfiltration (in and out movement) of buildings is known as air leakage. It is typically measured by air changes per hour (ACH). Air leakages caused by wind and temperature changes not only allow heat to escape and cold air to enter but also can promote condensation which leads to mold growth. According to Passipedia, unintended airflow from a gap as small as 1mm will carry 360g of water into the building envelope per day.

As air gaps decrease the energy efficiency of the buildings and increase utility costs, buildings should be as airtight as possible. However, without heat recovery ventilation the air quality can deteriorate and unsafe combustion gases can accumulate. Thus, air sealing with controlled mechanical ventilation is key to improving air quality and keeping occupants healthy.

Wet plaster on masonry construction, reinforced concrete, OSB of a suitable thickness, and specially designed airtight membranes are among the materials used to construct an airtight structure. In addition to the building fabric, components such as windows, doors, curtain wall systems and roof lights must be installed. Builders should use correct installation techniques like flashing, sealants, and insulation for continuous air tightness.

• High-Performance Windows and Doors

Most energy-efficient buildings today install high-performance doors and windows. Double-glazed windows or triple-glazed windows are two or three glass panes sealed in a single unit. These glasses are framed with uPVC, aluminum, wood, fiberglass, or other materials that highly contribute to a window’s heat loss rate or U-factor. Low-E glass and solar control glass blocks ultraviolet and infrared rays from penetrating your space without compromising on natural sunlight. This cuts the need for artificial lighting.

Exterior doors of most steel and fiberglass-clad doors have a magnetic strip (similar to a refrigerator door magnetic strip) that does the job of weatherstripping. Another option is revolving doors which are 8 times more efficient than conventional doors. Always look for the ENERGY STAR label while buying products and check their NFRC label.

• Insulation

In commercial structures, increasing insulation levels can enhance HVAC equipment performance and lower energy costs. Before choosing the type of insulation, determine the recommended R-values for targeted areas for obtaining accurate cost estimates from your commercial contractor. Here are the most common insulation materials during energy-efficient construction:

• Blanket: batts and rolls
• Concrete block insulation
• Foam board or rigid foam
• Insulating concrete foams (ICFs)
• Loose-fill and blown-in
• Reflective system
• Fiber insulation
• Sprayed foam or foamed-in-place
• Structural insulated panels (SIPs)
• Aerogel

Insulation is primarily used for thermal purposes, but it can also be used for acoustic, fire, or impact protection. When hiring a professional certified installer, ask the hired contractor about their experience in installing insulation products.

• Roofing

If you are planning to save energy with energy-efficient roofing, choose sustainable roofing materials such as metal, tile and concrete with lighter coloring for strong insulation and cooling for your building. Consider applying cool roof coatings as they drop roof temperatures by 50%. Also, it doesn’t matter if you have the best energy-saving roofing if you don’t have proper ventilation. Building ventilation eliminates chances of moisture build-up in the roofs and prolongs their lifespan. Many corporate spaces install skylights to replace electric lights and uplift the natural brightness of the indoors.

3. Heating, Ventilation, Air Conditioning, and Cooling

In commercial buildings, HVAC (heating, ventilation, air conditioning, and cooling) loads account for the highest energy expense. Installing energy-saving systems will help you better manage your energy consumption.

• High-efficiency HVAC Systems

Before selecting HVAC systems for your commercial space, assess their features, performance, and energy efficiency, as well as building design and local climate conditions. For heating and cooling in smaller commercial buildings, single-split systems work best, meanwhile, multi-split systems are more suitable for air conditioning in larger commercial buildings.

The Variable Flow Volume (VFV) provides part-load performance and zoned temperature control, saving energy and ensuring comfort. In cold climates (down to 0°F), heat pumps bring 100% energy efficiency as it moves heat instead of creating it. Other techniques like duct sealing, energy recovery ventilation, and outdoor air systems can improve indoor air quality and occupant comfort. It is found that ENERGY STAR certified light commercial HVAC equipment is approximately 6% more efficient than standard equipment.

• Radiant Heating and Cooling

Radiant heating and cooling is a type of HVAC technology that exchanges 50% of the heat by both convection and radiation with the area it is intended to heat or cool. The introduction of radiant HVAC systems decreases the amount of air required, other than dehumidification and ventilation.

Hence, buildings can use radiant ceiling systems, embedded surface systems, infrared heaters, and thermally active building systems to reduce fan energy of larger air systems by half. Energy-saving radiant systems are best applicable to tight building envelopes and commercial facilities including offices, schools, courthouses, and government properties.

• Natural Ventilation

Natural ventilation does not require mechanical systems to circulate air, making it an extremely energy-efficient technique. Besides door and window ventilation, ventilation shafts can be designed to bring a ‘chimney effect’. Passive cooling strategies can be employed to reduce cooling load and maximize natural ventilation within buildings. For example, shading devices such as overhangs, awnings, and louvers can be installed to prevent direct sunlight from entering the building and overheating it.

Plan operable windows, vents, and skylights in an energy-efficient building design to allow natural airflow throughout the structure. Architects and contractors can adapt the orientation, design, and layout of the building to harness the site’s prevailing winds and natural ventilation patterns. Note that natural ventilation rates should be at least 8-10 air changes per hour (ACH) for healthy indoor air quality.

• Heat Recovery Systems

Heat recovery systems produce fresh air indoors while simultaneously recovering stagnant air in the exhaust gas. To enable heat recovery, commercial air handling units (AHU) are equipped with rotary heat exchangers and crossflow heat exchangers. Owing to their low profile, plate heat exchangers are ideal for premium spaces.

Larger areas like factories, warehouses, and swimming pools can install thermal wheels for avoiding costly heat losses. In a commercial kitchen or hospital, run-around coil exchangers will best extract dirty or contaminated airstreams. Estimates reveal that heat recovery systems recover 60-95% of the heat in the exhaust air thereby improving the energy efficiency of buildings.

4. Lighting and Appliances

According to the Department of Consumer and Regulatory Affairs, the annual electric lighting cost of a 10,000-square-foot office building runs between $4,600 and $8,300. For small business owners who cannot afford high electric bills and maintenance costs, here are useful options for ensuring savings and sustainability.

• Energy-efficient Lighting Fixtures and Bulbs

For commercial settings that remain illuminated for long hours, LEDs (Light Emitting Diodes) are an efficient solution. Unlike incandescent and fluorescent lamps that use wires to transmit electricity, LEDs produce light through the movement of electrons. Induction bulbs, too, use less energy and have zero maintenance costs than traditional fluorescent and HID (High-Intensity Discharge) lighting.

Talking about commercial light fixtures, their selection will depend on your business needs. For example, in office environments, task lighting, desk lamps, lay-in fixtures, and recessed downlights are helpful to get direct light and reduce heat waste. Track lighting best serves theatres, galleries, or retail spaces that need adjustability. Outside commercial lights and LED warehouse lighting are suitable for storefronts, parking lots, or outdoor seating.

• Smart Lighting Controls and Automation Systems

Energy-efficient commercial lighting works best with smart lighting controls and automation systems. Installing motion detectors, dimmer switches, and automated timers indoors and outdoors will reduce your company’s utility costs. Lighting automation systems save energy by switching lights on or off as per controller’s settings. An integrated lighting automation system will require thoughtful design, a skillful contractor, and perhaps custom software.

Lighting sensors and timers are particularly useful for large-scale commercial facilities where hundreds of lights have to be turned on at business times. You can also add occupant sensors to staff-only areas where you don’t have to rely on employees to turn lights on/off. Conference rooms, restaurants, and outdoor areas can take advantage of dimmer switches to create a cozier atmosphere at selected times.

• High-efficiency Appliances

ENERGY STAR is a joint administrative program by the U.S. Department of Energy (DOE) and the Environment Protection Agency (EPA) to promote products that are highly efficient. One can find commercial, residential, and industrial electrical appliances on the ENERGY STAR energy-efficient products list. Using their product finder, you can also search for products with the lowest annual electricity (kWh). Look for systems with a high SEER (Seasonal Energy Efficiency Ratio) rating and a high EER (Energy Efficiency Ratio). There’s also a yellow FTC (Federal Trade Commission) label that displays estimated energy use and cost data for buyers to make informed decisions.

5. Renewable Energy Systems

The increasing consumer demand for green products and services has led many large corporations to set carbon-neutral goals and help reduce greenhouse gas emissions and fossil fuel consumption. The transition to renewable energy is a critical step toward the energy-efficient construction of commercial buildings.

• Solar Panels

Commercial solar panels are a grouping of multiple photovoltaic solar panels that convert clean renewable energy from sunlight into electricity. This power generated by solar cells is sent to an inverter which converts DC power into AC power, similar to the energy sent via the utility grid. Commercial inverters are available in the power range between 2.5 kW to 250 kW.

Owners can install these on the building’s rooftop or open space to power industries or offices in off-grid or remote locations. They can supply electricity to illuminate signboards, preheat ventilation, or heat water in offices and other businesses. In comparison to polycrystalline and thin-film solar panels, monocrystalline solar panels are more energy-efficient. They are a long-lasting and durable option for commercial applications.

• Wind Turbines

Windy states such as Texas, California, Wyoming, and Minnesota are favorable for wind energy generation. Wind power generation is possible through micro wind turbines, also called ‘building-integrated wind turbines’. Usually present on rooftops, modern wind turbines are available in low-noise blad designs, vibration isolators, and sound-absorbing materials to suit urban buildings. Horizontal axis wind turbines (HAWTs) and vertical axis wind turbines (VAWTs) are popular types of commercial wind turbines.

A wind turbine system first converts wind energy (blades) to mechanical energy (rotor) and then to electrical energy using an electric generator, though advanced models directly generate AC power. Wind turbines can be connected off-grid too, requiring battery storage to store surplus electricity. Since wind is free and a green energy source, it makes an incredible source of renewable energy.

Bahrain World Trade Center is an excellent example of a high-rise commercial building with integrated wind turbines.

• Geothermal Systems

Geothermal systems are highly energy-efficient for commercial buildings because they use the constant temperature of the shallow earth to provide heating and cooling solutions. Geothermal Heat Pumps (GHPs), Direct Exchange (DX), Open Loop and Closed Loop systems are the main types of geothermal systems.

GHPs systems potentially reduce energy consumption by up to 70% more than traditional HVAC systems. So, it is a popular choice among building owners. DX systems are simpler and less expensive, but not suitable for extremely cold winters. Open loop systems use a water source as a heat sink or source, ideal for areas with an adequate supply of clean water. While closed loop systems circulate a fluid through a loop of pipes, most practical for sites without any nearby water source.

The fact that most thermal solutions have life expectancy of 50-100 years, provide energy for individual zones, and allow architects design freedom, makes them a reliable energy source for buildings.

• Energy Storage Systems

Energy storage systems (ESS) are energy-efficient technology based on lithium-ion chemistry. They collect and store energy generated from renewable technologies, including solar, wind, and biomass. Among the various forms of energy storage are hydromechanical (pump hydro), thermochemical (ice/water), and electrochemical (batteries).

With commercial battery storage, owners are able to get an uninterrupted power supply, even during outages. They can utilize stored energy at peak time for peak shaving. Renewable solar and wind energy produce power intermittently. So, energy storage systems help to smooth out these fluctuations in power. Although a power grid offers the same services, storing energy can protect against changes in rates and policies.

6. Building Automation and Monitoring

As trends grow in building technology and sustainability, Building Automation and Monitoring Systems are bringing a revolution within commercial real estate. While energy costs rise every year and the demand for staff productivity remains high, smart building technologies will play a critical role in maximizing equipment performance and providing comfort to occupants.

• Building Automation Systems

A building automation system (BAS) is a centralized hub of operating building controls through digital software or apps. It’s a greener, smarter, and less expensive method of controlling a wide range of systems like electrical, mechanical, plumbing, HVAC, security cameras, fire safety alarms, elevators, and many others.

BAS allows operators to understand the root cause of breakdowns, optimize space utilization, and adjust operation times. By installing a BAS, properties can save between $0.20 and $0.40 per square foot on energy costs. What’s more, BAS-equipped properties tend to have a higher property value than those with outdated systems.

• Energy Management Systems

In larger, complex groups of commercial buildings, integration of systems operation through a single building energy management system (BEMS) offers greater control to owners and results in cost savings. BEMS enables companies to remotely monitor and control their energy systems such as HVAC, lighting, and power systems in real-time.

You can establish their hours of operation and set points according to desired performance and comfort. Moreover, their ability to record historical performance enables the creation of benchmarks and automation of reporting. It is estimated that operating BEMS can lead to 10-25% of cost savings.

• Fault Detection and Diagnostic Systems

The fault detection and diagnosis (FDD) software uses artificial intelligence, machine learning, and data analysis techniques to automatically detect and diagnose faults in the complex equipment of large commercial buildings. For example, heaters, chillers, motors, elevators, pumps, exhaust fans, etc. Such timely diagnosis assists maintenance staff ensure that buildings perform productively and efficiently.

With the Internet of Things (IoT) advancing and wireless sensors becoming more popular in buildings, FDD has been applicable in vital fields like aerospace, automotive, manufacturing, nuclear, and national defense. Approximately 4–5% of national energy consumption can be saved by fixing existing commercial building controls.

7. Resource-Efficient Construction

Resource-efficient construction involves using sustainable construction methods and eco-friendly materials while reducing construction waste through recycling and reuse. The aim is to build environmentally sustainable structures without putting a negative impact on the planet.

• Modular Construction / Prefabrication

Among the most overlooked energy uses involves the transportation of construction materials and personnel. In modular construction, prefabricated units manufactured in factory environments are brought to the site and assembled to erect a structure.

Energy-efficient modular buildings save energy up to 67% more than traditional construction methods, reduce on-site waste by 90%, and can be 100% recyclable. In comparison to traditional construction methods, modular construction delivers more sustainability, and more value, and creates newer job opportunities.

• 3D Printing

Taking energy-efficient construction one step further, 3D printing construction is the future of net zero buildings. In 3D printing or additive manufacturing, printers extrude concrete layer by layer, mixing it with proprietary additives like clay, sand, or fiber. It enables contractors to build structures in a fraction of time with fewer workers, waste generation, and means of transportation.

Not only that, it saves energy associated with manufacturing prefabricated units, shipping them to resellers and distributing them to construction firms worldwide. Researchers at the University of Tehran have invented a novel concrete for 3D printing that produces 400 times less CO2 than conventional concrete.

• Waste Management

During the construction process, site managers should educate and encourage the project team to reduce waste production. To manage waste during the construction of energy-efficient buildings, project managers should supervise the site regularly. They should identify areas producing more residual waste and segregate recyclable and reusable materials.

Site managers should prioritize organic waste management to avoid odor and methane emissions. Accurate recording and monitoring can help analyze and reduce waste for improved waste management. Overall, all parties should be invited to participate in supporting waste reduction and incentivized with suitable rewards.

Conclusion

Commercial buildings are a significant portion of American infrastructure. Buildings are where people reside, work, and hence, they will play a key role in the transition to a zero-carbon future. With recent advancements in the construction industry, there are multiple innovative approaches available for contractors, designers, and engineers to increase a building’s energy efficiency without sacrificing its aesthetics or functionality. What we need is a sustainable mindset among building owners and developers alike to take tangible actions and set a gold standard for upcoming times. It’s when we will create a greener future for the next generation.

FAQs

What are the different green building certifications and standards applicable to commercial buildings in California, United States?

LEED, IGCC, ASHRAE, Green Globes, ENERGY STAR, CALGreen, Living Building Challenge, and WELL Building Standard.

How can building retrofits contribute to energy-efficient construction?

Building retrofits, such as upgrading insulation and HVAC systems, can contribute to energy-efficient construction of existing buildings, resulting in lower energy bills and carbon emissions.

What are the benefits of energy-efficient water fixtures in energy-efficient construction?

Energy-efficient water fixtures like low-flow toilets and faucets limit water consumption and strain on municipal water systems.

Relevant Resources:

• What is a Zero Energy Building?
• 11 Modern Methods of Construction (MMC): Application and Benefits