Pros & Cons of Passive House Construction
Today, advanced technologies have created a more sustainable design for energy efficiency. Passive houses are improving the quality of life for homeowners.
The key value of a passive house construction is its ability to heat and cool buildings cheaper without any loss of comfort. These buildings can operate using 75%-95% less energy compared to traditional power methods. However, there's more to consider when analyzing the pros and cons of passive house construction than just energy modeling.
The reason for these large energy savings is the building materials and the transfer systems. The materials actually capture the sun’s heat within its own airtight construction. There’s no need for solar panels to convert the energy to power. The insulation is continuous throughout the walls, floor, and roof with no gaps. Added to the building specifications are energy-efficient windows and controlled ventilation. Combined, these components regulate the inside environment, maintaining a constant temperature.
The design fits any size building, whether it is custom built or renovated. In some cases, an existing building may have recyclable materials to help lower the construction costs. Building standards for passive homes are compliant to U.S. energy efficiency codes for all construction projects. These buildings are designed for building owners and constructed to the variances of climate and nature that exists in the locale. The systems can be capable of producing renewable energy to sustain a building over the course of the year. Passive homes are designed to provide comfort to fit a tenant’s indoor lifestyle, which is accomplished with fewer temperature fluctuations. Temperature stability is yielding owners significant savings on the cost of utilities.
Energy Modeling provides insight into how your building uses energy. This allows for the opportunity to run multiple scenarios to lower both construction and energy costs.
Pros of Passive House Construction
Imagine living in a building with no cold drafts and a constant temperature in all of the rooms year-round. Passive house construction offers a healthy living environment without heating or cooling bills. The green technology during the past years has created energy-efficient homes for year-round living. These new passive applications using insulation and mechanical systems are replacing the old costly heating and cooling systems. The systems now direct heat or cooled air to a specific room rather than dispensing it to the entire building.
- Thicker walls offer more heat retention.
- Insulation creates a sound barrier for quiet.
- Results include reduced operational costs.
Advantages of a passive house include higher air quality and consistent interior temperatures. The design includes an energy recovery ventilator. Ventilators adjust the air daily depending on the number of people and activity levels in the building. Basically, it pushes the stale air out and draws in the fresh air. In winter, heat from exhausted air is transferred to the incoming cold air. In the summer, heat and humidity are drawn from the incoming air and transferred to the outgoing air.
Passive house benefits include:
- Long-term cost savings using energy efficiency.
- Systems need minimal space in the design construction.
- Integrates with hot water heating system.
Passive house construction allows a variety of energy efficiency options meeting the owner’s wishes. One example is a large window with a panoramic view. The construction and design can prevent the loss of heat due to the large window surface. The solution is to add extra wall or roof insulation to the surrounding areas. Owners need to work with an experienced contractor to ensure all details for building a passive home are included in the planning. There's no reason not to have the home of your dreams.
Cons of Passive House Construction
The lack of consumer knowledge is a major drawback for passive house construction. That’s the sad news, since so many owners struggle to maximize a home’s use of energy. One issue is a harsh winter, which is known to reduce the building's heat. The reverse action of cooled air loss can happen with prolonged high exterior temperatures. Some locations need more insulation for ample heating and cooling. High energy rated windows and seals can prevent the heat and cool air from seeping out. Supplemental heating and cooling system as a backup may be needed to help through difficult seasons. All of these conditions have viable solutions and may increase the cost for construction.
- Initial costs can be 10%-30% higher with new or renovated construction.
- Weather conditions can alter performance.
- External conditions make a difference in design.
The initial design and construction costs can be higher, compared to a traditional building. For instance, the outer wall thickness will vary depending on the site. The design is dependent on the location and weather conditions. Owners need to consider the utility savings against the cost of passive building materials. The cost recovery begins immediately once the building is occupied. Like all new features in a building, there’s a learning curve for new owners.
- Occupants need to learn how to operate controls.
- A back-up heating system may be needed.
- Potential thermal bridging threats exist.
Thermal bridges can exist in the walls, floor, and the roof in all home designs. A thermal bridge occurs when the insulation layer is displaced, creating heat pockets. These pockets can cause uneven air distributions. The problems can be prevented when working with an expert in the design and detailing of the home.
The bottom-line, passive house construction does reduce the costs of heating and cooling. Technology teamed with construction offers an inclusive design using the sun’s natural light and heat. There will always be a compromise between the past developments and the current improvements. Working with a design expert reduces the potential disadvantages and increases the benefits. Lasting values to building a passive home are:
- Durable buildings
- High air quality
- Energy efficiency savings
About Michael Tobias
Michael Tobias, PE, LEED AP, CEM. Michael Tobias is the founder and principal of New York Engineers, an Inc 5000 Fastest Growing Company in America. He leads a team of 30+ mechanical, electrical, plumbing, and fire protection engineers from the company headquarters in New York City, and has led over 1,000 projects in New York, New Jersey, Pennsylvania, Connecticut, Florida, Maryland, and California, as well as Singapore and Malaysia. He is a graduate of Georgia Tech class of 2004, with a Bachelors of Mechanical Engineering with honors. His innovative approach to MEP engineering comes from graduating GE’s Engineering Leadership Program, where he designed wind turbines and biofuel power plant engines. Michael’s passion within design is energy efficiency and green technology. His focus is on integrating MEP/FP engineering design with architecture to create as seamless a system as possible. He is an advocate for green design and technologies, and has designed to both Passive House and Net 0 energy standards. He has spoken numerous times at the AIA, been featured in Georgia Tech’s Alumni magazine, and is an engineering expert on Discovery Channel’s show “Impossible Engineering”. A New York native, Michael grew up in Rockville Centre, LI. He currently lives in Brooklyn with his wife and children. Outside of work, he enjoys exploring the outdoors, whether it’s on a bike, a pair of skis, or a surfboard. He is passionate about growing personally and professionally every day, and about doing innovative work in the engineering world to help disrupt the traditional construction industry.