Ever wondered if you can create a building that offers both comfort and energy efficiency? Here comes the concept of passive building which was developed by the Passivhaus Institut in Germany in 1996. In this blog, we will discuss what is passive house in detail and explore its benefits, disadvantages, and cost.
What is Passive House?
It is a building that meets the criteria of the passive house standard, which was developed by the Passivhaus Institut in Germany in 1996. The criteria include the use of passive sources of energy, such as solar radiation, internal heat gains from occupants and appliances, and natural ventilation, to regulate its climate. They also use renewable energy sources, such as solar panels or heat pumps, to provide any additional energy needs.
There are five principles based on the passive house standard:
- High-quality insulation: The building envelope is insulated with thick layers of material that prevent heat loss or gain.
- Superior windows: The windows are double or triple-glazed with low-emissivity coatings and gas-filled spaces that reduce heat transfer.
- No thermal bridging: The building structure is designed to avoid any gaps or weak points that could cause heat loss or gain.
- Mechanical ventilation with heat recovery: The building has a ventilation system that constantly exchanges fresh air with stale air while recovering the heat or coolness from the outgoing air and transferring it to the incoming air.
- Airtight construction: The building is sealed with tapes, membranes, and gaskets that prevent any air leakage.
What is Passive Building?
Passive building is a broader term that encompasses what is passive house and other similar standards, which aims to create buildings that are energy-efficient, comfortable, and sustainable. Passive building is based on the same principles as passive house but allows more flexibility in terms of performance criteria and certification methods. Some examples of passive building standards are:
- MINERGIE-P: It is a Swiss standard that is similar to passive house, but has slightly different requirements for space heating, primary energy, and airtightness.
- PHIUS+: It is a North American standard that is based on passive house but adapts to different climate zones and cost-optimization factors.
- LEED: It is a global standard that evaluates the environmental performance of buildings based on several categories, such as energy, water, materials, indoor environment, etc. LEED also features different levels of certification ranging from certified to platinum.
Passive House Energy Consumption
One of the main goals of this design is to reduce the energy consumption of buildings, especially for heating and cooling. Passive house only needs an additional renewable source of energy for heating such as solar when the weather is very cold, while in hot summer months, air conditioning is unnecessary as insulation keeps the heat out.
A house requires around 15 kWh per square meter of surface area of heating energy. The total energy needed for all domestic applications in a passive house does not exceed 60 kWh/m² area, which is less than half of what a typical house requires.
Also Read: 10 Features of a Sustainable House
What are Passive House Benefits?
Passive house benefits more compared to conventional buildings in many ways, such as:
1. Lower energy consumption and bills: These buildings can use up to 90 percent less energy than typical buildings, which translates into significant savings on utility bills and reduced greenhouse gas emissions. Saltbox Passive House in Canada features superior double or triple-glazed windows with low-emissivity coatings and gas-filled spaces. The windows reduce heat transfer and provide natural light and views. Thus, saving energy on heating and cooling.
2. Better indoor comfort and health: Passive house benefits from consistent temperatures and humidity levels, as well as fresh and clean air, which improve the comfort and well-being of the occupants. One example of a company is Casa GG in Spain, which has a ventilation system that constantly exchanges fresh air with stale air while recovering the heat or coolness from the outgoing air and transferring it to the incoming air
3. Peace and quiet: These buildings have high levels of insulation and airtightness that reduce both external and internal noise, creating a peaceful and serene environment. Straw Bale Home in the UK is another example that features a hay bales build that is sealed with tapes, membranes, and gaskets to provide an airtight construction.
4. Value and attractiveness: The buildings have a modern and elegant design that enhances their aesthetic appeal. They also have a higher market value and demand than typical buildings. The passive house Devon Passivhaus by McLean Quinlan features a linear red-brick wall that distinguishes it from the surrounding landscape. It has a modern and elegant design that enhances its aesthetic appeal.
5. Higher quality and durability: Passive house buildings are built with high-performance materials and techniques that ensure their longevity and resilience.
These are some of the benefits which offer advantages to both the environment and the occupants of the building. As you can see, a passive house is not only a standard but also a design concept that integrates with architectural design.
Also, take a look at A Sustainable House Built Using 19th Century Straw Bale Construction Practice.
What are Passive House Disadvantages?
There are some passive house disadvantages that need to be considered, such as:
1. Higher initial cost: One of the most common passive house disadvantages is that they require more investment upfront than typical buildings, due to the higher quality of materials and labor involved. However, this cost can be offset by the lower operational costs and maintenance needs over time.
2. Specialized knowledge and skills: These buildings require specialized knowledge and skills from the designers, builders, and contractors involved in the project. They also need to follow strict standards and guidelines that may not be familiar or available in some regions or markets.
3. Limited location and design options: Passive house buildings need to be carefully designed and oriented to suit the local climate and site conditions. They may not be suitable or feasible for some locations or design preferences.
4. Internal noise concerns: Passive house buildings have very low levels of external noise, but they may also have higher levels of internal noise due to the ventilation system or other sources. This may require additional soundproofing measures or adjustments.
Additionally, check out the 6 Advantages and Disadvantages of Green Building.
How Much Does a Passive House Cost?
The average passive house cost in the US is about $85 per square foot, which is about 10 percent higher than a conventional house.
The cost varies depending on many factors, such as the size, location, quality, and complexity of the project.
- The passive house cost difference can be reduced or eliminated by using cost-saving strategies, such as prefabricated components or modular designs.
- The cost can also be compared to other energy-efficient standards, such as LEED or Energy Star.
- The cost is about 5 percent higher than a LEED-certified house, and about 15 percent higher than an Energy Star-certified house.
- The higher cost can be offset by the higher energy savings and performance over time
Passive House Vs. Traditional Houses Comparison
You may wonder what the differences between passive house and traditional buildings are if you’re planning to build or renovate your house. Passive house and traditional are two different approaches to building design and construction, with different implications for energy efficiency, comfort, durability, and sustainability.
In this section, we will compare passive houses vs traditional buildings in terms of these aspects and see which one suits your needs and preferences better. Here is a table that summarizes some of the main differences between passive house and traditional buildings:
|Energy consumption||Up to 90% less than typical buildings||Varies depending on building codes and standards|
|Heating and cooling systems||None or minimal, rely on natural sources of energy and ventilation||Active systems that consume energy and may cause temperature fluctuations|
|Windows||Double or triple-glazed with low-emissivity coatings and gas-filled spaces||Single or double-glazed with less protection from heat transfer|
|Ventilation||Mechanical ventilation with heat recovery that provides fresh and filtered air||Natural ventilation that may be less effective in managing indoor air quality|
|Noise||Low levels of external noise, but higher levels of internal noise from the ventilation system||Higher levels of external noise, but lower levels of internal noise|
|Cost||Higher initial cost, but lower operational cost and maintenance required||Lower initial cost, but higher operational cost and maintenance required|
|Comfort||Higher comfort due to consistent temperature and humidity levels and clean air||Lower comfort due to drafts and temperature fluctuations and stale air|
|Sustainability||Higher sustainability due to lower energy consumption and carbon emissions||Lower sustainability due to higher energy consumption and carbon emissions|
As you can see, passive house vs traditional buildings have many advantages and disadvantages in terms of energy efficiency, comfort, durability, and sustainability. However, they also have some trade-offs, such as higher initial cost, specialized knowledge and skills, limited location and design options, and internal noise concerns. Therefore, it is important to weigh the pros and cons of each approach before deciding which one suits your needs and preferences best.
You can also go through these 7 Best Eco Friendly House Designs.
A passive house adheres to a set of architectural guidelines that minimize the need for air conditioning and heating while maintaining healthy indoor environments. Numerous benefits come with passive houses, including reduced energy costs, enhanced indoor comfort, longevity, and greater aesthetic appeal and value. However, they have certain drawbacks, such as higher upfront costs, restricted design options, and the requirement for specialist knowledge. Feel free to explore our website for more insightful blogs and articles covering various review topics.