How to Build a Passive House – All you Need to Know

In a survey conducted by EAI released in 2016, a single household here in the US consumes an average of 897 kWh on a monthly basis. That means families could be paying as low as $75.96 to as much as $146.09 for electric charges alone. Wouldn’t it be amazing if we can cut that expense in half or even more? Well, it is not impossible if you will build  passive house.

Can you picture your house having no heating or cooling units – yes, the machines in the house that uses most of our electricity? Some of you might say no thinking that you’ll die during temperature surges. If that’s the case, you will definitely need to read further to discover what we call a passive house.

Passive House, Defined

what's a passive house

This is becoming a hot trend nowadays in the world of engineering and architecture but let me tell you that this started almost 2 decades ago; in 1991 to be exact by a physicist, Dr. Feist.

The concept behind a passive house is that proper set-up, materials, mixed with the fundamental concepts of physics; we can build a house that has a regulated temperature all year long without the aid of fireplace and air-conditioning units. This is achieved through proper insulation and ventilation.

With that being said, a laborious building standard was created in line with this. This gave contractors certain criteria to check energy demands, materials, and the principles of building a passive house. These points should be met so that the building can be certified.

Benefits of Having a Passive House

Although it might have started in Austria, the concept of passive houses is renowned all over the world; with economically powerful countries being its biggest advocates.

  • Saves a lot of money in the long run – no ac, no heaters equals lesser energy consumption equals lesser money being shelled out to pay your bills. Aside from that, the rays of the sun can be maximized. Meaning, you can switch off lights in rooms during daytime because the windows are strategically placed.
  • Passive houses are adaptive to climate. This means that you do not have to worry in case your typically hot locale goes icy.
  • You help build a better future for the next generation by installing energy efficient spaces with lesser pollution-causing footprints.

Things You Should Consider when Planning to Build a Passive House

Check Your Budget

check your budget

The building may necessitate a hefty amount of money upfront. Yes, it is more expensive. Consider the idea of needing a three-paneled window versus the ordinary ones, the price can double, or even triple depending on the merchant. That’s not all, you also need specialized sealing. Do not forget that specific paddings on walls and ceilings will also be installed to maintain proper insulation.

Generally speaking, it is advisable to apportion 5-15% additional expenses compared to a typical house. Again, this might be intimidating but I am telling you, you will be reaping great rewards from this investment eventually.

Check Your Time

If you are wondering if there’s a difference between the construction time of a typical house and a house that will meet the passive house standards, the answer is no. Basically, the same schedule can still be followed. The alteration will take place during the designing and conceptualization process.

Check the Location

In doing so, you have to account multiple issues. Primarily, you have to understand that due to the different climate zones in the world, you cannot simply make use of one single passive house blueprint. Nonetheless, the principle of passive houses can be applied wherever – even if the location experiences extreme temperatures.

In addition to that, the shading of your house and the rising and setting of the sun will also be well-thought-out before designing (placing windows for example).

Lastly, where do you plan to construct? Is it near the ocean? On dry fields? In the city? These venues will also necessitate the deliberation of materials that you will utilize.

Check the Weather

check the weather

Tropical countries have different demands compared to those with colder climates. Factors such as insulation, ventilation, and even the placement of windows need to be modified accordingly. A passive house building aims to set the heating load to a maximum of 10 W/m2. Technically speaking, that’s easily achievable in the localities of Singapore, Shanghai, Dubai and even here in Vegas; but not in Sweden or Alaska.

Designing a Passive House

Hopefully, you are not confined to the idea of a design that looks like igloo, spacecraft, or a hipflask – though the principles are fundamentally the same.

Here are some supplementary words of advice I have collated from experts:

  • Your wants may not always be carried out; consult professionals to save time, effort, money, and emotional roller-coasters
  • Sometimes, the problem goes with the distribution of heat. Anticipate and correct any errors as early as possible.
  • The designer will prioritize, insulation, placement of window, sealing, types and location of the thermal mass, and available cooling and heating system. Do not be shy to ask and contribute.

Passive House 101 and Materials to Utilize

Design

Architects use different strategies (direct, indirect, and isolated gain design). These approaches are used depending on various factors:

  1. The direction of sunlight entering the house
  2. Types of walls or floors that absorb and trap solar heat
  3. Availability of solarium or sunspaces specifically for using isolated gain design

In direct gain design, water-filled containers are used to catch solar heat for future use. Water thermal storages serve a different purpose which cannot be effective in indirect gain designs, thus a Trombre wall, which is an 8×16 inch thick masonry wall and a 2-layered glass wall are used instead. Take note that whatever design is selected, it should follow the space heating and cooling demand and thermal comfort criteria for the certification of Passive House.

Roofing

Two systems are used in building roofs. The first one is what we call block cavity. Although the design might be flawed, the level of its air-tightness is high but not perfect because the junction in the walls and ceiling can leak air. As you can remember, it is vital to secure the air from going in and out when making passive houses.

The second system is the use of timber frames. Contrary to the above mentioned technique, it is not completely airtight and the insulation needs improvement. Carpenters should ensure that the joint of timber frames are effectively sealed to correct this.

If you are to rely on the Passive House criteria, there should be no more than 0.6 air changes at 50 Pascal pressure every hour to consider that the house is airtight.

Air Ventilation

An efficient ventilating system is one of the key factors in building passive houses. First and foremost, since the house is airtight, you need to understand that polluted air (coming from the kitchen, toilet, and indoor garage) is constantly being vented out of the house. On the other hand, your family members enjoy the fresh air as it is delivered to bedrooms, living area, and working stations. To make this work, the household can use a simple exhaust fan. Regarding the temperature, counter heat exchangers can be utilized.

Pipes. vents, and valves should be well planned-out before installing so that you would not have to redo the entire set-up. By standards’ criterion, there should not be any excess of 120kWh (per usable living space) primary energy demand every year for your domestic applications.

Windows

passive house windows

As previously mentioned, instead of using dual-pane ones, a passive house must have three-pane windows. What you should be after is that the complete window must have a U-value of 0.80-0.85W depending on your location’s climate. The window should be properly sealed and insulated. Aside from that, it could also have a glazing that can tolerate high total solar transmittance.

It is recommended that the window with the biggest surface should be directed to the equator; this is for the reason that you need to capture sun’s energy. Window frames should be minimal so that you will not be losing heat needlessly. Windows not facing the equator should be shaded to avoid overheating.

Summary

Since the countries who can really pay for their electricity costs are switching to passive houses, it means that the remunerations from this far outweigh the disadvantage. Imagine all the money you can save. Think about helping the environment heal. Dwell on the fact that the house you are building can now tolerate climate changes.

When you decide to build your own passive house, you should not forget salient elements. Here’s a checklist provided to help you evaluate the house you are building:

  • Is there a need to correct the insulation of any of the rooms?
  • Are there air leakages in any part of the house?
  • Are there unnecessary thermal bridges?
  • Are the windows properly installed, and shaded?
  • Is the roof airtight?
  • Are the certification criteria for passive houses met?

Thank you for reading. Please share this article so that more people can gain awareness about what a passive house is, what the benefits are and so that they can have an idea how to build one!