Your House Leaks. Period.
It doesn't matter if you're living in a state of the art home or a grass hut. Your house leaks air both in and out through the many cracks in the walls, ceilings, floors, etc. In a Passive House the size and number of cracks are kept to a minimum. In a grass hut...not so much. Either way, it still leaks.
The amount of air that your house leaks has a huge impact on the amount of energy your home consumes. In fact, it's the biggest contributor to discomfort and energy consumption in a home.
What makes a Passive House work so well is that it reduces the amount of leakage to a tiny, tiny bit so that all that comfy cozy conditioned air that you're paying for stays in and all that unwanted hot/cold (depending on the season) polluted outdoor air stays out. It's pretty simple. Keep the good air in, bad air out. Then, your HVAC system spends less time and energy to deliver that comfy cozy air. Which, in return saves you LOTS of money! Win Win!
WHAT ABOUT FRESH AIR? DOESN'T A HOUSE NEED TO BREATH?
The house does NOT need to breath...YOU do. You're the one that needs the oxygen. So, we provide fresh air through a variety of ways. The simplest, healthiest, most dependable strategy is to bring the fresh air in through your HVAC system. That way, that fresh air can be both filtered and conditioned before it enters the house.
You can take it a step further and use something called an Enthalpy Recovery Ventilator (ERV) that not only brings in the fresh air but "recovers" some of the heat and cold from the already conditioned air in the house to condition the new fresh air entering the house. This reduces the amount of work that the HVAC system has to do to condition the air. Again, reducing energy use and you lots of money.
WHAT ABOUT INSULATION AND WINDOWS?
You may have heard somewhere that adding insulation or replacing your windows with more energy efficient ones will save you 50% on your energy bills.
Well, about the only way that's gonna happen is if you don't have any insulation in the walls to begin with AND you have just holes in the wall without anything in them...just a hole. Then, it might happen. Don't worry about these items....YET!
So, what about these "3 Important Strategies"? How do you keep the good air in, bad air out, and make your home more energy efficient?
- Don't add insulation
- Don't put any windows in your home
- Don't design and install an HVAC system.
No, before you do ANYTHING else, you must:
- AIR SEAL - it can truly cut your energy bills in half if done properly.
- AIR SEAL - it's a small percentage of your construction budget (1% is the most I've seen).
- AIR SEAL - it will keep the good air in and the bad air out.
It doesn't matter what air sealing strategy you use; caulk, foam, tape, building products that are inherently tight, gum. Just seal it up. You have got to seal up and/or avoid as many cracks in the building envelope as you can. Then, and only then, do you start deciding on the type and amount of insulation, windows and HVAC system and everything else that goes in to improving the performance.
There is only one other thing you want to do before air sealing...have a plan. Have everything designed and/or mapped out so that whatever you do with your home (air sealing, windows, HVAC, overhangs, etc.), it all works together...as a system. Avoid conflicts AND headaches during the construction or remodeling process. Have it designed!