Over the course of the last couple of weeks we have discussed the upcoming changes in the Washington State Energy Code, that takes place on July 1st, 2016.
So far, we have talked about the categorization of homes being in the small, medium, and large and how many points each size needs to meet. Along with the size of the home, we have also talked about the first out of six changes. The last article discussed the wall assembly and what is inside of the wall sandwich.
The second code change reduces the amount of Air Changes per Hour (ACH) any home is allowed to have. This is essentially the measurement of how many times the air in a home is replaced on a per hour basis, in simpler words, ACH measures the air leaks in the house. This is done through the blower door test, which in most areas must be done for a home to receive final occupancy. The lower your score the better sealed your home is from air loss, so in this case, the higher the score the worse off you are.
Currently, in order to receive minimum points, the builder only needs to score 4 or below. With the code changes an ACH of 3 will now be minimum points which is increasing more difficult. However, the major difficulties would be to reduce the air leakage to 2 which would be a full 1 point, and the hardest would be to receive an ACH below 1.5 which would earn 1.5 points. The majority of homes today fall into an ACH between mid-3.0’s to low 5.0’s. Using those numbers as a comparison shows the code is trying to create a tighter more efficient home with less air leakage.
Next week we will discuss the next code change about HVAC systems and how it may affect your next home.
I hope this helps and thank you for reading Ask The Builder and making The Columbian of Vancouver, WA a part of your day.
Please submit questions to firstname.lastname@example.org. Jon can be reached direct at 360.907.5800