At just past the framing stage on Sean's personal residence he decided it was time for us to get out from behind our desks and get our hands dirty! We had long since planned to assist in the build of Sean's home so as to better understand the construction process in order to improve our working drawings. The time has now come and it was a great change of pace! We worked on the rain screen on his home which was explained in detail in our last blog post and will be back in two weeks to continue our work!
Part 2: What it means to be Net Zero and how this will be achieved in the Hegstad Haven
There are many defining factors that go into creating a Net Zero home, today we will take a deeper look into the home's exterior walls. Firstly you need to create an efficient envelope, this is done with the use of extra insulation, thicker walls, and the reduction of thermal breaks throughout.
To get the higher quality envelope we made a thicker exterior wall, however, we needed to make the construction as affordable as possible. In order to meet this goal we first started with you typical 2x6 exterior stud walls at 16" on-center, as framers can build these walls efficiently. On the exterior side of this wall we have added 2x4's running horizontally at 2' on-center. By adding these we have given added protection against thermal bridging on this portion of the envelope. Next we added a Zip-System sheathing to the exterior instead of plywood and building wrap, doing this does not give added R-Value, but instead gives a much higher resistance to any water penetrating through this layer as the sheathing is factory coated with a water proofing membrane. On the exterior of the Zip-System there will then be a rain screen for added protection against moisture becoming entrapped within the walls. The rain screen also helps to further reduce thermal transfer and since it is very simple to construct it does not have a nominal effect on the overall cost. Finally, there will be hard board added with wood siding to complete the exterior finish. Overall this will make the exterior walls approximately 8 3/4" thick, not including interior drywall. Now, prior to adding the interior drywall the cavity of the wall will be filled with High-Density Cellulose. This was chosen over traditional fiberglass insulation for several reasons, one being that spraying in the insulation coats the 2x6's and 2x4's and all their joints, which is where the majority of your thermal bridging occurs. Another reason for choosing High-Density Cellulose is that it is only 4 PSF. Typical fiberglass insulation is heavier and eventually starts to sag under it's own weight, creating entirely uninsulated cavities at the top of your walls! Lastly, it is made of, up to, 85% recycled materials, helping to reduce the overall carbon footprint of the new home. All this forward thinking will bring the envelope of the home to an insulation value of R-27, rather than the standard R-21, making the exterior envelope of the home very well insulated with little to no thermal breaks and little to no chance for moisture to become entrapped in the walls, which is of extreme importance in our moist climate!
Part 1: So we’re just going to start from the beginning, the very beginning.
In the beginning God created the Heaven’s and Earth… and then God said “Let there be light” and there was light. God saw that the light was good…
Okay, so maybe we don’t need to start quite that far back, but still, light would be what started this project and many others like it, which we will delve deeper into in the next part of this series.
Sean and his family had been living in their custom home that Sean had designed out on acreage in Ferndale. Well, since building their home in 2008 their needs had changed significantly. They were now looking at selling their home with the goals of building their new home closer to school and work, reducing their mortgage, and designing and living in a Net Zero home. This would significantly reduce their travel and monthly expenses and allow their money to go toward other goals. As part of their mortgage reduction goal they had decided to fit their new Net Zero home into a $300k construction budget with an additional cost of approximately 35k for the solar panel system. And they did it!!!! In the end Sean and his wife Jaimi purchased a reasonably sized and priced lot in NE Lynden that is much closer to their children’s school, a more reasonable commute for Jaimi to work, and closer to their extended family, but unfortunately a little more of a commute for Sean, but hey, not everyone can just walk through their yard to their office! And! Although the overall size of their home is reduced, it’s still a very well planned use of 1,948 sq/ft, and Sean, being the space planning genius he is, was able to fit an additional 588 sq/ft 1 bdrm. apartment (ADU) above their garage in what would have otherwise been lost space. Now this space, once rented out, will be used to reduce their monthly mortgage expenses by nearly 50% and more over time instead of just being attic space!
It can be hard for some to imagine when looking at a raw piece of land the immense amount of changes that will be going on there and before you know it a whole new house is constructed, but for Sean, Jaimi, and their 2 kids, when they found their spot they were able to each stand on a corner and imagine this as their new Haven. The ground was broke this last week for their foundation, which was so satisfying to see as they had, had the pleasure of being able to stake out their home site themselves and really have that “moment” with their family when you stand back and get to truly build that excitement as you take that last look before the plunge!
Home site all staked out and ready to go!
Freshly dug foundation!
Part 2: What is means to be Net Zero and how this will be achieved in the Hegstad Haven