landscaping

Wow, it has been months since my last post. We have had a busy spring planting 17 fruit trees, one walnut tree, and many drought tolerant, deer resistant, perennial, California native plants. We can't say enough about the UCSC Farm and Garden for their plant sales, pruning classes and CSA. Here is a pic of trees on the east side of the home with some of the plants in the foreground (summer is the time for brown dead grass here in California). In the pic you see 2 avocados, 2 persimmons, 2 pomegranites and a cherry tree. Each tree is surrounded by a small deer fence to keep our most frequent four legged visitors from eating all those tender leaves. The cherry tree has 4 kinds grafted onto one rootstock. Having 4 kinds on one tree saves space and spreads out the harvest. Our apple, plum and asian pear trees are also multi-graft.

Remember the rock wall Trevor built last December? We acquired about 500 square feet of salvaged red brick from Whole House Building Supply & Salvage. Our first small project was to pave the space between the porch slab and rock wall - pic below. We set the bricks in a basket weave pattern and are very pleased with the results. The remainder of the bricks will be used someday for the south patio. Thanks for reading!

Solar monitoring service

The solar photovoltaic (PV) monitoring service called PV Watch was installed last week. Click the "PV Watch" image below or in the right pane to see performance data for my solar array. Thanks for reading. Your comments are appreciated.

Blower door test

Sharon and Andy from Block Energy Design showed up Tuesday morning to do a blower door test on the home. This test determines how airtight the home is. Here is a pic of the Minneapolis Blower Door, made by The Energy Conservatory, installed in the entry of the home.

All of the other windows and doors in the home were closed. The blower removed air from the home and maintained pressure inside that was 50 pascals (Pa) less than outside. This small pressure difference caused outside air to leak into the house through any cracks it could find. We could feel a small amount of air flow by the tops of the sliding glass doors.

It was determined that 95 cubic feet per minute (cfm) of air flow through the blower was needed to maintain a 50 Pa pressure difference. This measurement along with the interior volume of the home was used to calculate a value of 0.4 air changes per hour at 50 Pa (ACH50). Air changes per hour (ACH) is the number of times per hour the volume of air inside the home is exchanged with fresh or filtered air. A value of 0.4 ACH50 indicates extremely air tight building construction. A new home that is considered "well built" will change over this much air WITHOUT a blower creating a pressure difference. All of that time spent sealing up cracks with foam paid off. That is good news for energy efficiency.

ACH50 is commonly divided by 20 to arrive at a value for "natural" ACH (without the blower creating a pressure difference). That means my home naturally changes air over 20 times less than what is considered a "tight" building. This is great for keeping heat in the home, but can lead to poor indoor air quality (IAQ).

While building the home, I took precautions to ensure adequate IAQ such as:

• installing a French drain under the slab to reduce potential for radon gas inside the home
• installing only electric appliances - there are no combustion appliances which would create carbon monoxide
• using low or no VOC materials inside the home

Even so, carbon dioxide (CO₂) will buildup from human activity in the home, and mold can be an issue in moist areas like the bathroom. There are several things we can do to maintain acceptable IAQ given these potential pollutants.

• on sunny days, it is warm enough in the home to open windows
• on days when it is too cold or rainy outside to open windows, we should run the exhaust fan in the bathroom for an extended time period
• we could purchase and install a heat recovery ventilation system to exchange stale indoor air with fresh outside air while retaining most of the heat
• houseplants can help reduce certain indoor pollutants

We definitely notice the home is comfortably warm without using the radiant floor heat. We also notice that the air seems stale when the house has been closed up for many hours. Now we have some test data that explains why. Thanks for reading. Feel free to leave a comment.

Day 144 & 145: Rock wall and moving in

On Thursday and Friday, Trevor worked on construction of a rock wall along the north edge of the entry porch. The wall will facilitate drainage and add a few more square feet to the porch area. Here is a pic of the work in progress.

On Friday the crew helped us move in marking the official end of major construction and almost daily posts. There are years worth of projects ahead, and I will post them as they happen. It has been an incredible design and build experience. It will be a most memorable first Christmas in the peace and warmth of this wonderful passive solar home. We call it "casa del sol" (house of the sun). I wish you all a joyous holiday season. Thanks for reading throughout the year!

Day 142 & 143: Cabinet handles andt tile work complete

On Tuesday, Alan from Live Oak Design installed handles on the cabinets. Here is a pic of the peninsula.

On Tuesday and Wednesday, Joshua completed the floor mosaic and vanity backsplash while I cleaned up in preparation for moving in. Below are pics of the tile work. Thanks for reading. Please feel free to leave a comment.