Net Zero Homes Made By Ichijo USA Surpassed Expectations
Clean Technica, December 9, 2015. Image credit: z-home.org
The first net zero energy townhouse complex in the US was built by Ichijo USA in a collaboration with the Port Blakely community and the City of Issaquah. It met and even surpassed expectations, and some of the highlights are fascinating:
- Over 562.8 kWh was generated above what zHome consumed, and was put back onto the grid between April 2013 and April 2015.
- zHome exceeded net zero energy by 3.5 percent, or almost $54 worth of electricity.
- PV arrays range from 4.8 kW to 7.2 kW and performed 24% better than modeled.
- The goal of reducing water consumption by 70% was achieved. The average zHome per capita daily consumption was 16.07 gallons from the utility and 11.46 gallons of rain water.
What are the typical utility costs for one of your homes?
zHome has a net-zero utility cost on an annual basis. This means that electrically the homes are net-zero, and with the production incentive of power being put back onto the grid, water and sewage costs end up being offset. However, this does depend on the whether or not the homeowner applies revenues towards their utilities. Sun Ridge is a community in Issaquah that is active under construction. We are building the homes with solar standard, which translates to a 30 percent to 50 percent reduction in costs of utility bills. Other communities without the solar standard option have 10 percent to 15 percent savings from energy performance features like increased insulation, efficient appliances, high efficient heating systems, and LED lighting.
What energy efficiency measures are included in each home?
There are a wide range of efficiency measures we employ on our projects depending on the type of home. For zHome we used a geothermal heating system and our insulation was double the required code. The building of zHome was the most rigorous process I’ve ever been through. We used only regional materials, recycled materials where available and all green building industry standards were applied. The development was the first Salmon Safe certified residential project in Washington State and included FSC certified lumber, no PVC and low or zero VOC finishes on all surfaces. Ichijo is now taking all of the energy related performance items and implementing them into current projects. The consumer can really see their return on investment when it comes to items like solar panels and the 420% efficient heating system we used in zHome.
All of the homes we build include what we call our advanced envelope. This includes increased air tightness, at a benchmark three times the current code, increased insulation, 10% above the required code and high performance windows.