A newly-completed home, designed by Holst Architecture aims to attain certification from by three distinct, high-performance building standards. The Karuna House, which sits just outside of Portland, Oregon, was built by Hammer and Hand, and is designed to meet passive house standards, while also meeting requirements for both Minergie and LEED Platinum certification. Beautiful, modern aesthetics are not sacrificed in Holst's pursuit of triple certification; the clean lines, simple material palette, and subtle response to program and site make for a shining project from Holst.
The spectacular home will serve as a case study to examine the overlap and divergences between the different certifications. The findings are published in an insightful analysis on Hammer and Hand’s website.
The lessons about building performance were beneficial for all parties involved in the process. The educational outreach within the building community has been another success of the project. The company recorded each phase of construction on their website, which has become a tool and resource for professionals in related fields. As for their own growth, Hammer and Hand stated that “Everything about how we build exterior walls has been affected by the learning process that started at Karuna.”
Integrated design and experienced energy consultation from Intep and local company, Green Hammer, aided the process. Every aspect of this home contributes to high energy performance. It starts, quite literally, with a foundation−a super insulated foundation made with 30% fly ash (to reduce the building’s carbon footprint) and local aggregate. The envelope has been meticulously detailed to create a breathable, yet water and airtight enclosure. Fenestration, which is the most likely source of leaks in a high performance building, had to be carefully detailed as well; triple-glazed windows, liquid applied flashing, along with other techniques mitigate the vulnerable spots in the envelope. An efficient HVAC system was used, although the heating and cooling loads were minimal because of the passive design strategies employed by the architect. Oh yeah, and there is also on site energy generation which will, hopefully, bring the home down to net-zero.
The designers believe that this home will consume 90% less energy than a standard home built to code. The sense of pride that has come with this project is both apparent and admirable; the builders said that this house “presented an opportunity to learn, progress, and become better tradespeople.”
Photos by Jeremy Bittermann