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Orange County Great Park, Irvine, California
October 8-18, 2015

Cal Poly: California Polytechnic State University, San Luis Obispo

Team website:

California Polytechnic State University, San Luis Obispo, returned to the U.S. Department of Energy Solar Decathlon in 2015 with a house designed for coastal California. As such, INhouse addresses the majority of its heating, cooling, and lighting needs architecturally.

Its public and private "wings" are serviced by an active "core" that contains mechanical, electrical, plumbing, and monitoring systems. The private wing includes a master bedroom and a flexible library/office/second bedroom. The public wing contains entertainment and dining spaces that open to exterior areas and the views beyond.

Design Philosophy

Interactive. Intuitive. Integrated. This is Cal Poly's interpretation of net-zero. INhouse explores the connection between system and resident with the goal of making operation and management intuitive, energy-affordable, and waste-minimal. INhouse is a manifestation of Cal Poly's core directive: Learn by Doing.



    • Through use of a folding window-wall, the public module blends into a generous outdoor area, doubling the public space.
    • The walls and roof of the public and private modules are made of structural insulated panels (SIPs), which offer higher R-values and faster construction than traditional materials.
    • The elongation of the house along the east-west axis takes advantage of passive solar design principles to harness and control southern solar exposure while minimizing overheating on the east and west sides.
    • INhouse harnesses solar energy through conventional photovoltaic panels, solar thermal water collectors, and bifacial panels.
    • A constructed wetlands system cleans and recycles all the greywater the house produces and directs it to be used for landscape irrigation.


    • A standard air duct contains bio-based phase-change material, a non-food palm oil, that absorbs and releases heat to passively cool or heat the house and reduce the need for the HVAC system.
    • A translucent roof of bifacial solar panels over the patio blends indoor and outdoor space by creating a shady extension of the living space.
    • A central low-power server collects data from built-in temperature, humidity, power generation, and power use sensors and feeds it to a smart home app, which outlines data on the occupant's smartphone or tablet and makes it possible to apply data-mining techniques to reduce energy use. 
    • A simple control application enables the occupant to monitor, manage, and personalize the luminous and thermal environment. 


    Market Strategy

    INhouse is designed for a couple or an individual with a willingness to interact with and adapt to the net-zero philosophy—to learn by doing—in coastal California. Although Cal Poly could have designed a house that operates independent of its residents, it believes a "smart home" is of less value to society than a "smart resident."

    What's Next

    After Solar Decathlon 2015, INhouse returned to the Cal Poly campus, where its performance will be monitored.


    Sandra Stannard

    Neither the United States, nor the Department of Energy, nor the Alliance for Sustainable Energy LLC, nor any of their contractors, subcontractors, or their employees make any warranty, express or implied, or assume any legal liability or responsibility for the accuracy, completeness, or usefulness for any purpose of any technical resources or data attached or otherwise presented here as reference material