Harvard HouseZero

The Harvard Center for Green Buildings (CGBC) at the Harvard University Graduate School of Design, in collaboration with Snøhetta and Skanska Technology, are retrofitting CGBC’s headquarters in a pre-1940s timber-framed building to become one of the world’s most ambitious sustainable buildings. As a first-of-its-kind research project, HouseZero demonstrates how to transform a challenging building stock into a prototype for ultra-efficiency, rapidly reducing the level of reliance on energy-intensive technology while simultaneously creating comfortable indoor environments. HouseZero attempts to address the global environmental challenge of climate change by focusing on existing buildings, which account for energy inefficiency and carbon emissions on a vast scale worldwide. Through intelligent design that generates inspiring work spaces and a comfortable indoor climate, HouseZero achieves groundbreaking reductions in energy use and carbon footprint. Once completed, the building will produce more energy over its lifetime than was used to renovate and operate it. This measure considers the building’s total life-cycle, including the embodied energy for construction materials, building operations and equipment plug-loads over a 60-year lifespan. “Before now, this level of efficiency could only be achieved in new construction,” said Ali Malkawi, professor of architectural technology at the Harvard Graduate School of Design, founding director of the Harvard Center for Green Buildings and Cities and the creator of the HouseZero project. “We want to demonstrate what’s possible, show how this can be replicated almost anywhere, and solve one of the world’s biggest energy problems - inefficient existing buildings”. In combination with an open and interdisciplinary creative process, ensuring a holistic and universal concept for the design, HouseZero is based on the following design strategies:
_optimized building envelope in that new and enlarged windows and skylights with high insulation values provide light and ventilation
_100% natural ventilation controlled by a window actuation system, which employs sophisticated algorithm-based software and room sensors to automatically open and close windows to maintain a quality internal environment
_100% daylight autonomy through sculpted window shrouds that protect interior spaces from direct sun during summer months to reduce required cooling, yet allow winter sun into the space to reduce seasonal heat demand
_close to zero delivered energy for heating and cooling by adding mass to a timber-framed building, enhancing its thermal inertia, allowing the building to smoothly buffer swings in local temperature; the minimal heating and cooling systems are driven by a small responsive pump, adapted from ultra-efficient Nordic technology, the power requirements of which are generated on site
_acoustic quality through the treatment of the existing structure, from exposure of the beams to creation of double height spaces; the addition of the facetted stairwell is designed to reduce potential disturbance to the working spaces from human circulation
_functional interior finishes (natural clay plaster, birch wood finishes, ultra-high-slag content concrete and nanoceramics)
_zero energy and carbon emissions
_testing and development of new solutions for a global market, where the long-term goal is to pioneer new energy efficient solutions to be released into the market.