Future Home: House Zero

The Harvard Center for Green Buildings and Cities will lead the effort to retrofit a pre-1940s house to beyond net zero energy performance. The Center’s headquarters will serve as a test-bed for energy efficiency retrofits.


Our research team intends to demonstrate that through a combination of state-of-the-shelf and state-of-the-art technology, this building can produce more energy than it consumes, serve as a learning center for students, and provide a test bed for new technologies. The aim is that outcomes of processes, systems, materials, etc. can be applied to other homes and buildings.


The United States spends $230 billion annually heating, cooling, and powering its 113.6 million homes.¹ As the world struggles with the consequences of rising energy demand, these buildings offer an abundant source of “nega-watts”, or energy-savings potential.  In fact, according to some estimates residential buildings offer at least 35% of all the energy efficiency potential in the U.S.²  Furthermore, with technological advances the U.S. and others could redouble this already-significant energy savings potential.

Due to the rising cost of energy and the growing awareness of climate change due to harmful emissions, the building industry, in recent years, has taken a great interest in conservation resulting in a very small portion of buildings striving for net-zero energy.  Net-Zero Energy Buildings (NZEBs) are buildings that produce at least as much energy as they consume. NZEBs are typically achieved by designing energy efficient buildings and supplying the remaining energy needs through renewable sources. In programs like the Solar Decathlon and others, researchers have demonstrated the potential for houses to achieve “net-zero” energy consumption and better.  Yet most such high-performing houses were built from scratch.  Prevalent in the U.S. and elsewhere, older homes offer a unique challenge.  Pre-1940’s houses in particular often lack modern energy efficiency features; nevertheless, their embodied resources³ and charming characteristics make them desirable for preservation.  The U.S. alone maintains 14 million pre-1940’s houses and spends $32 billion annually to heat, cool, and power them. Yet despite enormous scalability, academic research into deep energy retrofits has been limited, especially in older houses.

¹Energy Info. Administration, Residential Energy Consumption Survey, 2009 ²McKinsey & Company, Unlocking Energy Efficiency in the U.S. Economy, 2009 ³The sum of all the energy and resources that went into building the home.