Green building (also known as green construction or sustainable building) refers to both a structure and the using of processes that are environmentally responsible and resource-efficient throughout a building’s life-cycle: from siting to design, construction, operation, maintenance, renovation, and demolition. In other words, green building design involves finding the balance between home building and the sustainable environment. This requires close cooperation of the design team, the architects, the engineers, and the client at all project stages. The Green Building practice expands and compliments the classical building design concerns of economy, utility, durability, and comfort.

Deep Energy Retrofit (DER)

Buildings consume nearly three quarters of the electricity produced in the United States.   A Deep Energy Retrofit (DER) can reduce an existing home’s energy appetite by fifty percent or more.

DER is a comprehensive renovation that affects the entire building envelope, from roof to basement.  Features of DER typically include:

  • Superinsulation and fastidious air sealing
  • High performance windows
  • Advanced building systems and controls
  • Stringent moisture control

There are many ways to approach a DER depending on the age and structure of the house.  KHC works with architects and engineers to assess the most appropriate techniques for each home.

For information about DER as pdfs: 


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Like a high-performance car, Passivhaus relies on precision engineering.  Since these homes are custom designed to meet our clients’ needs, we work closely with teams of architects and engineers to precisely model the technical details necessary to create the sturdiest, most energy wise, and livable homes that will stand the test of time.

Wood plus moisture equals rot, the main reason for structural decay.  To keep our houses solid and dry we plan for both bulk water control, such as gutter design, and moisture that forms within the walls.  Even when the air feels dry, water from condensation pools inside wall cavities.  Internal condensation is inevitable so we do extensive computer modeling and detailing to ensure that the walls will dry


It is common for houses to have hot and cold spots but our Passivhaus homes are designed so that every square foot of the house is within a few degrees of optimal temperature.  No need to worry about sitting near the window when the wind is blowing hard and the outside temperature is twenty degrees.  Every square foot is of living space is usable and feels very pleasant.

Net Zero

net zero building, is a building with zero net energy consumption, meaning the total amount of energy used by the building on an annual basis is roughly equal to the amount of renewable energy created on the site. These buildings consequently contribute less overall greenhouse gas to the atmosphere than similar non-ZNE buildings. They do at times consume non-renewable energy and produce greenhouse gases, but at other times reduce energy consumption and greenhouse gas production elsewhere by the same amount.

Most zero net energy buildings get half or more of their energy from the grid, and return the same amount at other times. Buildings that produce a surplus of energy over the year may be called “energy-plus buildings” and buildings that consume slightly more energy than they produce are called “near-zero energy buildings” or “ultra-low energy houses“.

Traditional buildings consume 40% of the total fossil fuel energy in the US and European Union and are significant contributors of greenhouse gases. The zero net energy consumption principle is viewed as a means to reduce carbon emissions and reduce dependence on fossil fuels and although zero-energy buildings remain uncommon even in developed countries, they are gaining importance and popularity.


Most zero-energy buildings use the electrical grid for energy storage but some are independent of the grid. Energy is usually harvested on-site through energy producing technologies like solar and wind, while reducing the overall use of energy with highly efficient HVAC and lighting technologies. The zero-energy goal is becoming more practical as the costs of alternative energy technologies decrease and the costs of traditional fossil fuels increase.

The development of modern zero-energy buildings became possible not only through the progress made in new energy and construction technologies and techniques, but it has also been significantly improved by academic research, which collects precise energy performance data on traditional and experimental buildings and provides performance parameters for advanced computer models to predict the efficacy of engineering designs.