By Jamie Daugaard
What is a net-zero building or zero-energy
building? Generally, these are defined as structures
that create as much energy as they consume.
They are high performance buildings with
the ability to generate their own energy without
depending on external power sources, whether
from propane, wood or power plants. Standard
energy production, in contrast, uses non-renewable
resources such as natural gas and coal.
There are two straightforward steps to creating
a building that doesn’t use or decreases dependence
upon outside energy and non-renewable
resources:
1. The first and most important step to creating
a net-zero building or home is to reduce the
amount of energy the building needs. A goal of
60 percent energy reduction or more can create a
significant impact. In residential buildings, most
of the energy is used for space heating, cooling,
water heating and lighting (45 percent, 9 percent,
18 percent and 6 percent of total consumption,
respectively). These areas have the greatest
and easiest potential for energy reductions.
2. After reducing energy consumption
through design techniques, we devise strategies
to generate the energy needed for the
building. These strategies include alternative
energy sources such as building integrated
photovoltaic systems, wind
turbines, and micro-hydroelectric turbines.
A building can even generate excess energy
to sell back to the energy companies. In addition,
local, state and federal governmental
agencies and power companies offer many
incentives for the installation and purchase
of renewable energy systems.
Living in a home with reduced outside
energy use creates cost-savings, reduced
environmental impacts, and allows for independence
from fossil fuels. After a short
payback period, your house could transform
into an “energy factory” and run for free!
Using interactive energy modeling, we
test many different applications to reduce
energy use. These include:
Reduce heating and cooling loads
• Minimize square footage (less space to condition
and/or light)
• Shade (deciduous) trees – In summer they
decrease need for cooling, and in winter
they let in heat and light from the sun.
• Proper building orientation – passive heating
and cooling from the sun
• Tight building envelope – proper sealant
techniques for windows and doors, insulation
values
• Solar hot water heaters and radiators – Uses
the sun to heat water for household use or for
use in radiant baseboard and in-floor heat
• Thermal mass – Uses materials that hold heat
well like water and concrete to collect heat
during the day and offload the heat at night.
• Alternative heating and cooling methods like
geothermal (uses the stable temperature of
the ground to pre-heat and pre-cool air for
conditioning)
Reduce lighting loads
• High windows, solar tubes, skylights and light
interiors – bring natural light into the core of
building
• Building automation – integrated sensors find
where energy is or isn’t needed and optimizes
where needed (reduces lighting, heating
and cooling loads)
