Net-Zero, Passive, Living Buildings, What Does It All Mean?

With so many energy efficiency building terms and challenges out there, what is what? We laid this out in laymen’s terms, btu/kWh acronym free and are keeping it short and simple…or at least try the best we can.

Sungazing House, Salt Lake City, UT

NET ZERO ENERGY BUILDING (ZEB)

Net Zero Energy Building Basic Idea: A building that is optimally efficient and, over the course of a year, generates energy on site, using clean renewable resources, in a quantity equal to or greater than the total amount of energy consumed on site.  Buildings like this are also called net-zero carbon or carbon neutral buildings due to the fact that the on site production of electricity produced and put back on the grid will be equal or greater than the energy consumed from the grid.

Net Zero Building Benefits:

• Environmental sustainability
• Exemption from fluctuations in local energy prices
• Reduction of or an end to energy bills
• Energy credits given by local power suppliers
• Recouping costs of green material investments
• Increased comfort due to more-uniform interior temperatures
• Reduced total net monthly cost of living (energy costs dramatically reduced)

Net Zero Building Example:

• Project:  The Sungazing House|  Custom Residence |  Salt Lake City, UT
• Designations:  Platinum LEED, Net Zero Energy
• Architect:  Lacroix Design
• Builder:  Tall Pines Construction
• Size & Premier SIPs:  3-Story Home, 3,700 Sq. Ft., 12 1/2″ SIP Walls, additional layer of 4″ EPS on the roof. The SIP walls deliver R45 (versus R13 that conventional construction delivers) and roof at R60.
• Sungazing House Photo Gallery with construction and finished photos
• More info on Jetson Green’s list of most stunning platinum projects, 2010

PASSIVE HOUSE (PassivHaus)

Passive House Basic Idea: Passive takes the Net Zero House to the extreme and using almost no energy to heat or cool the home.  Picture a home so efficient that it doesn’t need a furnace! A Passive House focuses on creating an extremely efficient building envelope (roof, walls, floor) that and reduces (and regularly eliminates) the amount of mechanical equipment needed for HVAC systems (Heating, Cooling, etc.). The Passive envelope takes an extreme approach to the insulation, air sealing, windows, doors, and elimination of thermal-bridging … creating a super efficient building that maintains a regulated temperature with minimal additional heating and cooling.  Passive Houses use about 10% of the heating and cooling energy of homes built to meet today’s energy codes.  In addition to the building envelope, Passive structures are intentionally designed as an integrated system, with site orientation, solar gain, energy generation, ventilation, air quality, humidity, health, comfort—and economy—all taken into account with every product and design decision. 

Passive House Benefits:

• Reduction in energy by 70-95%
• Reduction in on-going maintenance of mechanical equipment
• Healthier structures with a tight envelope, eliminates most pollutants entering home
• Minimal cost increase to build as the money normally allotted to mechanical equipment is redirected to increased insulation, windows, roof and walls
• Passive House in Oregon built with SIPs for the envelope is 2,200 square feet and projected 90% energy use reduction resulting in estimated $192 energy bill.

Passive House Example:

• Project:  The Shift House |  Custom Residence |  Bend, OR
• Designations:  Striving for Passive certification
• Design/Build Firm:  Root Design Build Inc,  Portland,  OR
• Size & Premier SIPs:  2,200 Sq Ft, 8″ SIP walls, 12″ SIP roof, the SIP walls deliver a R-42 and SIP roof delivers R-value of 60.
• Shift House Photo Gallery with construction photos

LIVING BUILDING CHALLENGE (LBC)

Bertschi School Science Wing SIP Roof Install, Living Building Challenge

Living Building Basic Idea: Simply put…the ideal building! Living Buildings must show proven performance of producing energy rather than consuming it. Living Buildings reduce the impact on the environment overall and actually benefit the ecosystems they inhabit. Construction methods can vary from Net Zero to Passive strategies, but must also incorporate proven renewable energy, where the elements of the building (solar or geothermal or wind) provide energy needed to operate the building. The structure is required to be completed and fully operational for one year before being awarded LBC certification (more emphasis on actual energy performance rather than meeting guidelines with projections).

• 6 criteria categories:  Site, Energy, Materials, Water, Indoor Quality, and Beauty & Inspiration
• Buildings that produce energy, water and nutrients rather than consume them
• Buildings that are largely devoid of the toxins and carcinogens that typically foul the air and soil in and around any human development
• Where LEED measures how much you’ve reduced your estimated energy use, LBC tells you not to use any at all
• Where LEED gives credit for using percentages of recycled materials, LBC has a long, long list of toxic materials (materials commonly found in virtually everything we purchase) that you simply can’t have anywhere in your building

The Living Building Challenge is a program initially launched by the Cascadia Green Building Council and has quickly become the most advanced green building rating system in the world.

Living Building Example:

• Project:  Bertschi School Science Wing |  School |  Seattle, WA
• Designations:  Striving for Living Building Certificate
• Designed Pro Bono:  Restorative Design Collective
• Premier SIPs:  SIP Roof  (‘moss mat’ installed on top of SIP roof- 1st to be installed on the West Coast)

References:

• Eco-Structure Magazine:  Great Article featuring CEO of the Cascadia Green Building Council and the International Living Building Institute (written by Katie Weeks)
• International Living Building Institute
• Passive House Alliance
• Passive House Institute US
• Buildings.com “Zero-Energy Buildings Defined”