The need to increase the energy efficiency of our homes and buildings is imperative. Whether we approach this need from a purely personal economic perspective, or consider the security and resilience of decentralized local renewable energy generation, or desire to protect environmental health: the manifest result is a reduction in energy consumption.
Realizing that a home, once built, will likely undergo major remodelling/ renovations only once every 30 to 50 years - careful thought and planning up front can provide important energy savings for decades.
There are a spectrum of options available for energy-efficient construction:
'Building code' - whether national codes like the International Building/ Residential Code (IBC/ IRC), or the International Energy Conservation Code (IECC), or state codes like the Virginia Uniform Statwide Building Code (USVBC) - represents a basement-floor approach. 'What's the least that can be done to build this today' accurately represents the 'lowest' level of energy performance, building 'to code'.
Changes in the 'lowest acceptable' level performance have been made to national codes, however, improving by each three-year national code cycle. State legislatures modify national code energy requirements, selectively changing, waiving, or diluting statewide scope of national requirements. Even so, progress on energy-efficiency performance is noticeable at the state level. Most in the building industry admit change in energy-efficient requirements is inevitable.
Energy Star for Homes
Promoted by both the US Department of Energy (DOE) and the US Environmental Protection Agency (EPA), Energy Star is not simply a program encouraging use of energy-efficient appliances. Energy Star is applicable to the design and construction of the entire home.
Energy Star requirements have been upgraded through three versions, to maintain the program's relevance and meaning for energy efficiency compared to improving building codes. Version 3 of Energy Star in 2012 aims for a 30% reduction in home energy consumption compared to a 'code built' home.
Promoted by the US Department of Energy (DOE), the program starts with the Energy-Star level of energy efficient performance, and encourages further, significant reductions. 'Net Zero' - a term defined below - is the stated eventual endpoint for energy efficiency under the Builders Challenge program.
Conceived as a 'factor ten' reduction in energy consumption, Passive House aims for energy consumption savings of up to 90% compared to earlier 'code built' buildings. Passive solar design principles are present in Passive House, but the Passive House paradigm is far more comprehensive. The Passive House energy-modelling tool for calculating heat gains, heat losses, and energy consumption, for example, is one of the finest in the world.
A key goal for 'Passive House' is tailoring the building enclosure to its environment. Optimizing the thicknesses of insulation, optimizing window and door performance, orienting building features to accept sunlight inside during the heating season and shade from sunlight during the cooling season, Passive House is perhaps the ultimate metric/ performance certification for heating and cooling energy conservation.
net Zero & net PLUS
In discussing programs and certifications with our clients, we are clear and honest about both the 'pros' and 'cons' of obtaining certifications. Fees associated with certifications and program entries are an obvious 'con'. Designers and builders enjoy programs and certifications, at least in part, because their awards and accolades are paid for by others - their clients. So long as the program / certification is wanted and desired by the owner, in full knowledge of costs and benefits of getting that certificate, that is perfectly fine.
Owners not wanting to pay organizations and their experts for 'blessings', may be interested in pure 'net Zero' or 'net PLUS' energy performance.
Energy Performance Monitoring
In discussing programs and This is appealing for at least three reasons:
- verified performance information, on your building
- independence from arbitrary blessings of others
- knowledge about your energy consumption behaviours, which empowers you to achieve goals you set
This should be viewed as the cherry on top of the sundae, inasmuch . . .