Energy
Benchmarking
Be sure to know your building's energy benchmark. This number will help you understand the range of energy use to expect and help to set a realistic energy reduction target.
Benchmarks are from CBECS 2012, and measured in kBtu/sf/yr used on site
For mixed use buildings - Calculate a weighted average by square footage
For Source EUI - US National Median Table.pdf
For a more detailed benchmark - Use Target Finder
Energy Conservation
Conservation v. Efficiency
“Conserving energy” and “increasing efficiency” are often used interchangeably, but are very different concepts that utilize very different strategies. Efficiency is about minimizing the waste a given system. Examples include swapping out fluorescent bulbs for LEDs or driving to work in a hybrid. Conserving energy is about using less energy overall, often by thinking beyond the boundaries a given system. Examples of conservation would be turning off the lights (regardless of the type of bulbs) or taking the bus. Both conservation and efficiency are important pursuits, but conservation strategies should take priority since they will actually decrease global energy consumption and carbon emissions.
Strategies for Conservation
Smaller buildings
less space per person
Less time that systems are “on”
Fewer energy using systems / appliances
Passive strategies that replace mechanical systems
Fine tuned schedules
Occupant feedback and engagement
Strategies for Efficiency
Improved lighting systems
Improved mechanical systems
Passive strategies that reduce reliance on mechanical systems
Fine tuned equipment
Strategies for Human Health and Happiness (that also happen to conserve energy)
All of these strategies will contribute to energy conservation, but energy will not be their most significant impact.
Daylight - To create an enjoyable space and to benefit occupant health, happiness, and productivity
Limited WWR - To prevent glare, maintain thermal symmetry, and decrease first costs of the envelope and mechanical system
Create thermal breaks - To prevent condensation and mold growth, and increase the durability of the envelope
Continuous insulation- Increase the lifespan of a building
Shading and overhangs - To prevent glare and increase building life span.
Strategies for Designing Low Energy Buildings
All "low energy buildings" are sustainable, but not all "sustainable" buildings are low energy. "Low Energy Buildings" are a subset of sustainable buildings with a goal of minimizing energy consumption. Below are rules of thumb for designing low energy buildings.
Residential Projects - Focus on simplicity
Decrease conditioned square footage
Eliminate unnecessary / redundant / extravagant systems
Lighting / AV control systems
Pools
Landscape ponds / fountains
Redundant HVAC systems
Redundant appliances
Hotwater circulation systems
Ducts
Encourage a sustainable lifestyle
Use of outdoor spaces, outdoor cooking, gardening, etc.
Encourage feedback and engagement
Commercial Projects - Focus on intelligence
Integrate lighting and HVAC with easy to use controls
Ensure that a building manager understand the systems and want to optimize performance
Create lighting and HVAC zones than can be scheduled independently and easily adjusted
Use vacancy and daylight sensors in all spaces.
Minimize energy during "off hours", including low energy security systems
Allow occupants to control their environment
Keep data storage offsite