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8/5/2018 » 8/8/2018
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Energy Smart Design for Home and Office
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BNRG is a small consulting firm working throughout Boulder County, the Front Range, and Summit County providing energy audits, architectural design, and energy consulting services for residential and light commercial buildings. They also install heating upgrades for electric, radiant, and solar heat.


Michael O'Brien, the group's founder, describes a few key components of energy efficiency and green architectural design. These include LED lighting, Blower Doors and IR, Framing and SIPs, plus heating, efficiency, and renewable energy sources. 


The rewards of working in the field of alternative energy and energy efficiency are by themselves inherently rewarding, says O'Brien. He often hears from people how simple the solution was--or possibly just the opposite--as they try to grasp the science of building technology and energy. The real reward for him is working with existing infrastructures beckoning to become healthy, energy efficient buildings. The opportunities are many and often easy and affordable to implement.



LED Lighting 

Ahhh, the low hanging fruit, LED lighting. This is the easiest installation, lowest investment cost, and guaranteed payback you will find. O'Brien is often amazed at how much skepticism there is still out there on LED retrofits, and imagines this is due to "a hangover from the CFL boom and bust."

LED lighting quality has improved immensely and continues to lower cost and increase lighting quality and features. No more buzzing with your dimer switches, or flashing candelabras. Compatible switches, ballast free tubes, and auto sensors are catching up and are compatible with the lower wattage bulbs and fixtures. The typical ROI for LED lighting upgrades can be as low as six months and rarely more than three years for commercial buildings.


Blower Doors and IR

The blower door test combined with an Infrared draft analysis can be your next big efficiency jackpot. Depending on results and the building’s age, the savings gained by sealing and insulating can save 25-30% on heating bills. The ROI will vary based on the condition of the building’s thermal boundary, air sealing, and insulation cost, however average ROI’s in our region are 2-3 years.

The image to the left shows an entry door’s worn out threshold weather-stripping, but a closer look shows air infiltration through the sill plate along the baseboards. Simple closed cell foam backer rod, spray polyurethane foam, and a new threshold is a simple fix that goes a long way. Energy efficiency is a unique and necessary field that incorporates building science, logic, conscious behavior from the building inhabitants, and new building practices.

Fast forward to 2016 building permit submittal, and EEIC code compliance consulting services for homeowners and contractors have become invaluable during the permitting process. These mandatory residential green building programs require a builder or homeowner to include a minimum amount of sustainable building components based on the size of the proposed structure. The Boulder Green Points Program, with City of Boulder Planning department, applies to all new residential construction, additions, and remodels larger than 500 square feet.  Many requirements have been adopted over the years and one most recent is a mandatory blower door test before and after any construction.  The blower door test will determine the air exchange rate (ACH), to see how leaky the building is. A table below is the requirement for Boulder Green Building code.  

Total Conditioned area

HERs Index

Increased Efficiency above 2012 EEIC Standards

Up to 3,000 sf.


5 Percent

3,001 to 5,001 sf.


15 percent

5,001 and up


30 percent


The energy audit of the house will quantify the air infiltration rate and annual energy performance of the building according to generally accepted standards for energy audits approved by the city manager. An energy audit, or an optional HERS index rating will also indicate how efficiently the building is operating and where inefficiencies are occurring. A standard home energy audit includes an energy bill analysis, diagnostic testing on the house, blower door test, draft analysis for building envelope leaks, insulation, heating, cooling, and appliance assessment. Once the audit is completed, a report is delivered to the homeowner listing energy saving opportunities. The homeowner must provide the Home Energy Audit (HEA) Certificate, or HERS index with the building permit application.

Framing and SIPs

Many builders and lumber distributors have turned to improved energy efficient framing methods and advanced SIP designs. A typical new home will have a minimum of R 49 in the roof and above garages and R20 in the exterior walls. The more you insulate, the more green points you can earn for your project. Energy efficient heel truss allows for R49 to the edge of the exterior wall.


Heating, Efficiency and Renewable Energy

Alternative heating sources and energy efficiency have been well supported in Colorado. We do have one of the nation’s strongest renewable portfolio standards (RPSs), which requires investor-owned utilities to source 30 percent of their energy from renewable energy by 2020. A growing number of homeowners in the state are choosing to install systems on their homes with no up-front costs. Boulder NRG has partnered up with Go Green Electric and provides a free solar design and cost estimate for the home owner. The price of photovoltaics has dropped and so have installations as solar has become more popular, but the incentive programs offered by utilities like Xcel Energy have decreased. But Colorado also is the hotbed for a new type of solar array, the community solar garden, through which residents can buy a part of a local solar array and use that to offset their electricity costs.


The design scenarios and energy efficient options are as widespread as the buildings and the people that inhabit them. A different scope of work will be unique to each building. However, the one thing in common with all existing buildings will be room for improvement and the wide range of paths to get there.

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