The new Athens County EMS station is now under construction. I was part of the design team and consulted on bringing the building in as a net zero (or very close to) energy building.
To achieve this, we started with a super insulated, airtight, properly oriented, and glazed shell per passive house design. Once you eliminate 70 percent or more of the energy loss through proper shell design, getting to net zero is much easier and far more environmentally forward thinking than most other paths.
The final application of active renewables make the finished product net zero.
The construction is an R26 insulated thermally broken slab on grade (6” sub slab EPS), R38 insulated thermally broken double wall, and an R52 insulated ceiling. The glazing (glass) will be double paned, sized and located primarily south for free winter heat from the sun and shaded in the summer.
The target air tightness is 1.0 ACH50 (to be verified via test). With this design and at 8,200 sq. ft. treated floor area (combined office and garage space) — I estimate the building will use 36,000 KwH per year to heat and cool it. Using rough numbers — that is $360 per month at $0.12 per KwH. All of this is not including plug loads.
The estimated additional cost for the ‘super shell’ is a mere 4% over standard construction. Looking at that number and the saved annual energy costs- I estimate payback in 6-9 years. This building will save Athens taxpayers a lot of money in heating and cooling bills over the useful life of the building. It will be more comfortable for the employees and have superb indoor air quality due to the inside air being constantly ventilated (a must when you build airtight). The addition of the active solar array will cancel out the balance of energy the building will need.
And why again... are we not building all buildings this way? Look for the follow up article once the building is finished and in use.
Jason Morosko is an Athens County resident and a certified passive house consultant.