In the last post, I talked about cost parity and Passive House.

In this post, I'll take it out of the theoretical world, provide a clear example.

We moved into our Passive Bauernhaus in June 2012, but didn't get our first full month electric bill until July. Since then, the electric bill for our Passive Bauernhaus has averaged 663 kWh/month or $81.04/month. This total includes the typical $25 - $30 service charge.

Since it is an all-electric house, we only pay one bill. There's no propane, natural gas, or firewood. Electricity covers all of our loads:

    Well water (pumping)
    Domestic Hot Water
    Heating / Cooling
    Ventilation
    Lighting
    Appliance Loads
    Plug Loads (computers, TV, alarm clock, coffee maker, etc.)

In the previous year, we lived in a Fishersville area townhouse. The townhouse was built to existing codes, circa 2006. In terms of usable space, it was very similiar to the Passive Bauernhaus---4 bedrooms and 3 1/2 baths. It was a multi-family development, so we were sandwiched between two other units of the same size. It used propane for heating, domestic hot water, and the clothes dryer. And, electricity, of course.

I recently dug into our townhouse financial records to look at our utility bill history. After tallying the numbers, our average monthly townhouse bill came to $243.83 (for a full calendar year). The lowest month came to $122.91; the highest jumped to $429.87.

We haven't lived through a full calendar year in the Passive Bauernhaus, so it may be a little premature to call this one . . . but I can't resist. I say that because we're tracking right in-line with the PHPP energy modeling software.

Here's the bottom line: we're saving > $150 / month.

It's not earth shaking, but it's not too shabby either. It becomes significant when you project this over a typical 30 year mortgage.

And . . . it provides the margin that allows a Passive House to reach cost parity.

Adam Cohen is an architect, Certified Passive House Consultant, and a principal at Structures Design/Build in Roanoke, VA. He has been quite successful at promoting the Passive House standard in both commercial and residential projects. Part of this success is likely a result of Adam's energetic personality, but I'm quite sure it also has to do with hard numbers---and economic sanity. Here are a couple of Adam's mantras:

"Do you want to pay for equity or electrons?"

"We can achieve cost parity in residential projects, and for commercial projects,
Passive House offers a really great return on investment."

Structures Design/Build has the numbers to back up these claims. Some of their Passive House projects include:

Franklin County Public School - Center for Energy Efficient Design (CEED)
Emory and Henry College - Hickory Hall Dormitory
Specht Passive House - Custom Home

If you talk to Adam, you will find he is passionate about the financial viability of Passive House. So what is cost parity? And how is energy efficient construction cost effective? Below I'll provide an example:

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Building A is a 2,000 sq. ft. custom home, built to code. Total cost to build is $250,000. And the monthly utility bills for this house average $225.

Building B is identical, but built to the Passive House standard. Total cost to build is $275,000 (10% or $25,000 in additional capital and labor). The monthly utility bills for this Passive House average $75.

Let's assume that both houses have a conventional 30 year loan. In both examples, the owner provides $50,000 for a downpayment, and the bank charges 4.5% interest.

Building A -  Mortgage Payment - $1,013.37
                    Average Monthly Utility Bill - $225
                    Total Monthly Cost - $1,238.37

Building B - Mortgage Payment - $1,140.04
                    Average Monthly Utility Bill - $75
                    Total Monthly Cost - $1,215.04

So, the Passive House has a higher initial cost, but the total monthly bills are equal to a code built house (actually a little lower). This is cost parity.

 And . . . can you guess which house will be more comfortable?