Lets hope that future projects aren’t hampered by political Eco-one-upmanship.

Kudos to the city of issaquah for having the infinite wisdom to approve and administer approval paperwork for the project. Kudos to PSE, WAZU energy, King Co. and built green for endorsing themselves.

Kudos to Vandervort, Howland and their team of uncredited professional engineers and consultants for actually doing the work.

“Something for nothing” is right.

Lots of great thoughts here, I appreciate them all. So maybe I’ll just roll through them.

Dan – yes, PV is expensive. I guess I would argue that the tax incentives ARE real and in some way a reflection of externalities, albeit not going far enough and in a haphazard way. I also believe there is an argument to be made that even though PVs are expensive now, as the market for them ramps up, they will get cheaper. That’s the logic I took when I paid custom prices several years ago for a tankless hot water heater – to some degree I was subsidizing the future market acceptance – and I note now they are indeed a lot cheaper to install.

Regarding achieving net zero – ultimately, achieving this goal will indeed be in the residents’ hands. Once you cut all the fat out of homes’ energy use, the plug loads dominate, and there is a very wide range of what individuals do on this front. The design team had many, many hours of conversations about what were reasonable assumptions for our typical residents. We folded those into the energy model. We will be sharing those with the residents as they move in so they understand what assumptions we made for them (in the case of TV – a 28″ LCD operating two hours a day).

Regarding the zero energy label, I agree, wholeheartedly, it is far too broadly used. At a minimum, you are running a detailed energy model that converts all energy expected to be used into a common standard measure and demonstrates you will be completely offsetting that energy by on site production. In many parts of the country (not here) it is de rigeur to say your project is “zero energy” simply because you are participating in the DOE zero energy by 2030 program – to me, false advertising in the worst sense.

In regards to BedZED, it is indeed having a hard time getting to zero (they are very close), but I don’t believe that project ever had a ZE goal. ? Certainly, other projects in Germany are achieving the ZE goal, which gives me some confidence with zHome.

Sabina – I really appreciated your comments. We haven’t looked in detail at acoustic transmittance – obviously, these will be quiet homes. But I suspect most of the sounds you’re talking about are coming through windows rather than walls in a typical new home. And we’re using double, rather than triple paned windows, so the noise transmittance will be the same as a new home, at least through the windows.

Joe – the Shireys deserve a lot of credit for pursuing their very green project – they truly are green building pioneers who have been an inspiration for me and many others. It sounds like they are introducing more rigor into their pursuit of zero energy. I should add that zHome will be using SIPs for roofs (this is not stated on our website at this time). I should add that other differences are that zHome is an attached, market rate, production project (ie, uber green for the masses), and also as I stated above has performed a detailed, thorough energy model to demonstrate achievement of true zero net energy usage (again, assuming green oriented occupants). But at the end of the day, I’m just glad to see more advanced, ultra sustainable building going on – it’s time to quit messing around and change how we’re doing things.

We will be adding a ton of technical details to our website (www.z-home.org) in the coming months so stay tuned there for more info (especially our Dig Deeper section and blog).

The biggest difference between the Issaquah net-zero energy homes and the Zero Energy Idea House? Instead of using standard double-stud walls, the Zero Energy Idea House is using Structural Insulated Panels (SIPs), one of the most environmentally responsible building systems available. A SIP building envelope provides high levels of insulation and is extremely airtight, meaning the amount of energy used to heat and cool a home can be cut by up to 50 percent.

(Disclosure: The builders of the Zero Energy Idea House, Donna and Riley Shirey, are my clients through their business, Shirey Contracting.)

Regarding you second point: I wasn’t suggesting that introducing natural ventilation to residential buildings would save a lot of energy in Seattle: as you write, already very few people use AC here. I’m suggesting that natural ventilation (and thus exposure to outside sounds) will be a feature of net zero houses generally, including in climates where AC is now the routine solution.

As for those few authentically warm summer days in Seattle, would it truly be in lieu of operating an air-conditioner that the windows would be open? How many low-rise dwellings in Seattle actually have air-con?

Net-Zero is a concept one can only applaud. Glad it has at last arrived in Seattle. But how will the occupants of a low-rise dwelling fare, psychologically, living behind 10″ of insulation and obliged to keep the windows closed throughout most of the year?

Commonly, the joy of low-rise living derives in significant measure from the sonic backdrop one perceives while indoors, the sense of being protected from one’s physical environment while remaining connected to it. We love to hear the sound of birds, of rain, of wind in the trees, of the postman slipping letters into the mailbox or the of the spouse coming up the driveway.

Much of this sonic panorama lies in a frequency range silenced by thick insulation and airtight windows. The background sounds that remain will be primarily those generated indoors, by electrical equipment. The acoustical experience of living inside a Net-Zero house may prove akin to that of living inside an airport during nighttime shutdown.