Blog › Cracking the code on better buildings


Cracking the code on better buildings

Marc Lefkowitz  |  11/16/12 @ 10:00am  |  Posted in Building new, Home renovation

What's so striking about the ratcheting up of building codes in Ohio is not that it took a few more years than average for the Buckeye state to adopt the 2009 standard from the International Energy Conservation Code (IECC).

No, the bigger revelation may be how—at the behest of city council and sustainability advocates—Cleveland Mayor Frank Jackson willed his city's tax abatement beneficiaries to accept green building standards. As evermore stringent building codes come to cities, it continues to be one of Jackson's most important policy moves (in terms of dealing with climate change).

Going deep<br />An old home in Cleveland undergoes a Deep Energy Retrofit That's a wrap<br />The CMNH SmartHome's permanent foundation includes Insulated Concrete Forms

Why? As GreenCityBlueLake wrote at the time, a city with a tax abatement policy places a very valuable card in a mayor's deck.

In summer 2012, Ohio joined 30 states in adopting the 2009 IECC code to set a bar for energy performance in buildings. Three states have already embraced the more far reaching 2012 IECC code.

Energy codes may be a case of policy trumping preference. As anyone familier with 'green building' knows, it can be a squishy term. Code updates are the sharp end of the stick in reforming a fairly lackluster building industry in the U.S. for energy performance. Beyond the numbers for energy efficiency, which are impressive, the latest codes should prod sub-contractors in a way that no stack of glossy articles on green building can. Building advocates note, builders will have to look at the whole house in a new way, and adopt higher quality construction standards in order to hit new, stringent air tightness and energy targets.

At a session on the impact of new codes, Northeast Ohio builders, developers and architects affirmed that codes and policy like Mayor Jackson's are indeed driving change. There was a grudging agreement in the room from building industry folks that enough value can be wrung from Cleveland's tax abatements that they will start to rethink their whole approach to construction now in order to not leave thousands of dollars on the table.

Tying Cleveland's residential tax abatements to standards like Enterprise Green Communities means home construction in Cleveland should reach an even higher bar than the state's 'new' 2009 standard.

Ohio's new standard is equal to EnergyStar 2.0—so, new buildings will meet a minimum 15% upgrade on energy performance. That incremental upgrade, however, is not what's triggering the shift for builders. Those who want the Cleveland tax abatement dollars agree to a higher standard. They have a range of options that top off at EnergyStar v3.0. USEPA's voluntary building standard is a game changer, says Environmental Health Watch Affordable Green Home resident contractor Matt Berges.

"It changes the whole process because there's a thousand details that have to be coordinated," Berges says of EnergyStar 3.0. "There's more emphasis on best practice and building science."

In a nutshell, all of the tradesmen involved in the building of a house will want to coordinate as never seen before, and adopt new techniques because, at the end, their work is being tested and verified, Berges says. For example, bathtubs, fireplaces and windows produce too much air leakage when dropped in to a rough framed wall. They'll have to be completely built out with a super-insulated six-sided box to avoid what is known in the building science industry as thermal bridging, which is essentially the loss of energy through walls.

Berges, who doubles duty as a private contractor and full time staffer for nonprofit group Environmental Health Watch (EHW), shared lessons from the rapid prototype of near zero energy homes that he already built and tested against the cold climate of Cleveland.

With federal Energy Efficiency Block Grant funding, EHW renovated a half-dozen old homes in Cleveland, adhering to a principle they call Deep Energy Retrofits (DERs). Berges also learned from the PNC SmartHome and was the contractor on a second passive house built in 2012, in Cleveland Heights. He's interested in downscaling passive building methods to smaller, more modestly budgeted projects.

He walked the room through his top priorities for meeting the new codes:

He starts with a layer cake of insulation below the slab, the concrete pad on which a house sits. While most homes have concrete poured on top of gravel, Berges' team discovered that adding extra layers of insulation below, and Insulated Concrete Forms in the walls with everything wrapped in rigid foam board and plastic sheets creates a strong air and moisture barrier where your home touches dirt. It's like wearing a pair of rubber sole insulated boots to a Browns game.

Next up: Where the foundation meets the basement walls, Berges pays special attention to doubling up insulation and air sealing a usually windy gap called the rim joist.

If they pay some attention and properly install relatively inexpensive insulation material at every stage of building, any average builder can stop a lot of air 'infiltration' here, says Berges. He adds details like firring strips so that when drywall or flooring is nailed in, it doesn't penetrate air barriers.

The sidewalls are like the inside of a Thermos—with two thick insulated wall panels and an air barrier between them. They blow in Fiberglas insulation between the studs, cap it with rigid foam insulated boards and wrap it in plastic sheeting before the drywall goes up. The new code and EnergyStar 3.0 both call for an R value of 20 in the walls (current code is R-13).

On windows and doors, Berges acknowledges the U.S. doesn't make the world's best like the triple pane, shut-like-a-vault at three points in the SmartHome. So, use the best you can find and afford. The same goes for appliances and lights (EnergyStar 3.0 still doesn't require LEDs) so look for EnergyStar rated and install CFLs.

But perhaps the greatest change is happening in the attic. Recently, builders have confirmed that packing tons of insulation in to a roof may be better than the condensation problem of warm air rising from the second floor of a house colliding with cool unconditioned air in the attic.

Essentially, they recomend building a 'hot' or heavily insulated roof since it may be the single best way to slow hot air escaping. With less hot and cold colliding, it will cut down on moisture. For new construction it will still be a challenge but not impossible to design roofs that meet EnergyStar 3.0's eye-popping R-38 for the whole attic.

"There's a lot of little things we can do better," Berges assures. "With retrofits, I would start at the top, upgrading attic insulation and air sealing and then insulate the basement rim joist.

"On new construction, we need to simplify things in design because (insulation and ERVs) cost money. The upgrade payback is in the efficiency.

Start with an energy modeller. You can plug your specs in and see an estimate of your energy consumption, he adds.

When EnergyStar 2.0—again, that's equal to Ohio's new code —first came out there was a lot of grumbling, too.

But, getting to EnergyStar is not hard, says Berges, a younger and perhaps more open-minded contractor than some crusty veterans of his trade.

Berges has hands-on experience with the cutting edge of green building. He recognizes that not every new idea has a reasonable payback. That's why, when he slips a provocative question to the group, you sit up and take note.

"Why would you want to put a house on the market with 2009 standards when you know the 2012 code is coming?"

The voluntary EnergyStar 3.0 is a good preparation for the IECC 2012 code, Berges said, because it requires a blower door test to prove that it was "built tight and ventilated right" (yes, a whole house mechanical ventilation system is also a requirement of the IECC 2012 code).

Ohio's new code represents incremental improvement. But the 2012 codes (which Berges predicts will be adopted in a couple of years in Ohio) are the real game changer. They call for a very strong green building standard of 4 ACH (Air Changes per Hour) @ 50 pascals (that's the negative pressure produced by a blower door test. To put it in to context, Berges says he's built EnergyStar 2.0 homes that are scoring 7 ACH @ 50 Pa. One of the more recent deep energy retrofits his crew built scored a very impresssive 0.6 ACH, achieving the passive house standard). With blower door tests and mechanical systems required, the emphasis shifts to thinking of the whole house as a system.

Does the new code signal a sea change for energy use in homes?

In many ways, yes, but the systems are in place to meet the challenge.

It's harder to install a system that just ventilates stale air versus a Energy Recovery Ventilator which can reuse the heat energy from stale air, Berges says. With a air-source heat pumps like the 'mini-splits' used in Cleveland's first two passive homes (now available at big box stores), the heat that normally gets vented powers a 98% efficient heater/cooler.

Berges also recommends to builders that they rough in a waste plumb line on new construction, to anticipate codes that will lead to greywater capture systems being commonplace. He notes that 2012 codes are already looking at water use.

That line of thinking may not come easily to tradesmen in Northeast Ohio. To help ease their passage, market preference for green building may indeed play a growing role. If for no other reason than to assure builders that the hard work of adopting to new codes is worth it for occupants who get to reap the benefits like lower energy bills, more comfort, and greater durability.

  • Comments
  • Print

Leave a comment »

Filter by RSS

Social media feed

10 best ecological restoration

10 best ecological restoration >

Cities are healthier as a whole when nature is invited in.

10 ways to stay cool and save

10 ways to stay cool and save >

See these tips to beat the heat and save money.

The best bike trails

The best bike trails >

Find out where are the most interesting bike rides in Northeast Ohio