Thursday, January 19, 2017

Energy Codes Continue to Prove Challenging for Modular Factories and Builders

This was sent to me by Rick Terry, a HERS Rater with vast experience working with the modular home industry.


Here he talks about new Energy requirements for MA but other states like NJ will also see these beginning in 2017. I wish I could say enjoy the article, but…...

Massachusetts Energy Codes and Common Issues Challenging Compliance at Final Testing

an article by Rick Terry, HERS Rater

The MA Energy Codes continue to be another example of “open to interpretation & enforcement” as the transition from IECC2009/IECC2012/MA Stretch Energy (1st ed.) moves to IECC2015/MA Stretch Energy (2nd ed.)!

Statements have been all over the spectrum on what the current situation is and what the future will require in regard to HERS Rater involvement and application. I as a Rater am continuing to search for “solid” answers so I can both serve you and your clients better but also to determine how I need to adjust my business accordingly.

I don’t have those answers yet but I feel like I’m getting closer. Please see the following link for what appears to be a decent resource for what the code changes will mean to us  including links to the actual regulations, up to date locator maps for Stretch Code communities and the ENERGY STAR® Version 3.1 (Rev.8) alternative.

Based on my recent experience with the requirements of the IECC2012 & IECC2015 codes, especially with regard to building envelope leakage, duct leakage, and mechanical ventilation, I STRONGLY urge you to consider your current levels of air sealing, thermal insulation materials and values, and completion of your mechanical bath fans and range hoods. The majority (I’d say roughly 80%) of houses I have tested under the new code requirements have failed the air leakage requirements during the blower door test. Air sealing of the building envelope in the plant and on site is critical to meeting the minimum requirement of 3AirChangesperHour at -50 pascals; a 40% reduction from the 5ACH50 that the IECC2009 required.

The majority of issues are site related, post set, which is always a great challenge due to the number of independent contractors trying to get their respective jobs done and not having any responsibility for the air sealing issues. Here are some of the most common issues challenging the tightening of the envelope:

Marriage walls sealed with expanding foam on all horizontal and vertical exterior seams (prior to covering with sheathing); center beams in attics and basements; interior cross over areas at interior doors and archways. The foam gaskets used in the marriage wall by plant and set crews are a start but DO NOT provide adequate air sealing needed. Additional air sealing, preferably an expanding foam product is required to insure meeting envelope leakage code requirements.

Air sealing with expanding foam and/or caulk of plumbing and electrical penetrations made by contractors on site; sealing radon vents, conduits, and HVAC chases on top and bottom.

Sealing off under tub/shower drain cut outs once plumbing is complete. This are major sources of air leakage in the building envelope as well as between floors which creates more depressurization that pulls air in between floors/units and coming out through unsealed areas of the interior walls like outlets, switches, others. This also occurs where sink drains go into walls and/or through the floors. Also, caulking or foaming between drywall and floor on any walls adjacent to unconditioned space /exterior behind or under tub/showers PRIOR to installing. Just because it is out of site does not mean that these areas do not need to be air sealed when on outside walls. (Same for HVAC chases and fireplaces)

Fireplace box outs need to be completely air sealed at all seams and joints especially top at ceiling to vertical wall and floor to wall; the through the wall vent needs to be addressed as well. The fireplaces are causing a lot of leakage issues; I know there are concerns about both insulating around and air sealing the vent and collar. I spoke with some manufacturers’ reps about using mineral wool for insulation around the flue and the hi-temp red caulking to air seal around the collar and any other seams that can cause leakage. They verbally confirmed with their “higher-ups” that this would be acceptable and not violate any warranties or compliance. I haven’t yet received the confirmation in writing but will definitely get it distributed as soon as I do!

Appliance installs cause additional unsealed penetrations; prior to final install, air seal drains, supplies and electrical wires that were run post set. In addition, even the water lines for ice makers need to be air sealed at the floor or wall.

Condensate drains for HVAC, emergency relief drains on WHW, etc. need to be extended into drains through appropriate grommet to air seal or equivalent. These drains are notorious connections between conditioned and unconditioned spaces.

Weather-stripping doors to basements and attics plus making sure the sweeps or sills seal the gap at the bottom of the door is very important. I’ve also caulked between the casing and drywall on the conditioned side of these doors which is a common source of leakage.

Electric service panels in conditioned spaces on exterior walls are another challenge to air seal. The manufacturers are doing a lot better job in the plants insulating and air sealing around these. Again, once the work on site is started, the leakage becomes more of a challenge as lines are run and service installed. These conduits need to be sealed with appropriate materials prior to energizing the service.

I recommend that builders air seal between the sill plate and top of foundation; better yet, use a two part or single part foam product to spray closed cell foam product to spray the inside of your band joist cavities in a continuous coverage pattern over top of the sill plate and onto the top of  the foundation wall. This provides both an excellent thermal barrier as well as air sealing. Several builders also spray foam between the band joist where it makes contact with the sill plate to the top of the foundation wall on the exterior which is an excellent technique as well.

Double check the air sealing of light boxes, smoke detector boxes, outlets, switches, recessed lights, mechanical bath fans and any other penetrations between conditioned and unconditioned space. There is still a measurable mount of leakage in these areas that can make or break meeting the code numbers.

Sealing between HVAC registers and mounting surface (drywall ceiling, hardwood & tile flooring, etc. ) This is typically a site issue but it causes major challenges for both envelope leakage and duct leakage if not done or done well enough. This can be a major area of leakage if not addressed.

Toe kick HVAC registers in kitchens and/or baths need to be properly constructed and air sealed to prevent both duct and envelope leakage. A typical “old School” installation can be a boot mounted on the underside of the floor under a cabinet, a hole cut through the floor into the empty cavity created by the cabinet frame, and then a register cut in the toe kick to let the conditioned air pass through that is emptying into the cavity under the cabinet. This is no longer acceptable and will cause the final testing to fail for duct leakage and increase envelope leakage most of the time as well. IF the HVAC contractor demands that they utilize a toe kick register, they MUST construct and install it correctly.

The register, boot and duct needs to be a continuous unit from the toe kick to the supply trunk and any penetrations between conditioned & unconditioned space fully air sealed to prevent envelope and/or duct leakage.

This industry has made terrific strides to meet the challenges of the various energy programs and codes over the last 13 years that I’ve been directly involved with them. This latest code may be the biggest challenge yet, especially for smaller residential units and multifamily projects as less conditioned space of smaller living spaces is hardest to find areas of opportunity to get to the numbers; larger houses are easier to attain lower numbers with. This issue needs to continue to be taken seriously by manufacturers and especially their builders/clients as it is a difficult task to accomplish without vigilant diligence.

Please feel free to contact me with any questions. I will update you if anything is worthy to report.

Rick Terry
Frederick “Rick” G. Terry III, C.E.M.
Eco-Haven Building Systems
764 Dry Run Road, Beech Creek, PA 16822
570-660-1122 p

RESNET HERS Rater/QAD #2561852


Rick Terry said...

My original intention was to let my clients know the current challenges of the new energy codes, but after speaking to Gary about recent testing results,I agreed it could help others as well if they were interested.

I want to make this very clear...I can not say enough about the way that most of our industry manufacturers and builders, especially the ones I am fortunate to work with, have been achieving great results at final verification and testing. It has become the norm to see most houses earn a HERS Index of under 60 consistently with several builders averaging HERS Indexes of 38 to 48. For reference purposes, like a golf score the lower the better where 100=The same home built to typical code standards and 0 = a zero energy home, I.e. using renewable energy to offset the energy use by its occupants.

So, overall, modular homes and it's industry stakeholders have been and are going in the right direction for its clients, achieving excellent results and building energy efficient, healthier, more durable houses.

Builder Bob said...

I know Rick and the amazing work he has and is doing for the modular home industry. If he thinks that meeting all the requirements is getting tougher and more complicated, then I think its time to begin fighting back against these regulations. Where and how to start are always the questions.

Tom Hardiman said...

Thanks for the info Rick!

Builder Bob, A couple of ways to look at this: Energy requirements (at least in the short term) are going to get more challenging to meet for every home builder. I think this gives modular home builders a big advantage over site builders who simply are not going to be able to meet some of these requirements. California for example has mandated that all new homes be net zero energy by 2020!

But to your point about fighting back against regulations, I couldn't agree more! While elected officials change, those a little further down the organization chart that oversee the agencies regulating our industry are still heavily bureaucratic.

MHBA has adopted the mantra of "no new regs" as our starting point for any conversations with state administrators. You are not going to add regs to modular home builders unless those regs apply evenly across the board.

And we have our hands FULL in 2017. See Gary's related story about what is on MHBA's agenda this year - and if you hear about a new regulation - send it to me and we will address it.

Ken Semler said...

This is one area that I feel the modular construction industry can really stand out. In California, current requirements for a code compliant house means it will be Net-Zero by 2020. While our knee jerk reaction to hearing about more regulations is to push back I believe we should really think about this as an opportunity.

What building system is better suited than any other to take advantage of this? As an industry, if we collectively attack this, we will be the only way to effectively meet building code and provide a Net-Zero home in a systematic and automated way in the residential building industry. Steve Lefler has already done it. Harris Woodward is doing great things with High Performance modular construction in Maryland. We are already on the path!

Now think through the implications. As a modular home builder you are providing homes that have no energy bill. What could that save a home owner in a current "used" home? $150 - 800/mo? When you build a new home using modular construction now you don't have that bill any longer! You can either take that savings and put it into a nicer home with amenities you really want or pocket the savings. If you are an appraiser, how much more is a home worth that has no electric/energy bill? $20,000 more, $50,000 more, even $100,000 more. Think about how Net-Zero modular homes could revolutionize the building industry and put it head and shoulders above site built construction. There would be NO competition!

I would submit that there is no other more effective way to meet this upcoming California code than with modular construction. Instead of fighting it and buying time for competing construction methods to catch up, as an industry let's embrace it and be there in 2020. In 1961 it was impossible for a man to walk on the moon. Kennedy set the goal of doing it by the end of the decade and with much effort, in 1969 it happened. I am challenging the industry to standardize on Net-Zero modular home construction by 2020!

Steve L said...

I live in California. My personal modular has been featured for Net Zero compliance.

Rick has defined the devil in the details. Site built can build to the code changes however today 93% fail in CA. by Hers raters. The cost to correct mistakes on site makes the houses extremely expensive to purchase and to make a passing grade.

Harris - Finish Werks said...

What Rick has done here is demonstrate Rule Number One for builders (and manufacturers) new to green/high performance building: BEFRIEND A HERS RATER.

The constant mantra from the unacquainted is, “green is too hard; costs too much; customers don’t ask for it”. Often what the builder is really saying, is, “I’m scared of change”. You don’t have to be. The easiest way to jump headlong into green is to find a great HERS Rater, and let him/her help design the modular home, advise on cost effective HVAC and water heating systems, and model the home in REMRate or some other software… that builders need know nothing about!

The wheel has already been invented, fellow builders. No need to do it again. You just need to get on a good glidepath and land on better building, and greater profits. American buyers are waiting for us.