Author: Brett Little

This year, we have our top 5 most viewed on-demand CEU educational webinars and our top 5 most live-attended webinars.

And the top, the #1 spot… drum roll……..

These top educational sessions featured one common theme: dealing with moisture and humidity in homes.

This is very promising because of all the efforts, funding, and resources into decarbonization, energy reduction, and even ventilation. If we don’t build our buildings to be durable and don’t address moisture issues on our existing housing stock, we might end up with net-zero homes with great ventilation systems that are rotting and falling apart. So it is wonderful to see the interest from our live and on-demand audience in addressing this issue.

Our most viewed on-demand session this year was Vapor Control Barriers: Do We Really Need Them?

The survey results from attendees highlighted that participants gained a deeper understanding of insulation and moisture management, noting the importance of using appropriate insulation and vapor barriers tailored to specific climate zones. They learned about the differences between vapor barriers and vapor control layers, the functionality of smart vapor barriers, and the need for multiple air barriers within a wall assembly. However, several questions remain regarding the implementation and effectiveness of open vapor systems, the interactions between various barriers, and the nuances of moisture transmission in different building scenarios. Participants expressed a desire for clarity on how to effectively utilize permeable barriers and sought further information on innovative products and approaches suitable for their specific renovation and construction projects.

Our most well-attended live session this year was Tools to estimate moisture and humidity risk.

Continuing education is available for both of these as well

GHI needs continued support to keep this session going into 2025 and beyond. Please help us reach our goal of 400 members and get instant access to all our live webinars, with no registration and free on-demand CEUS plus more benefits. Learn more and register here.

In addition, our year-end fundraiser is underway, and we need your help to reach our fundraising goal and keep these sessions going. Give now!

What do you think might be most popular in 2025? What are you looking forward to?

This year, we have our top 5 most viewed on-demand CEU educational webinars and our top 5 most live-attended webinars.

#2 featured two top trends we saw this year: heating and cooling with heat pumps and the interest in solar power applications in homes. The on-demand trending course was our All About Ducted Mini Splits v1 session and our 2nd most attended live course, Solar Shingles: The best re-roofing & new roofing option for a home.

Mike Schaefer, a previous Senior Manager of performance Construction at Mitsubishi, joined us to discuss ducted mini splits.

Participants in the survey gained valuable insights into various aspects of mini-split systems, including the ability to install them within recessed truss frames, the performance of outdoor units in cold temperatures, and the importance of covering outdoor units for maintenance. Many were surprised by the diverse options for indoor units, such as low and medium static pressure models, and learned about modifying truss designs to accommodate ductwork within thermal envelopes. There was a strong emphasis on best practices for installation and maintenance, as well as the effectiveness of different systems in both retrofits and new constructions. However, several questions remain, particularly regarding the intricacies of ducting options, the specifics of mini-split designations, and how to optimize system performance in varying climate conditions. Overall, while the information provided was beneficial, participants expressed a desire for further clarification on certain technical details related to installation and system types.

You can watch the session here anytime on your time

Watch our intro to Solar Shingles: The best re-roofing & new roofing option for a home.

Continuing education is available for both of these as well

GHI needs continued support to keep this session going into 2025 and beyond. Please help us reach our goal of 400 members and get instant access to all our live webinars, with no registration and free on-demand CEUS plus more benefits. Learn more and register here.

In addition, our year-end fundraiser is underway, and we need your help to reach our fundraising goal and keep these sessions going. Give now!

Stay tuned tomorrow for our continued countdown through the end of the year.

This year, we have our top 5 most viewed on-demand CEU educational webinars and our top 5 most live-attended webinars.

Coming in at #3 for the on-demand most viewed course, The Basics of Passive Solar Design, and the most live attendees for the year was the All About Ducted Mini Splits v2 2024 session, which was featured as our #4 on-demand session in the last post.

Our board director and technical committee chair, Debbie Coleman of Sun Plans, has been helping us put together our series on passive solar practices over the last few years, with this being the introductory course and including two other courses completed this year. She was joined Orlo Stitt, Passive Solar Builder.

The survey results indicate that participants gained a wealth of knowledge about passive solar design tools and techniques. They learned important principles such as the optimal thickness for mass walls, the significant potential for the sun to provide a substantial portion of a home’s heating, and strategies for maximizing passive solar heating through proper building orientation and window placement. Participants found new resources like the Solar Path Finder tool and various online solar calculators particularly helpful. However, several questions remain, including the practical application of innovative designs like the Ice House Roof in different regions and the compatibility of passive solar strategies with local building codes. Additionally, some attendees expressed a desire to further explore the nuances of passive solar design technology and its integration with weatherization practices.

Watch this session here, anytime, on your time! 

Continuing education is available for both of these as well.

GHI needs continued support to keep this session going into 2025 and beyond. Please help us reach our goal of 400 members and get instant access to all our live webinars, with no registration and free on-demand CEUS plus more benefits. Learn more and register here.

In addition, our year-end fundraiser is underway, and we need your help to reach our fundraising goal and keep these sessions going. Give now!

See Number 4 Here.

Stay tuned tomorrow for our continued countdown through the end of the year.

This year, we have our top 5 most viewed on-demand CEU educational webinars and our top 5 most live-attended webinars.

Coming in at #4 are both courses we hosted this year on Heat Pumps. There is no doubt a growing interest in heat pump technology to heat the air and water and cool the air in the summer. All while using the air to do it! Heat pumps use no unhealthy combustion onsite and can be powered with all renewable energy. There are many new tax credits and incentives available for them. 

For on-demand, the most viewed is All About Ducted Mini Splits (v2) 2024, and the 4th most live-attended session was 120v Plugin Heat Pump Water Heaters: Insights from the field.

Continuing education is available for both of these as well

GHI needs continued support to keep this session going into 2025 and beyond. Please help us reach our goal of 400 members and get instant access to all our live webinars, with no registration and free on-demand CEUS plus more benefits. Learn more and register here.

In addition, our year-end fundraiser is underway, and we need your help to reach our fundraising goal and keep these sessions going. Give now!

See Number 5 Here.

Stay tuned tomorrow for our continued countdown through the end of the year.

We have our top 5 most viewed on-demand CEU educational webinars and our top 5 most live-attended webinars this year.

Coming in at number 5 for our on-demand most viewed webinar is

“There is no such thing as a free thermodynamic lunch,” and most live attendees was “Intro to Heat Pump Sizing With The New Manual H”

We were honored to have building scientist Joseph Lstiburek join us in teaching this course. Here is a summary of what survey attendees had to say.

From the survey results, participants gained a deeper understanding of building science principles, particularly regarding moisture control, insulation strategies, and the importance of proper construction practices. Many expressed surprise at the nuances of insulation placement and the significant thermal conductivity of steel studs compared to wood. A recurring theme was the critical role of moisture movement and air sealing, with numerous lessons on achieving optimal wall and roof designs in various climates. Despite the wealth of information shared, questions remain about the specific implications of building in different environments, best materials for various applications, and further clarification on the use of vented versus unvented attics. Overall, the session resonated with many, providing both foundational knowledge and prompting curiosity for continued learning in building practices.

You can watch the session here anytime on your time

Watch our intro to heat pump sizing here anytime

Continuing education is available for both of these as well

GHI needs continued support to keep this session going into 2025 and beyond. Please help us reach our goal of 400 members and get instant access to all our live webinars, with no registration and free on-demand CEUS plus more benefits. Learn more and register here.

In addition, our year-end fundraiser is underway, and we need your help to reach our fundraising goal and keep these sessions going. Give now!

Stay tuned tomorrow for our continued count down through the end of the year.

Stay up to date in real-time by following #GreenHomeJobAlert on LinkedIn. 

• Various positions, Northeast Energy Efficiency Partnerships, NE/MId-Atlantic region
• Vice President of Green Lending, Enterprise, hybrid
• Director of Credit and Compliance, Enterprise, hybrid
• Data Program Officer, Enterprise, hybrid
• Senior Loan Officer, Enterprise, hybrid
• Decarbonization Project Manager – Community Programs, Elevate, MI
• Intermediate Full Stack Developer, HAVEN IAQ, Vancouver BC Canada
• General Manager, Elephant Energy, Denver CO
• General Manager, Elephant Energy, Boston MA
• RESNET QA Compliance Specialists, Residential Energy Services Network, East-West-Central-Gulf regions
• Senior Project Consultant – Community Consulting, Elevate, Chicago IL
• Production Manager, Attic Queen
• Senior Associate – Building Decarbonization, Utah Clean Energy, Salt Lake City UT
• Program Manager, Sealed, Remote
• EMU Sales Lead, EMU, Remote work for residents of Colorado, New York, or Wyoming
• Principal Engineer – Distributed Energy Resources, GTI, Hybrid IL
• Senior Analyst, Building Energy Codes, ACEEE, Remote
• Builder Sales Representative, RNC, Aeroseal, PA, NJ, and NY

Success Coach (Case Manager), NEHERS, Remote, Prefer MA-Based

EMU Passive House Sales Rep

Embodied Carbon / Upfront Carbon / Embodied Energy, call it what you will, is the energy and carbon all burned up and used before the newly built home or renovated home even started operating. As operating energy starts to go down (aka your utility bills) with electrification, heat pumps, solar, and renewables on the grid, it is clear embodied carbon will make up the vast majority of carbon now emitted for new homes, buildings or remodeling projects. It is important we tackle this growing concern in an effective way, but how do we measure it?

 

Our GreenStar Homes Certification program is one of the first green building programs that requires new homes to have their embodied carbon reviewed in the Certified level and also reduced in the Silver, Gold, and Platinum levels.

 

We offer different tools and guidance on how to do this with the measure’s details here.

However, I know the industry is overloaded with so many tools. What if we had an all-in-one unified tool for home energy ratings, scores, carbon, and embodied carbon?

 

That is why we are excited to see the industry’s leading Home Energy Rating System open up public comment to add embodied carbon to it.

 

Imagine if when the rater did your preliminary rating, it could also provide your projected embodied carbo,n and you could make informed design decisions about how to change your product selections to get the best trade-off of lower embodied carbon, lower operational carbon, and lower utility bills all while complying with your needed HERS rating for code, green programs, utility funds and or IRA tax credits.

 

Well, we are getting closer to that reality!

 

“RESNET® releases draft PDS-01 of RESNET 1550, Embodied Carbon, for public review and comment. The standard provides a consistent methodology for the calculation and reporting of the embodied carbon of dwelling and sleeping units. The standard defines the scope for calculating embodied carbon and a methodology for conducting the calculations that uses the same modeling data and processes and reporting employed by standard ANSI/RESNET/ICC 301. Comments will be accepted only on text in draft PDS-01 shown by strike-through and underline and in red print. To review and comment on the Draft follow the links below. The public comment period begins November 22, 2024, and ends January 21, 2025.”

Please comment here with your thoughts and help make this a beneficial reality so we can transform the housing sector and make homes, BETTER.

Saving water is important; however, when it comes to total home health, we also need to consider more than water quantity in green.

A point-of-use reverse osmosis (RO) system is designed to filter water at a specific location, like under your kitchen sink, using pressure to push water through a semi-permeable membrane. This process removes various harmful contaminants such as lead, PFAS, bacteria, and viruses. While these systems are great for improving water quality, they do waste a significant amount of water—often five gallons or more for every gallon treated. However, models labeled with WaterSense are more efficient, producing just 2.3 gallons of waste per gallon of treated water.

 

Though the water from public suppliers in the US is generally safe, some people may want extra treatment, especially for well water. WaterSense doesn’t endorse RO systems for every situation, as other methods, like filtration, might be enough and waste less water. For those considering a new RO system, WaterSense-labeled models can save over 3,100 gallons per year, leading to substantial water savings nationwide.

 

Performance-wise, WaterSense systems are certified to meet specific criteria, ensuring they effectively reduce contaminants and maintain the membrane’s lifespan. The EPA has established specifications for these systems, which will be discussed at an upcoming virtual public meeting on Dec 17th: register here.

While most of the residential green building programs disregard RO and do not award for it or consider it, the GreenHome Institute GreenStar Homes Certification requires water filtration at the Gold level of our certification or for the Healthier Home badge. Go here to learn about what is required and get educated on why we can’t just think about air quality but also must think about water quality for total home health. The GreenStar program’s Home Water Score calculator was recently updated to be more accurate for projected water usage. What’s your Home Water Score for your home or latest project?

What if we added insulation on every re-siding job?

 The “doing this while doing that” concept is one of the best incremental ways to advance sustainability in existing homes. For example, when replacing water fixtures, get low-flow WaterSense certified; when upgrading appliances, go quiet, select ENERGY STAR certified appliances and switch to all-electric; and when needing a new A/C, opt for a Heat Pump instead, which can be standalone or paired with an existing gas furnace.

 Now, a new movement is well underway, led by the US Pacific Northwest National Laboratory (PNNL). Its acronym is AIRS, which stands for Adding Insulation While Residing. The idea is simple: every time a home or building needs to be resided, we should ensure that it is also getting continuous exterior insulation added. The insulation can be foam, mineral wool, or even wood fiber. Most re-siding companies need to start doing this, and most weatherization programs prefer to drill and fill the walls instead of adding continuous exterior insulation.
 The GreenHome Institute is proud to be a PNNL funding recipient to administer this research project here in Michigan. Before taking on the program, we launched a 1-hour continuing education session on the topic. We are looking at researching this approach on at least nine homes and now have our first project completed to share some initial information.
 

The first thought might be energy efficiency, utility bill savings, and comfort for the owners or tenants of homes that get AIRS. However, additional important benefits of this work are the reduction of wall moisture issues and durability risk reduction. In fact, many siding jobs are not taking this opportunity, leaving in place moisture risks that are reducing the life of the walls and homes due to deficient construction and renovation practices. To illustrate this, you can see the Building Science Advisor (BSA) tool evaluation we did on the previous wall assembly versus the new one here. Here is a CEU webinar we did on the Building Science Advisor tool.

According to the BSA tool, adding 1 inch of Owens Corning EXTRUDED POLYSTYRENE (XPS) continuous exterior insulation to this first test home significantly reduced the risk of wall sheathing moisture content and mold.

 

We suggested that the siding contractors add two inches of insulation, but they were fairly resistant to that idea – which is what this research project is about. Trying to convince siding contractors that adding insulation is important is going to take a lot of work. Adding more insulation requires more effort from the installer.  Design conversations will happen, and they will be different for each home.

 

However, let’s look at the wall’s durability. If we had added the additional one inch as advised in Climate Zone 5, you can see that scenario versus the two inches suggested below, which moves it from a potential sheathing risk to the light green zone of reduced risk. 

From an energy efficiency standpoint, each home we work with receives a GreenHome Inspection before and after work is completed. This process includes reviewing many components of the home. Still, the focus of this program is to give the home and overall US DOE Home Energy Score and determine the home’s air leakage and total energy usage before and after the retrofit. For this particular home, the overall score went from a 4 to a 6, which included over $100 in utility savings and nearly 15 members in total energy reduced both in heating and cooling, which was the result of the exterior rigid being added, three windows being replaced, and a 22% air leakage reduction. If you do the math, that is a 13% savings in energy usage, which gets us pretty close to the savings needed for the Inflation Reduction Act State HOMES rebates of 15% in measured savings needed to get $4-$8k in rebates.   

Not only are energy and money being saved, but the owner also said, “I’ll add that aesthetically, the house looks great. From a functional standpoint, my wife and I definitely have noticed that the two bedrooms that previously felt colder than the rest of the house feel much more comfortable.”

 

The other aspect of our GreenHome Inspection included reviewing ventilation systems. With a tighter home, we need to see if ventilation needs to be improved to optimize occupant health when these jobs are being completed.

 

Stay tuned as we report on the eight additional homes. Note that PNNL will be releasing case studies on these homes. Two GreenHome Institute members have already completed an AIRS study on their homes. One case study is forthcoming, and the other, which you can find here, was done by Tom at Builder World Builders.

Please review part 1 of this series, then continue below

 The remainder of this series will describe what makes LEED a challenge as well as what makes LEED easier on existing homes projects.

 The ENERGY STAR Homes program is an ideal goal for all major renovation projects to strive for, but it can be very difficult to meet if there is no plan or budget to change certain features. Reviewing the ENERGY STAR thermal enclosure checklist, here are the exceptions granted:

1. High-Performance Fenestration not required for existing windows that are not being replaced
2. High-Performance Insulation not required for existing walls that aren’t impacted by the renovation.
3. Slab insulation is strongly encouraged but not required to meet or exceed 2009 IECC levels.
4. Attic insulation at the intersection of existing roof and existing exterior walls does not have to meet R-value requirements.
5. Advanced framing is not required on existing framed walls,
6. For insulated ceilings with attic space above (i.e., non-cathedralized), Grade I insulation extends to the inside face of the exterior wall below and is ≥ R-21 in CZ 1-5; ≥ R-30 in CZ 6-8.
7. Air Barrier is needed except for Existing sill plates on top of concrete are not required to be placed on a foam gasket.

 Review technical details here:

https://basc.pnnl.gov/checklists/energy-star-single-family-new-homes-version-331-revision-11

Insulate and airseal rim band joists

 

Garage pollution protection can be achieved while creating the air barrier

 Place all air-handling equipment and ductwork outside the fire-rated envelope of the garage. Tightly seal shared surfaces between the garage and conditioned spaces, including all of the following:

• In conditioned spaces above the garage, seal all penetrations and all connecting floor and ceiling joist bays.
• In conditioned spaces next to the garage, weather-strip all doors, install carbon monoxide detectors in rooms that share a door with the garage, seal all penetrations, and seal all cracks at the base of the walls.Watch out for CO detectors, too, if they are not near the garage, and the electrician may need to wire one near the garage. You may be able to get an exception for battery backup only if there is no easy way to wire it. Check with your provider at the start of the project.

 Put together an air seal and insulation plan with your contractor and submit it to your LEED Residential Provider to ensure it is sufficient. This is mandatory for all midrise multifamily buildings.

 What do I do with mechanical and HVAC?

 The next biggest barrier to achieving LEED in older homes is an energy-efficient, properly functioning, and commissioned HVAC and mechanical system. This includes proper sizing, proper functions, proper air filtration, and well-sealed ductwork to deliver air.

 One of the biggest HVAC barriers to achieving LEED certification in older homes is ensuring there is no panned ductwork in the floor or wall joists. Ensuring this does not happen improves the Energy Rating Index, or HERS. Any existing home found to have this ductwork panned anywhere on the floors, walls, or attic must be re-ducted. This may require the drywall to be torn out and redone, which can be costly.

 Another option is to use the existing ductwork for a ventilation system, which negates the need to have it fully ducted, though this is still recommended. Then, consider radiant or ductless mini splits for heating and cooling.

 *Note that getting a mini split might not resolve humidity issues either, so there are bonus credits in v4.1 Residential for products like dehumidification or ventilating dehumidifiers. These will reduce the humidity issues that are not resolved by mini splits. Also, existing homes suffer more from humidity issues than new homes.

 If the system must be replaced with a new ducted HVAC system, it must be correctly sized. This is a good way to seal the ductwork; this can be done as the ducts are being rebuilt if they were panned in the joists; some technologies seal existing ductwork from the inside. If the filter box is one inch, you can add a MERV 8 filter or higher (10 for additional points), but the static pressure of the system will need to be checked; otherwise, if getting a new HVAC system, consider adding a 4-inch filter to reduce static pressure and improve system performance. Getting a new HVAC system will also help you get a better energy rating, and many Inflation Reduction Act tax credits apply in the US. Consider a heat pump to get the funding and achieve the best energy rating with lower utility bills in many cases.

 In summary, commissioned, right-sized HVAC systems with reduced duct leakage and good filtration are important. During the LEED preliminary rating, the HVAC contractor can measure the size of the current system and complete the HVAC design report relevant to the planned home energy upgrades to determine if it is oversized using the ENERGY STAR guidance.
Stay tuned for next month’s Part 3 LEED Renovation Durability and Healthy Home Opportunities.