Our Path to Choosing Green Building Certifications: A Passive House and Earthcraft Home Renovation

Posted by: SawHorse, Inc. // SawHorse Design + Build

Our video conversation above, part of the full "Behind the Walls" webinar playlist, shows how the Passive House Standard far exceeds basic energy codes.  When we first started the design process on the #1920sMakeoverATL, a deep energy retrofit of a charming 1920's home in the Ansley Park area of Atlanta, we were not thinking about making this house a Passive House because the only planned improvements were on the inside of the house. 

Read on to see how the project quickly evolved into a high-performance "learning house" and how our thinking about certifications evolved.  

How we chose the certifications for the #1920sMakeoverATL Deep Energy Retrofit

As a green builder, checking out green building programs is a fun part of the job.  When we first started designing the #1920sMakeoverATL, we were unsure which certifications we would ultimately pursue because we did not really know how far we would take the design (and we're still considering more).  At the time, we were primarily considering EarthCraft House Renovation since it was the only local certification that was applicable to existing houses that were not 100% gutted to the studs.  Most other programs require a deep energy retrofit, and that is not always possible and sometimes wasteful if everything has to be torn out.  Along with EarthCraft House, we were planning on creating a HERS rating to demonstrate the increase in overall efficiency.

My company, SawHorse, helped develop the first iteration of the EarthCraft House Renovation guidelines by taking the applicable concepts from the established new home program.  This was 20 years ago and was well established before LEED for Homes or other programs even existed.  EarthCraft House is also one of the certifications that feed directly into the Green Building Registry, so green agents and homeowners can see if the house is green certified.  

Plans changed quickly when we measured the house.

When we measured the house to create the existing floor plans to see what we were working with, we noticed a hole in the siding.  Usually, this is not a big deal; however, we also notice the lack of sheathing with a weather-resistant barrier (WRB), plus there was very little if any insulation in the walls.  As a green builder, we need those basic components to make the house energy efficient, yet all were missing. 

Instead of complaining about this, we presented this to our client as an opportunity to create a better house.  They embraced this opportunity since they knew the house would be much better with these extra improvements.


Fun Fact: No sheathing means that we did not have any plywood outside the stud walls.  This means no air seal, no vapor barrier, and really no water barrier beside the siding.  Even today's "barely to code-built" house has these basic control layers, which is one indication of how standard building practices have evolved over the last 100 years.  The siding was nailed directly to the studs, which were common when they originally built the house was since they were encouraged to breathe.  With a more stringent energy code, tight framing is needed to help reduce energy loss.
 

Why we added Passive House Standard to our Planned Certifications

Our architect partner, LG Squared, suggested doing a Passive House (PH), which means that we will super insulate the house, have a very tight air seal and good window and HVAC. It seemed like a fun challenge, so we decided to pursue this in addition to a few other certifications.

That lack of sheathing would require us to remove all of the cladding regardless if we were pursuing Passive House.  Once the siding is removed, the only extra step would be to add more insulation outside the sheathing before installing the siding.  We were already planning on installing high-performance windows and ducted mini-split HVAC systems with designed ventilation, so the real increase in scope was the extra insulation.  After reviewing the PH checklist, most of the required items were already in our scope of work, so it made sense to work within this standard.

This house is close to downtown Atlanta and near Piedmont Park, which means there will be extra noise from activities nearby. The extra insulation will act as a thermal barrier, making the house more energy-efficient. It will also make the house quieter and more fire-resistant.  Our insulation partner on the house is ROCKWOOL, and we are using the Comfortboard 80 behind the siding and Safe N Sound in the walls.

Once ROCKWOOL learned that we planned to design to the Passive House Standard, they hosted a webinar with LG Squared and SawHorse to discuss the current issues and optimal solutions for this project. 

Why go with a Green Building Certification?

I get asked why we even certify a house if we already have the experience to build an amazing, sustainable product without the certification.  There are many benefits to using a program as a guide to building a high-performance and sustainable house. Consider these benefits, among others: 

Continued Learning about Better Ways to Build (even for experienced builders):

These programs are always looking to find better ways for building.  You may not have the time to learn new tips and tricks or know the latest standards, so these programs are a great way to stay sharp in your craft.

A Great Way to Teach Others:

New subs and new employees don't necessarily come equipped with all of the knowledge to build the way you do.  Most of these programs have training opportunities to teach the trade and new project managers or builders how to get started.  Some programs even have classes for homeowners, so you don't have to sell them on better construction; they will expect it and appreciate it.  

Market Differentiation:

Offering a green building certification shows your client or potential buyer that you care about the house they are going to live in.  In a building climate where most builders are in a "race to the bottom" trying to provide bigger, cheaper, and faster to improve their bottom line, you are different.  You want them to live in a more comfortable, energy-efficient, healthy, and environmentally friendly house.  Most of us believe that this should be the norm; however, these programs offer us a path to better building.

Green Building Sells for More.

Studies have shown that green homes stay on the market few days and sell for more money over average than homes that do not have energy-efficient certifications.

Note: We are currently considering 5 green building certification programs for the #1920sMakeoverATL deep energy retrofit project.  We plan to do a deep dive into each of them and then go through the checklists in detail to show you which points applied to this house and which items were mandatory.  
 

If there are specific things you would like to know more about, leave a comment below.