Are We Ready for Better Buildings?
I recently had a phone conversation with a frantic contractor who was in charge of a Passive House (PH) retrofit. He was in desperate need of an air-sealing specialist. The house was leaking almost a 700 CFM50 more than the required 0.6 AHC50 for a PH. The house was listed and staged, beautiful and ready for a market sale of over $8 million.
After a series of questions over the phone, I was baffled as to how they were going to fix their air leakage problem. It was obvious that they had buried their leaks behind crown molding and three coats of latex, and to access them now would mean tearing out walls. I have seen this type of thing happen quite a few times in past years. This incident is an air-sealing problem on one particular job, but it shows how the entire building team can be disconnected.
In a PH, the 0.6 ACH50 is the absolute and required number to hit. In order to achieve that, the entire building team has to be united and educated on the goal—education being the key word here.
The PH Mind-Set
House assembly over the centuries has evolved into a collection of trades that work to produce the finished product. It starts with the architect picking out the latest and greatest, greenest and leanest products to fit his or her design and assumes that if they are cutting edge, they will produce a cutting-edge home. “Old-school building” technique only requires that each person on the job understand his or her skill set, so even in the case of a PH assembly, if you bring in a very smart and highly skilled old-school team, you could wind up with a fragmented and misunderstood assembly.
The reason I like the PH mind-set is that the assembly, the organism, the whole house, was pioneered by a team of physicists and innovators who used absolute scientific values that had to be synchronized in order to make all the parts building work together. The values are listed as to their specific energy loss and or gain in the thermal envelope. They call the collection of values, the Passive House Planning Package (PHPP). It’s a spreadsheet that keeps all the parts and values in balance to produce a specific super-low-energy budget with the fallout of an amazingly good indoor air quality along with flat-line thermal comfort.
To understand how this might look, picture an old-fashioned balance scale. The entire scale (house) is the project. Each side is loaded with human input, parts, and labor. The goal is to keep the pointer hitting the zero in the center. If you take a value off of one side, it will go wonky, and you have to equalize it on the other side with another value or part to get back to zero. The pointer at zero represents the kind of practical stuff people value in a house—thermal comfort in every part of the building envelope, ease of operation, durability, accessible and simple working parts, and the least possible off-site energy as the source for heating and cooling. In PH calculations, it is not so important what is on which side of the scale, just as long as you can get that pointer to near zero (net zero).
The challenge with the PH formula is that it requires a team of designers and builders who understand how to achieve this and are adept and synchronized at doing so.
For me, the critical part of assembling a high-performance building (HPB) is inspiration. An inspired and educated worker is a powerful asset to have on your job. As a contractor/builder or architect, you can control your team. You can shop around for an inspired and educated team. If you like your current crew and they are not educated in high-performance building (HPB) or PH, make it a requirement for them to be trained.
PH and HPB are A-to-Z path-completion projects. The team needs to understand that path. By offering the prize (a new, certified, near net zero building) before the work commences, we often forget what it takes to get there: education and retraining . . . and hopefully, inspiration.
I have seen too many times where the PHPP person hands down a gorgeous spreadsheet of prescribed measures to an old-school contractor who may not fully understand the goals and process. It is not necessarily the PHPP person or the architect’s job to supervise the high performance measures to make sure it comes out right, so if the contractor and job supervisor are not educated in whole-house theory, chances are the assembly is not going to perform as designed.
PH building is very close to old-school building, but it’s different enough that if you get a few of the tracks wrong, it can wreck the entire train. Here are some tips to build a better house and avoid a train wreck:
- It is the foreman’s or the contractor’s job to keep the flame of inspiration going on a job.
- The entire crew should go through some kind of training before the job starts.
- The crew has to know that they are as much a part of the end glory as the contractor.
- There has to be at least one person on the job who is well schooled in PH or HPB.
- The PH or HPB measures must be on the working plans.
- There has to be an air-sealing specialist on the job who is responsible for all the air sealing.
It would also be great if there were meetings with the crew and the subcontractors to unify the vision and goals.
In this day and age of speedy expectations, I realize it is a lot to ask that a builder or architect or carpenter take the time to learn something new, but compared to the three-year apprenticeship that was expected a few generations ago, is it asking too much? It is time that we build in a few hours on an $8 million job to train our contractors and our crews to do the job right, and inspire them to build the buildings we should be building.
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