Synergies: Let’s Be Independent, Together
Entering into the world of systems thinking, I’ve come to realize that we could be paying much more attention to synergies, to co-benefits and to true interdependence.
First, a reminder; Interdependence is strength. We start as dependent babies, needing all from others. We then gradually learn and grow and make mistakes and learn some more, and become independent. Most of us stop there. Independence is not only a national ideal but a mantra for everyone leaving home and starting their adult lives. Well, it’s hooey. It is only the adolescent stage of development. True strength comes from interdependence. Development of relationships, communities, families of all shapes and sizes, and a recognition of abilities and missing abilities that can be completed by interaction and interdependence with others. As Hermey the dentist says, “Let’s be independent, together”, and it is in collaboration that Rudolf, Yukon Cornelius and Hermey all grow into their most successful beings, save Christmas, and find out the Bumble is a sweetheart.
So there are three pieces to this interdependence, really. I’m definitely going to mix my analogies, here. Team blue (Mystic) is that the building has to work with itself, and many don’t. Many buildings have leaky walls that undermine poorly designed HVAC systems, or they face the wrong direction and allow too much uncontrolled heat gain. Team yellow (Instinct) is the piece where the building needs to commune with its surroundings in order to benefit from wind, sun, rain, flora and fauna and soil conditions. Team red (Valor) strives for interdependence between the building and its users so they know how to manage the building and benefit from its capabilities and quirks, and so the building can have the breadth of parameters to respond well. And it takes all of these teams to make the game fun and successful.
So here we will talk about building envelopes. Let’s sail into the Mystic.
We have undervalued building envelopes on their own, and their collaborative success with energy MEP systems, and with user comfort. For some reason we think it is enough to heat and cool a crap building, but all this does is give us moments of comfort mixed in with the discomfort. Not sustainable, and not interdependent and not successful. Certainly not optimized.
More and more we are paying attention (needed attention) to the building envelope: the walls, roof, floors, fenestrations and penetrations. NY state Energy Code is doing it better, by testing for tightness and performance in the new residential energy code, and by very clear detailing in the commercial code. Passive House is certainly doing it by maximizing the insulation and sealing and then properly managing the ventilation to optimize healthy air, and LEEDv4 now includes building envelope commissioning…we should all be paying attention. The building walls, floor and roof are part of the energy system, after all.
Wait, what? The envelope is not part of the energy system! it doesn’t take in energy or use energy or produce any energy! Wrong.
This is really what we need to comprehend if we are to have any hope of net positive buildings in our future, or even non-wasteful buildings in our present. The building envelope gains heat by solar heat gain through windows, thermal storage by sun beating on the materials, and by the maintenance, through thermal storage, of heat created within the building. Using materials that can store het longer and thereby lengthen the curve of heat gain and loss will help with energy control, and is a viable energy system akin to any radiant system or off-peak ice storage plan. Designing the fenestrations to be very low in leakage and to optimize timing and amount of heat gain is also an energy production system, and one that can offset most of a building’s heating load if well done. The most powerful aspect of a well designed building envelope is its ability to act as a thermos, keeping the heat in the volume of air contained in the building. Tighter is always better so long as we then mechanically ventilate properly to control air quality. And note, there is another important aspect here that is only really discussed in passive house approaches and in selected credits in LEED. If the building is tight, tight, tight, you damn well better select clean and non-toxic, non-off gassing materials for that building envelope to reduce burden to the air quality control. We must all learn that avoiding energy use is the best and most cost-effective form of fossil fuel displacement, so much more effective overall than renewable energy purchases or even RE on-site.
Design well, understanding the use of windows and doors and where they can be placed and how they operate as well as the quality of glazing and how/if you can benefit from solar heat gain. Always remember that the best window is totally crappy in holding energy in compared to a wall. We need windows for view and daylight, but they need to be placed well and limited to about 30% of the wall area. Reduce corners and bump-outs where you can while you are working on good space design and appearance. This allows for fewer mistakes in making the absolutely needed continuous air barrier – continuous around the building and up and down and around every bend. Then make all the walls highly insulated and well detailed to eliminate leaks and thermal bleeds (ex of a thermal bleed? a metal shelf angles helping heat to race out of the building). And pick materials, including insulation and interior finishes, that will handle water intrusion well, will reduce or eliminate concerns about off gassing and toxins, and will be durable over time. Aim for durability in exterior finishes that can handle even broad freeze/thaw cycles and in changes between beating sun and dark shade. This is the way to build your often overlooked energy system: the building envelope.
The building envelope, if dealt with as an energy system, can help you to downsize the energy driven systems, which will save money, reduce fossil fuels and create higher resiliency in your building. Remember, Rudolf needed Hermey to find the misfit toys, and there would be no battle if it were only Mystic out there looking for Pokemon. Interdependence rules. It helps us to survive and it makes surviving fun.
Be green, and interdependent,