How TBDA Uses Passive House To Design Better Buildings

December 6, 2019

Passive House is more than an energy standard—it’s a way of understanding the technology of high-performance building, and it allows architects to optimize a building’s performance through the design process, regardless of whether an owner wants to pursue certification or not.

The “business-as-usual” approach to design is to focus on program and appearance, then have an engineer or contractor size mechanical systems to condition the building; more sensitive designers may take into account sun angles and daylighting, but for many designers these are afterthoughts as well. That approach usually leads to needless energy consumption, glare, overheating, and thermal bridging. Our approach is to use the powerful Passive House modeling tool to tune the building to the climate as an integral part of the design process.

We begin design with an analysis of climate (temperatures, humidity, sun, rain/snow, wind), vistas and sense of prospect or “belonging” on the site, topography, and neighborhood or natural setting, all to allow the building to speak the language of the site. I think of it as imagining a living thing that evolved to live in that place—its feet or roots in the ground, its back to shelter, its face to the sun, with the right brows, whiskers, or foliage, as the metaphor may be!

That leads to initial gestural designs that become building shapes. As soon as we settle on a general layout, we then bring that geometry into our Passive House (PHIUS) modeling software (called WUFI-Passive), where we can enter values for insulation, window size, orientation, and performance, mechanical system performance, and internal energy use. By trying out different values for these, and by trying different approaches to shading and exposure, we can arrive at an optimal performance level for the building.

Part of the beauty of the PHIUS standard is that the climate-specific metrics give definite targets to design toward. When we optimize for both heating and cooling loads, we set the stage for comfort; when we minimize overall energy (efficient mechanical system, lighting, and appliances), we can design a project to meet annual net zero energy with the smallest solar PV array possible. And from a design point of view, we know the building will have a climatic “fit” that will allow the building to feel true to place.

If there’s one absolute I go by, it’s that Nature is right. I use the PHIUS tools and knowledge to allow my designs have an organic approach to energy, just as I employ biophilic design and understanding of the locality to allow the designs to have an organic, natural countenance and fit with the site. We’re pursuing ecological architecture through both art and science.

Vision

January 9, 2019

TBDA’s vision is to design a healthy, beautiful, low-carbon future.

We’re a service profession, so the core of what we do is design buildings where people live, work, and play; but our vision is the attitude and purpose we bring to that service, the reason you would hire or work for us instead of the next firm.

Let’s look at these values—healthy, beautiful, low-carbon–in a little more detail. How do we incorporate these into our work?

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From the Field: Literally (House on a Prairie Site)

May 11, 2017

This is one of those dream projects: great client, great site, and a design that just fell together naturally. And the team at Mike Von Behren Builders is fantastic–really getting into the project and executing beautifully. As one of our first larger rural projects, this was an opportunity to incorporate larger site moves, and let building and site development embrace the flow of water as well as sun, wind, and views. Our approach has been to use biophilic design principles to shape the project, such as prospect and refuge (for siting and layout), visual connection to nature (not a great challenge on this site!), and presence of water, while conceiving of the architecture as an integral part of the site. (more…)

Architecture and Health

July 29, 2015

The interaction of the built environment and human health has been a topic of great debate and much development lately. Between the Well Building Standard and the Living Building Challenge, we have new ways of thinking about and measuring our successes and failures in building healthy environments. I encourage everyone to go and read up on those standards, but today I wanted to bring my own angle to the topic. As a follower of the ancestral health movement, I’d like to look at environmental health from an evolutionary perspective, and through an architect’s eye.

First off, the obvious: to quote my favorite blogger Mark Sisson, “avoid poisonous things.” No species would survive long if it chose toxic environments. Yet, sadly, our building industry is chock full of poisons, and it is only with great diligence on the part of architect and builder that low toxicity can be ensured. On top of “clean” materials, it is important to ventilate well, which is a lesson that Passive House teaches. In a tipi or cave, there’s plenty of fresh air (well, smoke too, let’s not romanticize too much here); we need it in our buildings too!

Not doing harm is a necessary first step, but it’s only a start. We must provide positive, nurturing environments! This gets into a newer and more subtle field. When we spent most of our time as a species outdoors, we were tuned to the sights, sounds, textures, and smells of the environment; such sensory engagement, and with natural forces, is a far cry from most indoor environments. On top of that, we were moving, not still–not living a dangerously sedentary lifestyle. And finally, from Jay Appleton to Grant Hildebrand, there is a persistent notion that we as a species seek “prospect and refuge” in our landscapes and environments: we instinctively want a combination of safety and opportunity.

So here’s the big question: how do we design buildings that provide prospect and refuge while keeping people active and in tune with natural forces and sensory input? (Easy answer: send them outdoors! Well…OK, not into that parking lot there, but the woods 35 miles away…OK, not an easy answer after all.) There is a whole field of inquiry seeking to answer this question, that of Biophilic Design, but I’m going to take a shot at answering more simply:

  1. First, think of the building and site as habitat, not merely a functional package (machine) or fashion plate (trend). But design it beautifully, as an organic whole, an inspiring place.
  2. Second, as habitat, avoid all toxins in construction! Now to the psychological and design aspects:
  3. Provide vista: long views, even if only to sky, must be integral to the experience of place.
  4. Along with vista, balance natural light throughout the space, so that it comes from different directions, allowing one to sense the movement of the sun and appreciate the natural textures inside (see #8) as light reflects off of and rakes across them.
  5. Provide strong sense of shelter and “edges” (gateway, transitions) bounding the habitat. The demarcation of inside/outside should correspond not to the building walls, but to the boundary of habitat. Think of monasteries (cloisters), farmyards, garden walls–a sense that habitation is not just shut up inside a building, but designed to extend outdoors.
  6. Provide access to plants, animals, and moving water. A garden to cultivate, indoor plants, pets, birdhouses, livestock, a fountain or stream…the health benefits of these alone are manifold.
  7. Encourage outdoor experience by designing patios, screen porch, etc. into the flow of a building (a living habitat edge).
  8. Use natural materials as enclosure and finish, and if employing a decorative level of finish, use natural patterns–I know that’s vague, but it is a worthwhile avenue to pursue. There is a reason Wright’s stained glass windows have enduring appeal, and I think it’s the “nature-pattern” richness of the work more than anything else. Homage to Mother Nature.
As I limit myself to 8 points, I know I’ll be adding to or editing these in the future! But I think it’s a good start. In coming weeks, I will show some examples of work embodying these 8 design fundamentals. Obviously these are for smaller buildings, not high rises, but they are broadly applicable. The result is a natural, nourishing, lovable environment in harmony with its place. Why should we accept anything less?
Tom Bassett-Dilley Architects | Contact