When most Americans envision a new home, they do not envision it being delivered by a flat-bed truck. But factory built, pre-fabricated homes, like the ones at Michelle Kaufman Designs, could be the wave of a sustainable, well-designed future. I invited my best friend, Molly McGrath, an architect at MKD, over to my totally unsustainable house in Oakland to ask her about her work, and why pre-fab means green.
Q: What is a pre-fabrication?
A: Pre-fabrication (pre-fab) is a process of building a house, or parts of a house, in a factory, as opposed to building on a site. There are a many different types of pre-fabrication. Component construction is where you make certain components in the factory, like roof trusses, and ship them to a site to be included in the building. With panelized construction, you might build entire walls or floors in the factory and then ship those out to be assembled onsite.
Another type of pre-fab is manufactured housing, which is what most people associate with trailer homes and pre-fab. These houses are required to comply with HUD (Housing and Urban Development) code, which is usually less stringent than the local and state building codes to which our homes must adhere.
At MKD (Michelle Kaufman Designs), we do modular construction, which is similar to manufactured housing, in that we are building the majority of the house in the factory. It is different because we have to comply with the same state and local codes that site-built homes have to comply with. Visually, it is difficult to discern a modular home from a site-built home.
So, first we build the modules in the factory—plumbing, electricity, framing, roof—and then ship those modules to the site. Our homes are usually composed of one or more modules placed on a site-built foundation.
Q: Why is pre-fab a more green way of building than building a home on a site?
A: Many facets make pre-fab modular construction a more sustainable way to build. With pre-fab, there is more quality control because you are building in a controlled factory environment versus being out in a site where weather, dirt, etc. can affect the quality of construction. There is less waste because any excess material you have can be used for future projects, whereas on a construction site, this excess is likely to be discarded. Pre-fab is also a more efficient and faster way to build, since everything is assembled in the factory.
At MKD, we also spec [use] as many sustainable materials as possible.
Q: Like what?
A: The wood we use for cabinetry and flooring is FSC (forestry steward council) certified, which means it has been grown in a sustainably managed forest. We use finished materials composed of recycled content, like paperstone countertops and recycled glass tiles. We use low-e glass in our windows and doors and place them in such a way to maximize cross ventilation, which reduces the need for air conditioning.
We encourage water conservation by using low flow toilets, low flow shower heads, and on-demand water heaters. The insulation we use in the houses is a spray-in foam called isonene, which is good for a couple of reasons. It is nontoxic. Other forms of insulation have fiberglass in them, which is not only hazardous for workers when building but also when demolishing a house. Because the isonene is a spray, it fills in an entire cavity so it allows no air pockets. No air pockets mean better insulation and a reduced chance for mold to develop.
Q: How are these houses installed on a site?
A: While they are being built in the factory, the foundation is being built on the site. A flat bed drives to the factory, picks up the module, and then drives to the site. The module or modules are lifted on the site in one of two ways: rolls set or crane lifted. Roll set is used when the foundation and truck are level with each other. Steel beams from the flat bed are put onto the foundation, and then these little, incredibly dense rubber pillows are placed on all four corners of the foundation. The module is slid or rolled onto the foundation, the steel beams are taken out, and you slowly let the air out of the pillows.
Q: That sounds dicey …
A: Yea, it sounds like it, but it works really well. For more sloped sites, you use a crane. The crane lifts the modules via incredibly strong hoisting straps and onto the foundation.
Q: What are the different types of houses you have?
A: We have four houses: Glidehouse, Breezehouse, Sidebreeze, and the mkSolaire.
The Glidehouse was the first house Michelle designed and she and her husband built it themselves. There is a lot of attention placed on the details. It consists of a series of 14-foot modules: shallow buildings with glazing on both sides, maximizing natural light, and reducing the need for artificial lighting. The signature architectural feature of the house is the gliding wood sunshades, which naturally mediate most of the light and breezes in the house.
While building it themselves, a couple of friends expressed interest in the design and they decided to try and build one in a factory. The process was speedier and less expensive, and there was so much interest in these pre-fab Glides that Michelle decided to base her architectural practice around sustainable modular homes that provided an alternative to the standard cookie-cutter subdivision.
The next house that MKD came out with was the Sunset Breezehouse, which is composed of a two bars of 14-foot modules with a large 18- to 24-foot wide “Breezespace” in between. The Breezehouse was designed for clients who wanted a more spacious layout than the Glidehouse. People can spill out from one of the bars into the Breezespace. It gives the feel of having a lot of space. The Sidebreeze is a two-story bar of modules with a Breezespace attached at the side. It is designed for people with narrow lots.
The mkSolaire is a design that addresses the urban condition. It rethinks the rowhouse, by bringing in light in ways that typical row houses do not; via a wind and light catcher on top, which funnels wind and light to the bottom floors. It has some double height spaces, giving it a lofty, open feel.
Q: If all the houses are constructed from the same set of modules, what is your function as an architect design-wise?
A: We have the three main types of houses at MKD, these are the standards. (Glidehouse, Breezehouse, mkSolaire) We also do custom projects for clients that want pre-fab but don’t want a standard. This is the avenue at MKD where you get to design the most. It is like doing a site-built house, but you are working with the fact that the components of the house are modular. This really becomes less of a design issue, and more of a construction issue. I think the best custom houses are those which were not looking at the modules as an after thought, but considering them in the process of design.
The other way that we design in the standard house process is by figuring out how each house will fit on each piece of property. Clients come to us with really unique sites, views, sunlight, neighbors, wind—all of which plays a huge role in how the house fits in with the natural environment. We take all of these things into consideration when we design the house.
We offer a handbook of finishes that clients can choose from, so all the houses are customized in that sense. Sometimes it can be overwhelming for the client to choose all the finishes, so it is an art in steering them in the direction that they want, but also figuring out the most beautiful combination of finishes. It pays to look at the room as an integral part of the house, and how all the finishes work together. This can be tricky. We also come out with a new prototype every year, so we get to help design that.
Q: Do you see a shift away from the tract homes to pre-fab?
A: Some tract homes have pre-fab components; the two aren’t mutually exclusive. What tract homes aren’t is well designed and sustainable. That is what we are trying to introduce. What we do right now for the most part are pre-fab prototypes on an individual piece of land, not built as subdivisions. In order for pre-fab to be really green, you need to mass produce it, you need large scale. And our houses are designed to be replicated on that scale. People want the standard, ugly, cookie cutter track home, because that is what they know. It is what is being built by developers, and developers are building them because they are the cheapest thing to build.
Right now, factories have the capacity to build architect-designed pre-fab homes, but they don’t have the audience, though that is starting to happen. Architects are collaborating with developers and factories, to package and produce these homes on a large scale. This is what we are aspiring to do. We have something different that would make people pause and say, hey, that is different, and that is something better.
Q: Why did you want to work at MKD?
A: I wanted to work here because I believe in the mission of providing affordable, sustainable alternatives to subdivisions, and that this type of housing should be well designed. I think it is good to be working toward something that is bigger than you are, rather than just designing something according to your aesthetics, that will have a minimal impact in the grand scheme of things. Maybe it will make you personally happy, but will not make that big of a difference. I feel that pre-fabricated modular green design has the potential to make a huge difference.
Photo courtesy of Michelle Kaufman Designs