Sustainability

Modular Construction - A Tipping Point for the Affordable Housing Industry?

For more than a decade I’ve been touting the benefits of modular construction to the affordable housing industry.  In the early years, I was trying to convince bankers that modular construction was real property – they confused modular with manufactured housing (aka mobile homes or double wides).  Then it was talking with General Contractors about how their subs would bid out the site work, and whether they would charge a premium due to decreased scope or uncertainty about scope.  And the latter few years was spent encouraging an Owner to be the pioneer – to be the first to build a multifamily affordable housing project using modules. 

 tortise and the hare

tortise and the hare

At times I felt like I was the proverbial tortoise watching the hares run by with built prototypes and talk of market rate multifamily projects. Michelle Kauffman, with her Breeze House and Glide House, opened up the single family market and suddenly prefab was perceived as cool and sustainable by the likes of the Sunset and Dwell magazine readership. When Michelle was a keynote speaker at the Housing Washington Conference [1] a few years back, I thought “wow, it’s about to tip!” But it didn’t.

Until now.

On July 23, we opened bids for Schemata’s first modular construction project. The pioneering client is the Renton Housing Authority. The project is an 18-unit 2-story multifamily project – predominantly townhomes but with four stacked flats, making the scope a perfect test case.

2013_0315 Modular Graphic-1.jpg

Modular construction means that residential units arrive on site 90% complete with interior finishes, flooring, plumbing and lighting fixtures, electrical wiring, plumbing lines, windows and even exterior cladding if you choose. The modules are trucked to the site and lifted onto a site built foundation by a mobile crane.  

 OneBuild Modular Setting

OneBuild Modular Setting

The state and county funders thought the project was very innovative and awarded the project funding on the first round, which was quite an accomplishment in such a competitive environment.  And while construction for sitework will commence immediately, the L&I approval process [2] for the modules is just starting with the selected manufacturer which means that modules cannot begin production for at least 2-3 months. 


The design of the project started off with a strong understanding of the shipping constraints [3].  While modular construction can accommodate wide open and double height spaces, the greatest economy can be achieved when modules are essentially intact, self-contained boxes.  Given the tight construction budget, we elected to be conservative with our first project and go the latter route, expressing the modularity of the construction type in both the unit planning and exterior expression.  Intent on a design that would allow the new homes to fit in with the neighboring modest and traditional housing, we looked at the gable form of the archetypal house.  However, the width of the units were 14’ wide and gables over each unit which would have created a busy roofline.  Instead, the gable was split over 2 units and the two halves slid past each other to provide modulation along the street.

 KAT concept diagram

KAT concept diagram

As townhomes, the stacking of units creates a fairly straightforward connection (or marriage) of modules with similarly straightforward wall and floor/ceiling assemblies; however, transition between the floors (namely at the stairs) had to be increased due to the redundant structure in the floor/ceiling assembly which resulted in lower ceiling heights than typically desired. The flats were not limited in ceiling height and the floor/ceiling assembly still posed some challenges relative to the sound transmission and impact noise.  In addition, the marriage line required some attention in the detailing since there were openings between modules.  This was not an issue at all with the Townhomes since the connection between modules was only vertical. However, the marriage line at the stair between upper and lower modules will be carefully reviewed during the “button up” phase [4].

Many owners assume incorrectly that modular inherently means a savings in construction cost.  As one modular vendor aptly described, modular construction uses the same lumber and drywall that a site –built project requires. The deliveries that occur to a job site still take place, just at a factory leading to basic materials costs which are more or less the same as traditional site-built construction.  It is true that the working conditions in a factory are much more efficient and result in lower material spoilage and waste, yet any cost savings in labor are offset by the fact that the modules are over-engineered to withstand the structural impacts of transport and lifting by crane. In fact, there is almost double the wood framing in a modular construction project than typical site-built project, making the modules very structurally robust. So it is not feasible that the costs would be less. Now if there were some economies of scale (not as significant on an 18-unit project), there is the possibility for the overall cost per square foot of the modules to come down significantly.  

Where the potential cost savings lie are in the construction interest carry. For any developer of affordable housing, the ability to reduce the amount of interest paid means that there are more funds available for higher quality, durable finishes or a play structure for the children who will live in the project, or the staff time to provide supportive services for the residents.

2013_0315 Modular Graphic-2.jpg

Shorter construction time also means that the units are available for residents to move in sooner meaning the owner can start collecting rents and servicing the debt faster.  This is of benefit to any multifamily developer, non-profit or market rate.  However, for the affordable housing developers, the ability to provide more units in a shorter timeline means that they have the ability to serve more hard-working families, seniors, and veterans in need of housing.

We look forward to seeing whether Schemata’s first modular construction project will be the tipping point for the affordable housing industry and for Schemata’s multifamily portfolio.

  1. Housing Washington is the state’s affordable housing conference.  It is held annually and between 700-800 people attend - primarily non-profit housing developers, public housing authorities, social service providers, lenders, attorneys, architects and contractors working in the affordable housing industry.  As one of the largest of its kind, the conference draws 10% of the attendees from other parts of the country.
  2. Washington State Labor & Industries will review the modular plans for adherence to building and energy codes.  L&I will issue a Gold Insignia for each module, which will dramatically decrease the permitting costs but will increase the costs for special inspections.
  3. Trucking dimensions are roughly 14’ wide, 65’ long and 14’ tall.  Modules can be wider or longer, but pilot cars will be required, adding to the already high transportation costs. 
  4.  Button up refers to the patching of the marriage line between modules – both vertically in the townhouse stair and horizontally between rooms of the flats.

Rail-Volution 2012 -- It's (almost) All About the Bike

Rail-Volution is a national transit -- and by default -- urban livability conference that was conceived in Portland, Oregon during the 1990s. Initially focused on transit and how transit can lead to more compact and sustainable development, Rail-Volution has expanded into what must be one of the most diverse urban livability get-togethers in the nation. And naturally, bicycle transportation is figuring more prominently every year. A cycling enthusiast myself, I seized the opportunity to join two (of at least four or five) mobile workshops centered on bicycle transit, and its current and future prospects in Southern California.

The first tour was in Santa Monica, and featured a taxing ride along the Santa Monica Pier and the beach promenade. Our docents included folks from the city, as well a local bicycle advocacy group -- all who voiced great optimism and support for the integration between bikes and transit both currently and in the future.

Along the Santa Monica beach, the city has built a skills course, pictured above. If you look to the upper right of the image, you can see painted lines, replicating those one would ordinarily find riding on the street, but presented here in safe, car-free environment where beginning cyclists can comfortably practice the skills required to ride in traffic. The skills course, which was several hundred yards long and maybe a dozen wide, also had cones and painted, maze-like lines, where one could test and improve one’s stopping and handling abilities. Our docents told as that the skills course was requested by the community, and has been a huge success with those who have utilized it saying that it gave them the courage to ride in traffic, and ultimately leading to a significant increase in new bike commuters. What a brilliant idea.

The well-organized tour also included other infrastructure enhancements that not only encourage cycling, but achieve other sustainable goals Santa Monica has. Pictured above is what we were told was the world's (well, at least California’s) first living street. Features included a woonerf styled profile, where all uses -- including pedestrians, cars, and bikes, share the same, curb-less plane. Parking was over sand set- porous pavers, and the asphalt itself was porous. The three block, formally crime ridden street was built a few years back, and since its completion has been a centerpiece of the neighborhood's revitalization. A particularly nifty feature were the solar-powered street lamps, shown below surrounded by native, drought tolerant plantings that help treat road run-off using with phytoremediation. Also note the typical street signs whose dignity is raise at least a notch or two by steel frames, painted to match the street lights.

And (I suppose) what would be a sustainability-themed bike tour without a farmer’s market. Indeed. The group enjoyed a great lunch at Santa Monica's, which had bike parking for what seemed to be hundreds of bicycles; a welcoming sign, to be sure.

Our tour concluded at the Santa Monica Bike Center in the heart of downtown. A private enterprise, the Center rents bikes and sells bike schwag. Germane to our tour, the Bike Center also has a subscription-based bicycle storage facility, showers, and locker rooms. In the near future, they plan on also being a bike-share location. A great combination of services as well as a model for other aspiring communities, as the profits from the bike rentals offset the lack of profits from the bike storage and showers, allowing for the assemblage to actually turn a profit and have the proprietors not only consider an expanding, but to open other locations as well. Just look as those sexy Saris double-decker racks in the storage room.

Another day found me on a bike tour of downtown Los Angeles. Contrary to popular opinion (including my own), downtown has a rapidly emerging downtown scene, with an intensity and density that was surprising and sure to match or even exceed my beloved Seattle's in only a short time. And it is not only about the new; in fact, what impressed me most about downtown LA (which is where I stayed for the conference, instead of at the conference hotel in Hollywood), was the legacy of outstanding buildings be they 50, 60, or even 100 years old; so much for the myth of LA being only a post-war, automobile oriented city. Give it a decade or so, and LA will be one of our nation’s hippest down-towns to live in. Please allow me to digress a bit, and share a few images of some pre-war, pre-freeway images of downtown that I had a chance to take prior to the conference, that merely hint at downtown’s urbanity.

Especially rewarding were to explore were the many pre-war office building lobbies, the design and materiality of which speak to Los Angles’ industrial and corporate might during the early 20th century (and to this day). I absolutely love the profile of the chemical plant above the entry doors to the former Standard Oil (Exxon, in today's parlance) lobby, which has been repurposed into the tres hip Standard Hotel.

End of digression -- back to the bike tour. Though nascent, LA's bike program is off to a robust start, and reflects California's entrepreneurial spirit. On Spring Street, pictured below, one can see one of LA's test, green painted bike lanes. Still in the vetting stage, we rode on several surfaces that LADOT is evaluating for performance. Just look at the width of that lane -- a full 6 feet as I recall. And one would never guess, but there was barely and outcry, or so said the docents, when a parking lane was removed for its creation. Although I don't recall from what low, bike commuting has increased 200% in total numbers and 600% among women since the lanes were debuted.

Discussion along the way included the late 2012 launch of LA's bike share program, which will begin downtown and feature bike frames made of 100% recycled aluminum. As we meandered our way on bike lanes, soon to be bike boulevards, and other such inspired bike infrastructure I could not but think how impressed I was with the speed, social acceptance, and political will required to execute such ambitions in a city as large -- and auto-oriented -- as Los Angles. While it is true that the weather is simply superb for cycling, and the terrain a bit more hospitable on the whole than say Seattle's is, if a city such as Los Angeles can vision and implement a bike program with such speed and alacrity it speaks well to the movement as whole.