HomeZone: Modular housing -- Some assembling required

  • Article by: JIM BUCHTA , Star Tribune
  • Updated: January 31, 2003 - 10:00 PM

Modular homes usually are made up of two to five major units, which are assembled on the permanent site.

Photo: Minnesota Union Builders

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While the winds howled and the temperatures hovered below zero a couple of weeks ago, work crews building townhouses in Hugo were bundled up like Antarctic explorers. But in a huge factory just across the street, carpenters from Minnesota Union Builders were comfortably pounding away on houses in sweatshirts and jeans.

Some were even wearing T-shirts.

They're employees of the state's newest modular housing manufacturer, a unique partnership between private investors and several Minnesota construction trade unions.

At the beginning of November, the company moved into its new 92,000-square-foot production plant on the outskirts of Hugo, about 35 minutes northeast of the Twin Cities.

The contrast in working conditions isn't lost on company Vice President Ron Nyberg, who says building under controlled conditions is not only good for the employees, it makes it easier to manage quality control.


When the plant is in full production, he said, it should be able to produce 350 houses a year more quickly and at slightly lower cost than traditional site-built houses. Each house should take less than 10 days to build vs. 35 to 40 days for a site-built house. Prices now range from $110 to $120 a square foot, not including the cost of the lot, comparable to site-built homes. As the process is refined, prices should fall, said President Jim Boo.

Technically, the primary difference between a modular house and a site-built house is pretty simple. Modular houses are built in a factory in two to five major pieces then shipped to a job site, where the parts are picked up by a crane, set on a prepared foundation and attached to one another. Sometimes crews build the garage and other elements on site.

While modular houses are manufactured, they're different from what's known as "manufactured" houses -- also called trailers or mobile homes -- which usually are delivered in one piece with wheels attached. Modular houses are delivered to a building site on huge expandable cargo trailers.

In addition, modular houses must be built to the same state and local building codes as site-built homes. Manufactured houses are built under a different code, a standard called the Federal Construction Safety Standard. A manufactured home is built on a non-removable steel chassis, and there are restrictions on where they can be placed. That's not the case with modular houses.

An 'execution' process

Inside the cavernous factory, there are 18 work stations lined up in a row. Each is equipped to handle a particular function, starting with floor assembly and moving through walls, plumbing, painting, cabinets, roofing, doors, etc. As each module moves down the assembly line, another one queues up.

At each station, workers -- including plumbers, electricians and carpenters -- rely on a set of plans that describes exactly where every outlet, wall stud and piece of plumbing needs to be installed. No structural decisions are made on the plant floor; it's simply an "execution" process, Nyberg said.

The company has more than 30 plans customers can choose from, but it also can build custom designs. Crews still are working out the bugs in the system, so the company has yet to produce a completed house. Two prototypes are under construction and will be delivered to customers in Isanti. The homes -- one is a rambler, the other is a Cape Cod -- will be priced at $175,000 and $225,000.

All the materials for each house, including the cabinets, carpet and windows, are custom ordered and delivered to the factory in a just-in-time mode. That means the company doesn't have to store inventory.

As the modules move down the line car-wash style, they are completely assembled. Doors, windows, tubs, toilets and light fixtures are installed. At the end of the line, each module is shrink-wrapped, then makes a left turn into a loading area and is lifted onto a low flat-bed truck that carries it to its destination.

Growing interest

So far, there's been strong interest in the houses from developers and nonprofit neighborhood groups such as East Side Neighborhood Development Co. in St. Paul, which is considering modular houses for some in-fill sites.

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