Posts Tagged ‘custom home’

Prefabricated Housing is an Appealing Engineering Problem

November 27, 2010

Recent “musings” about architecture with another engineer who is a good friend prompted me to make this observation:

Utility in a building comes from a certain sense of “object-orientedness” not unlike good software.

“What?” he exclaimed. “NO – great architecture comes from symmetries, asymmetries, materials, and and an artful sense of fancy or awe…” We are talking about two very different design objectives: usefulness and sensual appeal. At the end of the day, it is both of these that make great design.  Not being an architect, I have to confess that I don’t know just what makes great architecture. On to the problem of design…

Before I could get to ponder the question of great design very far, another friend asked me to do some research on prefab housing. His Objective:

Move to the countryside and retire in an ultra-modern 3500 sq-ft “green” home that costs no more than $100,000 complete with solar/wind power systems, appliances  and furnishing – he provides the land that is already in hand in the middle of nowhere with no utility infrastructure nearby (none whatsoever).

A FANTASY…  But for a bigger budget I wonder what he can buy. I think he can do it for $350,000 ($100/sq-ft) – he has a few builders to choose from, but who knows if what they will actually finish will satisfy my friend… I think I could do it for $200,000 today for materials and construction labor and a year to engineer the house and have it built (no fee for me in that number)… And with economies of scale, perhaps I could build the house for a good bit less than that! I may be surprised, however, at how much the power system will cost – maybe I am way low on my own estimate…

This prefab house needs to be (my friend is talking):

  • Affordable – like a mobile home,
  • Durable – like a rail shipping container,
  • Energy-efficient and completely solar/wind powered,
  • Free of toxins, contaminants or hazardous materials, with recycled or repurposed materials used wherever possible.
  • LEED Bronze – or even Gold certified!

After some more conversation, further details and expectations began to emerge:

  • Built on site by no more than two people,
  • Compact and spacious – how those both come about, I can’t quite imagine as we are talking, but that is the “art of design”…,
  • Modern and visually appealing,
  • Reconfigurable.

How prefab? One big piece delivered to site, or 10 pieces or 100 or 1,000 or 10,000? His answer: 1,000 pieces plus the “nuts and bolts” would be OK – certainly not much more than that. And tools? Just hand tools, a power drill, a small power generator, and a hoist of some sort to lift panels into place and complete the structure… Here is what he expected to receive on site – initially, just the “structural system”:

  • A foundation plan for cement piers and synthetic cement or steel floor beams,
  • A skeleton aluminum or steel framework of some kind,
  • Exterior and interior solid wall panels with a standard dimension,
  • Exterior roof panels and interior floor and ceiling panels,
  • Exterior wall panels with a variety of windows installed,
  • Exterior and interior doorway panels and doors.

The structural system needs to be engineered. I’m thinking, “These are a lot like software objects. They have “attributes”, and some “inherit” attributes from others. Some of these objects have “behaviors”, and there are “interfaces” between objects.

What about “infrastructures”? He didn’t think about that…

  • Electrical interconnects, plumbing junctions and airflow ducting between panels,
  • Electrical runs, plumbing runs and airflow ducting across panels,
  • Power system, environmental system, water system and sewage system with options for external tie-ins to conventional utilities.

These systems also need to be “engineered”. So, this is like “peeling an onion” – good “sport” for an engineer!

What about “finishing touches”? “Oh yeah,” he says, “that, too…”

  • Floor coverings, wall coverings and exterior veneers,
  • Door fixtures, kitchen fixtures, bathroom fixtures, utility room fixtures and light fixtures.

All “green” – they need to be specified and selected. What about fasteners? “Hand-tools and a power drill, only.” he reminds me. Fasteners are a big industry – they are integral components of the home that must be engineered into every part. More systems engineering! LEED Gold certified? OK – maybe…

What else?

  • “Super-efficient” appliances,
  • “Green” furnishings,
  • “Hi-tech” entertainment, communication and computing equipment that is integrated, efficient and survivable with interfaces to the outside world from remote locations,
  • A total-home control system.

Even more systems engineering. I am almost drooling over the challenge of doing this. This might be a really fun problem to solve – a fun company to start!

  • Design the home on-line in an evening with a web-based 3D visualization application,
  • Order all materials, systems, appliances and even furnishings on-line,
  • Pay by wire-transfer the next day and finance any remainder necessary also on-line,
  • Contract the foundation to be done the day after financing is secured and payments are received,
  • Receive all materials in secure, returnable rail containers on site in a week by specialized shippers – maybe even by UPS,
  • Complete the home with your significant other in another week, or have the home assembled in that timeframe as an ordered service,
  • Move-in two weeks after the order with the critical systems completed,
  • Completely finished the house in less than a month.

I think that there is a lot of good to be done in this business area. I think a new prefabricated, modern, green, energy efficient home can be built for the buyer for less than $50/sq-ft for materials and construction labor plus the land and supplementary power system if the scale of business is sufficiently high and the systems engineering is thorough enough to capture the nuances of a LEED-certified home’s design and construction requirements. It may well be the wave of the future for new home construction. I see lots of companies trying to enter this market, but I don’t see any that have comprehensively engineered designs and green systems that would satisfy my friend – certainly not for what my friend can afford to spend. He’s still looking, and I am now thinking…

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