Pre-manufactured home

[eman7911]

I'm in the market for a new home and I came across an area of new construction. The homes are large (approx. 2400 sq ft) and all brick. The builder in this area has a selection of models to choose from. The question I have is the type of construction he is using. His homes are pre-manufactured. All the walls arrive on flatbed truck. They are lifted into place and screwed to the slab then joined together to form the frame of the house. The roof is an engineered truss that arrives also on flatbed. The trusses are lifted by cranes to form the roof. When the homes are completed, they look just like any other home in the area. How does this type of construction (pre-manufactured) differ from "stick built" construction ? Is the structural integrity of a pre-manufactured home equal to stick construction. I've found the cost of construction for pre-manufactured considerably less than stick construction, probably because there is less wood used. Can I get some opinions on this before I sign any contracts ? Thanks

[majakdragon]

I am not qualified to say one is better than the other. The cost is lower due to mass production, not use of less wood. I worked on a Hotel up North and all the plumbing was pre-fabbed. All the main drains were pre-measured and cut/glued in the shop. This was multiplied 16 times and it cut the cost considerably. It's what happens when it is installed that counts.

[Doug Aleshire]

eman7911,

Before I answer this, we need to understand some terms, as they are important to whoever reads this. Many times the words mean different things to different folks.

The term “Manufactured Home” is both generic and specific. In the specific sense it refers to homes built to the HUD code. **These homes have a non-returnable carrier (steel frame) attached to the home.** They may use building products specific to the HUD code and recreational vehicle market. They are typically not designed to be put on a basement without re-engineering the frame. Prior to 1974 they were called mobile homes.

Modular homes do not have a steel frame and are built to state building codes using the same building products available to a stick builder. A quality modular structure is typically stronger than a site built home because it has to withstand the rigors of travel.

With a modular home you get efficiency and quality control. Efficiency begins with modern factory assembly line techniques. Your home travels to workstations, with all the building trades represented. Work is never delayed by weather, subcontractor no-shows or missing material. Quality engineering and modular construction techniques significantly increase the energy efficiency of your modular home. A quality control process provides 100% assurance that your home has been inspected for code compliance and workmanship. So when you asked about the reason for cost differences, we are dealing with mass production under controlled conditions. Better production time means lower costs yet the quality of the materials is no different. I’ve been through one plant and was amazed at how fast they are made!

Manufactured or double wides are built to less stringent HUD codes. This metal frame is part of the construction, they carry a title (like a car) and they will depreciate in value over time.

Modular homes are constructed using the same building codes as on-site "stick built" homes (because they are stick built). These codes generally include the UBS, NEC, UPC and UMC. Modular homes carry a certificate of occupancy and a state seal, and will appreciate in value the same as the local market will for site-built homes. People are sometimes confused when they see a modular home being transported (like a manufactured or double wide); they're transported this way because they're built in a controlled, indoor environment and are delivered in as many modules (pieces) as necessary to complete the house.

Many communities have restrictions on where manufactured homes can be located. This is due to the fact that they are on a metal frame and if they are placed on a site, municipalities cannot acquire the taxes on them. They are considered “temporary sites”. Modular and site-built homes on the other hand, are constructed to the same building code required by your state, county and specific locality and therefore are not restricted by building or zoning regulations. Your new modular home is inspected at the assembly plant during each phase of construction. Evidence of this inspection is normally shown by the application of a State or inspection agency label of approval.
Modular homes are appraised the same as on-site stick built homes, using site-built comparables. This is a big difference to that of manufactured home that almost always decreases in value. So when it comes to financing, banks and insurance companies view modular homes as a site-built home.

I would discuss your issues with your banker, insurance agent and your local building official for any feedback. This should help you in your final decision.

Hope this helps!

[eman7911]

Thanks Doug and Majakdragon for the replies. I don't believe these homes I'm talking about fit into either the manufactured or modular category. These homes don't arrive fully assembled on a flatbed. Rather, just the framing arrives pre-assembled. The wall frames are lifted by the construction crew into place, nailed together and bolted to the slab. The electrical, plumbing and sheetrock are put in just as any other home. Really, after the framing is up, the house is constructed just like any other home. I guess my concern is the truss roof being used on these homes(trusses are not common down here in Louisiana) and my other concern is that the studs in the home are 24" on center, not 16" on center like most stick construction. I hope this helps explain things more.

[Doug Aleshire]

eman7911,

Are we talking about about a Wausau home type? What is the companies name that this is coming from? What you describe is a "modular" home, manufactured in a factory and brought out to the sight. This appears to be tht of what Wausa puts out. I grew up in Minnesota and this type of home is sound construction. Years ago, it was considered an insult when you have construction companies around to stick build it for you. The nice thing about them was it took shorter time to get them up and be habitable. Cost wise was another issue. In one sense they were almost as much as a new home, as time goes by and methods to increase the production, they have come down in price.

2' O.C. wall studs would not be bad if we are talking about 2x6 walls and the drywall is 5/8". It doesn't take much to make 1/2" rock bow in!

Trusses are used allot and I have used them for over 35 years - great time saver! Stronger than most stick built rafter systems.

[Joe.Carrick]

The system you described is properly called PreFab. The components are prefabricated at a variety of suppliers plants. The advantage of this is consistency and cost savings. In almost all cases, such prefab components are superior to on site construction. In some cases the walls and even Floors and Roofs can be constructed using SIP's (Structural Insulated Panels), resulting in greated strength, better insulation, lower cost and greatly reduced construction time.

My opinion is that the homes you describe are far superior in all ways to a conventional stick-by-stick built home of the same cost.

Modular, Mobile and Manufactured all basically refer to the same concept - build the entire home in a factory and then truck it to the site and install it. Usually these are made up of 12' wide sections. The fact that they have to be designed to take the rigors of travel do not make them any stronger and in many cases mean that the materials are lighter and not really as good as conventional or Prefab homes.

[Joe.Carrick]

BTW, I'm not particularly fond of the idea that the studs are 24" o.c., but if the walls are all sheathed with plywood or osb then it is OK. Probably the trusses are located directly over the studs in the exterior walls, and that's good.

I think you said that the exterior walls were brick - solid or veneer ? Using 24" stud spacing for non-bearing walls is pefectly acceptable.

[eman7911]

Thanks Joe and Doug for the additional replies. The builder is JBL Homes. I believe they are based in Alabama. The brick used is solid brick (Acme Brick). Thanks for clarifying that these are called "pre-fab" homes. It's almost as if the builder considers this a dirty word. I asked the builder if he would stick build a home rather than buiding it with pre-fab materials. He said he would, but would charge an additional $3000.

[Doug Aleshire]

eman7911,

If he were to stick build it for an additional $3,000 more and build it the right way, go for it! My personal opinion only.

Good Luck!

[Joe.Carrick]

Hi eman,

When I asked if the brick walls were solid, I meant the following"

Are the brick walls built before or after the house is built? If not, then it's considered veneer regardless of how thick the brick is. IOW, do the exterior brick walls support the roof or are the just applied onto the outside of the walls.

I disagree with doug about conventional stick building vs prefab. The quality control afforded by prefab makes for a better finished product in the long run. These components are engineered and inevitably are better fastened and straighter and squarer than those assembled in the field. You would not want a sheet of plywood to be assembled on site from 1/6" sheets of wood because the quality controls in the factory make a better product. The same principal applies to wall prefab wall panels and trusses.

Ask the builder (JBL is a well known name) if you can visit the truss plant and the prefab wall plant, etc. If they are close enough for you to visit you will get a good education.

[Joe.Carrick]

Yes, some people don't like that word. It was first coined back in the 1950's when Levitt-Town was built in New York.

Probably a more acceptable terminology would be:

"Pre-manufactured Components"

Another great example of this concept is kitchen cabinets. Originally, almost all cabinets were build on site by a finish carpenter. Then the concept of Cabinet Shops started to be used and now we have Cabinet Manufacturers that make cabinets and prefinish them in large plants and ship to anyplace in the country. The quality of the cabinets has improved drastically in just the past 10, 20, and 30 years.

BTW, now the Cabinet Manufacturers are starting to buy their parts from specialists that cut, rout and drill everything on computer controlled machinery. Some of the larger manufacturers have their own machinery, but with the specialists who make doors now getting into making all parts, a smaller shop can produce the same quality by outsourcing this work.

[Pendragon]

Just some other notes on the subject..

A mobile home and manufactured home are the same thing, there is no code difference between them. "Manufactured Home" is a term the industry come up with and adopted for marketing purposes. Built before 1974, these types of homes were not subject to any regulations. In 1974, the HUD code was developed which increased the general quality and consistency of build.
Homes built to the HUD code have a benefit no other home does, State Enforcement. If your HUD home develops a problem, the State gets involved in correcting it. If your site built home has a problem, you're off to civil court to hope for a solution. Mobile homes may or may not have a title and be required to purchase tags every year, depends on the area, the land it's on and other factors. A HUD label is affixed somewhere in the home.

A modular home is a home that is built in a factory and delivered on site in any number of pieces by any method. Modular homes are built to state and local codes, and can be left on the transport device or detached and craned over to a permanent foundation, depending on location. Georgia for example, requires all Modulars to be 'off frame'. These homes are generally recognizable in their pieces before being assembled. Modulars do not come with a title, but rather come with a certificate of origin. A label signifying it as a modular home is affixed somewhere in the home. Depending and where you live will change what the label says. In Florida, it's a DCA label, for Department of Community Affairs.

A PreFab or 'panelized' home is much like it sounds, individual panels are construction in a factory, often with wiring and plumbing already installed and then assembled in the correct fashion on site. These types of homes are always shipped on a flatbed truck of some type. Not sure what type of label these have, probably the same as a modular.

There are advantages and disadvantages to each type.
I'd say the primary advantage of a site built home is that you can see it being built and have some say in the quality of construction. On a factory built home, it's built first, then you see it, any problems with the home then have to be fixed on site, and can be like pulling teeth to get fixed.

The primary advantage of other home types are lower cost, it's been estimated that it would have cost between 40 to 70 thousand dollars MORE to build my home on site rather than as a modular.

Just FWIW, I live in a 2400 sf off frame modular and except for doorways being twice as wide on the marriage wall as the other doorways, it looks like any other site built home and has all the other 'site built' style items like standard outlets and switches, ARC fault breakers for the bedrooms, linked smoked detectors in all rooms, etc. I even had underground utilties done.

Joe: I didn't think anybody built REAL brick homes anymore, all I've ever seen built around here are all veneers. Probably a lost art...

[Joe.Carrick]

Brick homes are still built, but not as much because of cost and the fact that in most areas of the country they are structurally less desireable. The main thing is that if you live in a high Seismic area, masonry is not a good idea because it has to be heavily reinforced. Light construction is much better because it won't tend to be shaken apart - it can move with the land. OTOH, if you live in an area such as coastal New England where high winds are the problem, then weight of structure is an advantage and brick homes are better. Remember the 3 little pigs story?

I don't think you will find many lighthouses built with stick construction and you won't find an mobile or modular homes built with bricks or concrete because it would be almost impossible to transport them.