Home Building - Traditional vs/ Modular

Photo credit: haammss.com Thinking of building a new home or have you recently been to a new neighborhood under development?  I recently visited some friends who bought a new house in one of these new neighborhood developments and the first words out of my mouth were, every house looks the same.  If it wasn’t for the numbers on the house we probably would have been driving around in circles trying to figure out which house was theirs.  In most major metropolitan areas it seems that every new neighborhood development has the same characteristics and same method of build, same design, relatively same cost and same market of buyers. Then you go to a development of individual lot sales. A developer is selling off blocks of land giving the buyer an opportunity to build a home they desire so long as it fits within a certain style or with a number of pre-authorized builders.  With these developments you get a little flair, some diversity in design and you see a market that is a little more unique but cautious in their style of home build. Then finally you have the individual lot or land purchaser.  This is someone who has a dream to build a home of the style they have always wanted.  An individual purchase of a lot using whichever builder they desire and in a creation that truly sets them apart from their neighbors. For more than three quarters of the population in North America, the people looking to build a home use the traditional method of building a home.  Buy the lot, level it, dig out an area for a foundation, build the foundation and slowly build your house one 2x6 at a time, followed by one sheet of plywood at a time, followed by one wall at a time and 6-12 months later, you have a house.  Well, hopefully you have a house, along the way you experienced worker shortages, trades setbacks, cost overruns, upgrades, worksite theft, cutting corners, crazy weather and rain checks of interior materials.  Whoever said building a house was an easy task clearly never built a home in this traditional method of stick and frame. So why do we build houses this way?  Well for one, developers who build an entire neighborhood of houses that look the same, have calculated the cost to build right down to a fraction of a penny and have built their building models around these costs.  They have also purchased land where every lot is cleared and leveled to make the building process simple.  Then, they employ the traditional stick and frame build method, a slow process that allows people passing by to slowly see the progress of a new community being built. So is this the best method for building a house? Over the last 30 years a handful of builders with an idea to design and build a house faster than conventional methods has taken up a quarter of the building market.  We have seen the introduction of modular or SIP (Structural Insulated Panel) homes being built in factory in full, then disassembled and transported via container to a build site where the use of a long boom crane can place each and every completed wall and roof truss into place and the house is built in as little as 6 days to a couple of weeks.  There are many manufacturers who employ this build method and each one of them integrates into their design components reductions in cost that improve the systematic build of the house.  There is a considerable reduction in waste of materials while improving the time to build.  Every component of a wall is already built into place, electrical, plumbing, insulation, interior/exterior walls, siding, roofing and interior finishes.  Additional enhancements allow for solar panels, infrared heat panels and radiant in floor heating.  Savings for this method can reduce your standard home build price by up to 50% depending on your market. For myself, as an Architectural Draftsman, I steer my clients towards the SIP (Structural Insulated Panel) build method.  The reasons are simple, far less expensive, energy savings from 50-70%, build time reduced to a week or two, all internal electrical and plumbing conduits are built in, insulation is airtight and greatly eliminates moisture buildup while greatly improving soundproofing and you can design your house however you choose, the factory is adaptable to your needs. Here are some interesting conclusions on a Traditional vs Modular (SIP) study done in 2006 conducted by RS Means Business Solutions: The RS Means Business Solutions team concluded that not only does using prefabricated SIPs save significant time on site, it reduces labor costs. In addition, rough-in wiring with prefabricated wire chases further increases these savings. Although life cycle costs were not part of this study, it should be noted that SIPs installed to meet Energy Star requirements offer significant savings in energy use. A typical 2’ x 6’ wall with fiberglass batt insulation has an R value of 19 while the comparable SIPs wall is rated at R 22.3. In addition to the higher R values, the sealed joints between the SIPs reduce air leakage (drafts) and energy loss. Energy efficiency is a very attractive selling point with many potential buyers, despite the higher material costs of SIPs, because they minimize heat loss/gain in a new home, increase comfort, and save money in the long run. BASF may wish to evaluate labor and materials differences between equivalent wall configurations (i.e. a 2 x 4 wall compared to a nominal 4 inch SIP wall.) Similarly, an R-19 SIPs wall could be compared to a “high performance” 2 x 6 conventionally framed wall. To review the study in its entirety, click on this link:  http://www.sips.org/downloads/rsmeanssipscoststudyreportjan2007.pdf The following is a comparison we like to use when demonstrating to our clients the differences in building methods.

	Traditional 2x6 R19	Modular (SIP)
Energy Efficiency	Baseline	48% More energy efficient
Fire Resistance	Sticks require one layer of 5/8" drywall to meet an hourly wall.	A one hour fire wall is achieved with a minimum 2 layers of 5/8" drywall each side of the wall. 4 layers on each side will achieve a 2 hour wall.
R Value	The Department of Energy's Oak Ridge National Laboratory has studied and tested the performance of entire wall assemblies in large sections. The resulting whole-wall R-value data reveals that a 4.5" SIP wall rated at R-14 outperformed a 2"x6" wall with R-19 fiberglass insulation.	SIPs R-Value: 4" wall 15.0 – 16.0 R-Value 6" wall 23.0 – 24.0 R-Value 8" wall 30.0 – 31.0 R-Value 10" wall 38.0 – 39.0 R-Value 12" wall 46.0 – 47.0 R-Value
Strength	Baseline	20-30% Stronger – The structural characteristics of SIPs are similar to that of a steel I-Beam. The OSB skins act as the flange of the I-beam, while the rigid foam core provides the web. This design gives SIPs an advantage at handling in plane compressive loads.
Seismic	Yes, tie downs and additional material/ labour costs required	Yes, additional tie downs may be required depending on design methods
Waste Created	Baseline	30% less salvageable structural lumber sent to landfills over stick. The EPA estimates that every year we send to landfills a BILLION board feet of "salvageable, structural" lumber. Enough to build more than 62,000 average size new American homes. PBS SIPs are also recyclable and made with a significant amount of recycled content.
Labour Costs	Baseline	Up to 55% labour savings.
Indoor Air Quality	Baseline	The tightness of the SIP building envelope prevents air from gaining access to the interior of the home except in controlled amounts. A controlled indoor environment is both healthy and comfortable. Humidity can be controlled more easily in a SIP home resulting in a home that is more comfortable for occupants and less prone to mold growth and dust mites. The EPA says that 19% of all American households have at least one member with asthma. They go on to say that four out of ten (40%) of children born in America today will develop some type of respiratory ailment. SIPs build healthier homes and buildings.

  As a final word it should be noted that myself nor my business represents any builder over another.  3D Cube Design employs its own building method which is licensed out to interested builders.  We also provide the free tools to anyone who wants to design their own home and take that design to whichever builder they feel best meets their needs, budget and style of build.  If you are in the market to build a home using the Modular or SIP system, email us and we can provide you the name(s) of SIP builders in your area. Our next article will feature the cost breakdowns of a traditional stick and frame home build.  We will provide an excellent online tool which allows you to factor in all the components of building your next house in your market and we will use this tool in 3 different markets to give you an idea of just how expensive or inexpensive building a home can be in today’s market. Ian Phyper is the  President of 3D Cube Design and can be reached at [email protected] http://3dcubedesign.com/