DIY Network

Building Off-Site From "Best Built Home" episode DBBH-101F

Can you imagine building a home in a factory? Well, in this segment a builder in Virginia (Pulte) does just that. They have created Pulte Home Sciences (PHS) (a division of the company) to develop a manufacturing process that makes building more precise, efficient and higher in quality.

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	The Lopez family in Virginia live in a Pulte home.
	Figure A

The shell of a Pulte house is built in a factory environment much like that of a car manufacturing plant. This enables Pulte to build a home without the delays caused by weather or temperature changes. The foundation walls, insulated exterior walls with the windows pre-set and flashed, floor truss systems, and steel stud interior walls are all made in an environmentally controlled factory setting (figure A) then sent on flat bed trucks to the construction site. The plant can manufacture one house every four hours and on-site assembly takes weeks off the building schedule. It's like a giant puzzle being assembled right before your eyes.

"Everything was essentially a big puzzle when they brought it to the site," Tom Lopez, who lives in a Pulte home, said. "And to me that really optimized the efficiency -- not only in the construction process but in the quality once the product was assembled."

The advantages of factory-built homes include:

• Premium materials are used.

• All the components are produced under an environmentally controlled setting, as mentioned above.

• Can build in "all" seasons no matter what the weather is doing outside.

• Every piece of the home shell is built in a matter of hours. In fact, it takes about four hours to build a house in a factory.

	Figure B
	Figure C
	Figure D
	Figure E
	Figure F
	Figure G

Following is Web Extra content on how the Structural Insulated Panel (SIP) system works:

Structural Insulated Panel (SIP) Wall Assembly

• Overall quality is improved by delivering walls that are built under controlled conditions (figure B) resulting in straighter walls inside and out.

• The SIP wall system is stronger than conventional 2 x 6 framed walls in every category (axial, bending, racking and shear tests).

• SIP walls (figure C) provide better energy efficiency by delivering a whole wall R-14 rating and allow for a tighter envelope with less air filtration.

• Building wall panels up to 36' in length reduces field construction time.

SIP Lamination

• SIP blank panels are fabricated by laminating an EPS foam core between two sheets of 7/16" thick Oriented Strand Board (OSB) 24' in length. The SIP composite is then placed under pressure (figure D) while the adhesive cures. After lamination, the SIP blank is tagged for cutting -- using specialized material handling equipment.

CNC Machine

• The cutting operation is performed by a state-of-the-art CNC machine, precisely cutting and routing (figure E) each section of SIP wall via a cut routine derived directly from the engineering drawings. This provides a high quality wall component built to tighter tolerances than can be economically achieved utilizing conventional "stick" framing techniques.

Sub-Component Assembly

• A computer controlled framing table is utilized to frame window and door assemblies. Pneumatically powered brackets clamp the dimensional lumber in the correct position for assembly while SIP sections are attached to complete the component. The entire assembly is then flipped by the machine allowing the opposite side to be nailed together.

Framing

• Sub-components and larger wall sections are mated together on the framing tables. Mechanical clamps aid in the assembly ensuring a tight fit of all wall components. Lifting straps are installed, house wrap is applied and the wall section is now framed.

Window Installation

• A precise and repeatable window installation procedure (figure F) in a controlled environment provides a high level of quality control. Plant installed windows also reduce assembly time in the field.

After the factory work is done the field-assembly process begins. The delivery to the site by the trucks is sequenced to match the erection order of the house. First, foundation walls (figure G) are delivered, followed by floor decks, the SIP and steel walls and finally the roof trusses. Overall, the home-production cycle is reduced by approximately 20 days as compared to traditional construction!

In the next segment host Lynda Lyday will visit the building science laboratory of Build IQ and meet with CEO Michael Dickens to discuss the concept of the integrated approach to home building.

RESOURCES :

Oakwood Homes
Phone: 303-486-8500
Website: www.MoreHouseLessMoney.com

Hedgewood Properties
E-mail: sales@hedgewoodhomes.com
Website: www.hedgewoodhomes.com

EarthCraft House™

EarthCraft House is a voluntary green building program of the Greater Atlanta Home Builders Association that serves as a blueprint for healthy, comfortable homes that reduce utility bills and protect the environment. The aim of the program is to help Atlanta's home builders be leaders in smart growth management and environmental stewardship.

Website: www.earthcrafthouse.com

Pulte Homes
Toll-free: 800-777-8583
Website: www.pulte.com

GUESTS :

Paul Kreischer
Energy Efficiency and Comfort Consultant
Lightly Treading
Phone: 303-733-3078
Website: www.lightlytreading.com

Rob Johnson
Energy Efficiency Consultant
EarthCraft House
Website: www.earthcrafthouse.com

Michael Dickens
CEO, BuildIQ
Website: www.buildiq.com