After a community has been designed and floor plans for the homes have been produced, it's time to start building the model homes. The steps taken to construct these homes mirror those for each new home purchased by a future homeowner.
The first step in constructing a new home is installing the sewer system — typically with reinforcing steel — below what will become the concrete slab foundation of the house, according to Trevor Barger, an urban planner who founded a development assistance firm called Espiritu Loci (translated, “the spirit of the place”) in Scottsdale. The cement is then poured early in the morning and takes about a week to dry and harden.
Creating the 'building box'
The next step is creating what's known as the 'building box' and include framing, typically with wood. “The building box includes tresses for the roof,” Barger said. Then the roof sheathing (consisting of large panels of wood) is installed, he said. The floor structure (not the floor finish yet, but what is underneath) also is installed.
Plumbing, HVAC and electrical
“It’s at this point in the process that everything hidden goes in,” Barger noted, including sewer lines and
water supply lines for each fixture. It’s also at this time that bathtubs are installed because there’s more room to maneuver large heavy objects.
Heating, ventilation and air conditioning (HVAC) ducts are installed, followed by plumbing and electrical infrastructure, said Hal Looney, Arizona president of Shea Homes’ Active Lifestyle Communities.
“The HVAC contractors work with our construction document architects to coordinate mechanical unit locations in the attics, desired SEER values and to ensure optimum air conditioning and heating supply
and return vent locations so we balance and maintain symmetry in the primary spaces of the home,”
said Steve Berry, senior vice president of architecture and design for Robson Communities.
Heating, ventilation/air conditioning ducts and plumbing typically are installed before electrical wiring, Barger said, because it’s simpler to run wiring around pipes and vents than to try to install pipes and ducts around a maze of wires. An electrician installs receptacles for lights, switches and outlets and runs
wires between the breaker panel and each receptacle in addition to installing wiring for telephones, internet, cable TV and music systems.
Doors, windows, insulation and drywall
As these hidden elements are finishing, exterior doors and windows are installed to “seal the box” before the insulation and protective exterior material are added to keep these elements dry, Barger said. The insulation is typically one of three types: fiberglass (which looks like pink cotton candy), cellulose (made from recycled paper) or liquid spray-foam.
The exterior framed walls are covered with insulated panels which can look like blue bright colored or reflective foamboards, Barger said. Then a plastic sheet or vapor barrier is applied over a wire mesh
to hold the stucco to the wall, he said.
The roof is loaded with the roofing finishing materials, usually in bundles to add weight to the structure so the walls don’t crack when the weight of a heavy roof is added later. Interior drywall — plasterboard, wallboard or gypsum board — is applied next, Barger said.
Interior finishes and exterior last steps
For the next three months or so, Berger said, the interior finished are installed. These include the cabinetry, countertops, flooring, electrical fixtures, plumbing fixtures, interior doors, kitchen appliances and interior paint.
Then the roof tiles are installed. Primer paint on the exterior of the house is next followed by the exterior finish — usually stucco, stone or brick. Next, the top coat of exterior paint is applied.
Cement is poured for exterior walkways and the last part of the home itself that’s added is often the driveway, Barger said, explaining that the driveway is poured after all of the trades have finished their respective jobs “because you don’t want a truck parking on a newly poured driveway and potentially cracking it or leaving marks.”
Landscaping is the very last thing that’s added to the home-site, Barger said. Voilà — it’s almost time to move in.