Our previous issue brought you the collaborative philosophy of the Architect, Interior Designer, Builder and Owner. Each provided their perspective, but it is the builder who must bring the project to life. Pasadera Builders, led by Gabe Garcia, the exclusive builder of the Di Lusso Villas, guides us through the techniques, materials and intricacies of bringing such a project out of the ground, as we watch this hillside enclave evolve.
Rock Solid Foundation
Before design can start, you need to know what you’re designing on. That’s where a geotechnical survey comes into play. Although the majority of the strata within Di Lusso are bedrock, pockets of deep topsoil do exist. Since you don’t know what you can’t see, the entire Di Lusso building site has been tested to determine what the subsurface contains.
Many areas around Texas have expansive soils of clay and/or sandy loam. Expansive soils such as these require different engineering designs because the cycles of weather cause ground swelling and shrinking, which can have an adverse effect on a foundation if the movement is not planned for.
“Our limestone surface and sub-surface provide an excellent environment upon which to lay a foundation. Given the soil conditions, each foundation is engineered to the challenges of the building site,” says Garcia.
Dozers are used to remove loose surface rock then excavation equipment literally cuts through the limestone to level the building site. Foundation forms are then erected to shape and place the slab. Within the foundation forms, the plumbing grounds are placed at all the required drain locations. The plumbing is inspected, making way for the next step in slab construction.
Inspection Note: The County has no regulatory inspection authority, however, Pasadera follows the same inspection processes found in area municipalities.
Once plumbing passes inspection, it’s time to bag. Filling bags with crushed limestone is the equivalent of creating a built-up pad using select fill-in lifts. “Because water can and does seep through crevices and fissures creating under-slab moisture conditions, we’ve employed moisture barriers and drainage that exceeds industry standard. Our goal is not to do enough to get by, but to exceed minimum requirements,” Garcia adds.
Foundation grade beams are embedded into mother earth to create a stable bearing. Reinforcing steel is then installed, tying the entire slab together. This skeleton of steel controls the stress of the foundation during the curing process. The Engineer of Record inspects again and verifies that the design process is executed as intended. With the inspection complete, it’s time to pour concrete.
Foundation note: Since the foundation provides the structure of the villa and not the final exterior finished product, stone “lugs” are dropped down to grade to allow for the exterior veneer (stone) to be applied in lieu of an expanse of concrete normally seen on many foundations.
As the concrete is poured, a vibrator is inserted in the footings to eliminate air pockets to create better compaction of the materials within. This, along with the crew pushing and pulling on the concrete as it’s poured, aids in creating stronger, more consistent material. Anchor bolts are inserted into the concrete prior to the concrete setting. These bolts will be inserted through the wood sole plates of the walls and fastened to create a monolithic structure. Finally, after the concrete sets the foundation is troweled smooth.
Second only to an engineered and well-formed foundation is the framing of the home. Acting as the ‘framework’, the lumber make-up of the walls provides the connection to the slab and the rigidity and support for everything above. “Only the finest hand-selected lumber is used in the construction of our walls – interior and exterior,” says Garcia. “2×6 materials make up the majority of the wall structures.This not only provides superior structural capacity versus 2×4 walls, but also higher Sound Transmission Class (STC) ratings.”
STC is a single-number rating of a material’s or an assembly’s ability to resist airborne sound transfer. In general, a higher STC rating blocks more noise from transmitting through a partition (wall). STC is highly dependent on the construction of the partition. A partition’s STC can be increased by adding mass, increasing or adding air space, or by adding absorptive material within the partition. The latter two components also work in conjunction with increasing the amount of insulation used and provide for a higher R-value.
Framing note: Because we install the electric receptacles in the baseboards, the bottom sole plate is doubled up.
When framing floor systems and roof systems, job-specific engineered trusses are used in lieu of off-the-shelf product. More substantial framing products allow for properly sized and distributed ductwork and insulation packages that make the home more energy efficient.
The use of hurricane ties for the truss/rafters connection to the wall systems gives an added level of security during high wind events. The roof trusses and rafters are topped with radiant barrier decking.
“We’re committed to authenticity,” explains Garcia. “The cornice detail used in Di Lusso is the best of the best.” (The cornice system is all the exposed framing detail at the eave where roof meets wall.) “We use 1×6 tongue and groove soffit, cedar frieze board, fascia board and exposed rafter tails in lieu of standard production home components. Solid wood exterior and interior timbers (beams) are sawn and erected for both structural capacity and architectural accuracy. When you see this system in conjunction with the imported Italian clay roof, you know you have arrived at Di Lusso.”
The roofing system consists of commercial-grade water proofing membrane underneath imported clay tile from the De Checchi family of Italy. The unique color blend of the clay tile exudes the warmth of the Tuscan hillsides, creating an exclusive palette and making the villas one of a kind in the Hill Country. The Anderson divided lite wood doors and windows are installed to complete the water-proofing and make the building envelope watertight.
The mechanical, electrical and plumbing rough-in now begins. With illumination being a key element to the finished product, great time and care is taken to place each fixture. Using efficient low-voltage halogen recess cans brings the correct lighting to the object without highlighting the source. Combine the low voltage system with decorative fixtures and a lighting control system, and you’ll never look at interior spaces the same again.
Once the electrical wiring is complete, the transmission lines for the plumbing and HVAC system are put into place. Mechanical units are paired to deliver maximum efficiency without sacrificing comfort. “The key to air conditioning performance is the removal of heat and humidity, not just blowing cold air. Every bedroom utilizes its own return air in addition to the main return trunk line,” Garcia explains. “Removing and returning the warmer air to the system while adding conditioned air to the same area is the simplest yet most overlooked concept of an HVAC system.”
In addition to ambient temperature, humidity level is the other key component that must be met in order to achieve both comfort and efficiency. By utilizing humidistats to control humidity levels in addition to the ambient temperature, the system will run for longer cycles at lower speeds (efficient). This eliminates the desire to lower the temperature, causing shorter cycles at full speed (inefficient).
The water system is buoyed by a hybrid hot water heater and the full home water filtration unit. A hybrid hot water heater allows for a hot water circulation loop to deliver hot water to each point of use without waiting for all the cold water to be flushed from the system. With this circulation, the hot water unit operates at 98% better efficiency. The water filtration unit provides filtered water to all points of use, benefiting in the removal of harmful elements and thus preserving pipe and fixtures.
Finally, the whole house control system is roughed in. Lighting, HVAC, audio/visual, security and internet access are wired to a central control area. With continuous advancements in technology, the system allows the villa homeowner to stay in control at home, or remotely via smart device.
Upon installation of the mechanical features, all are inspected to make sure they meet building code. With inspection complete, the entire envelope is sealed by wrapping the exterior walls and then filling them with a thermal blanket insulation system (BIBs – Blown-In-Blanket), leaving no voids or thin spots. This efficient and effective system prevents air infiltration/leakage and produces the best value in thermal protection.
You can follow Di Lusso construction progress by reading previous and upcoming editions of Cordillera Ranch Living; by visiting us online at cordilleraranch.com (click on “Villas”); or by contacting us at 888-66-RANCH. Also join us for upcoming open houses to view the many phases of construction. Dates to be announced.