When architects, builders, and manufacturers start a new initiative, challenges happen. At times, those challenges present seemingly contradictory goals. Strength, durability, and resilience appear almost always to conspire against beauty and delight, for instance.
As indoor-outdoor rapport trends as an ever-more-compelling trend in design that new-home buyers demand, for example, builders face brand new engineering riddles around how to create safe, high-performing, durable structures that also allow nature outside the structure become a greater and greater aspect of the resident's living experience.
BUILDER's alliance with Meritage Homes in developing the reNEWable Living Home, by its nature, exposes those challenges, and brings our audience deep into a highly collaborative process--among builders, engineers, architects, and materials manufacturers-- aimed at producing new solutions.
In this instance, the solution is better than the original starting point.
The goal of the reNEWable Living Home is to create a space that speaks to the buyer in terms of sustainability and physical comfort. The cornerless moving glass wall system that would pocket into the wall was one of the ways the team sought to pull those elements together.
According to Paul Knitter, vice president of architecture and product innovation at Meritage Homes, because of buyer demand, these systems are becoming more commonplace in ranch style homes. But when the idea needs to be executed in a two-story structure and combined with the HercuWall system, as is the case with this project, it presents some structural engineering challenges.
The team has already specified the HercuWall system because it offers an airtight envelope with less labor and less product. However, with the HercuWall system, the point loads for the beams were extended beyond what traditional concrete block construction would have been, creating the challenge of figuring out how to cantilever two beams over the 90-degree cornerless, multislide door system.
Knitter says that collaborating on this issue was a small project in and of itself. Because the beam was longer due to the HercuWall system, the team had to find a solution that wasn’t cost prohibitive and still aligned with the premise of the reNEWable Living Home. And, the stars aligned in this instance because the team came up with a solution that solved the issue and became a benefit to the overall project.
BSB Design, the leading architect on the project, worked with Meritage, HercuWall, and Western Windows Systems to find a way to incorporate a 90-degree multislide door system as two pocket doors that reduced the impact of the span and also redistributed the weight to make the door system feasible. BSB modeled the solution in its BIM program for easy reviewing by the entire team.
The model will be available to share with the engineers, who can use the model to run structural integrity tests. Having these models and the engineer involved is critical. As Lonnie Bass, chief plans examiner at Orange County Division of Building Safety, said “It would be up to the engineer of record to design it to be structurally sound. And the door can be installed if it has Florida Product or Miami Dade Product approval.”
But, what does it take to get the product approval? Kathleen Kennan, deputy director of communications, Florida Department of Business and Professional Regulation shared the testing requirements for exterior doors from the 5th Edition (2014) Florida Building Code, Building, which centers on impact resistance, necessary for the high-velocity hurricane prone areas of Florida, like Broward and Dade Counties.
1609.1.2 Protection of openings. In wind-borne debris regions, glazed openings in buildings shall be impact resistant or protected with an impact-resistant covering meeting the requirements of SSTD 12, ANSI/DASMA
SECTION 1626, HIGH-VELOCITY HURRICANE ZONES—IMPACT TESTS FOR WIND-BORNE DEBRIS
1626.1 All parts or systems of a building or structure envelope such as, but not limited to, exterior walls, roof, outside doors, skylights, glazing and glass block shall meet impact test criteria or be protected with an external protection device that meets the impact test criteria. Test procedures to determine resistance to wind-borne debris of wall cladding, outside doors, skylights, glazing, glass block, shutters and any other external protection devices shall be performed in accordance with this section.
Dan Swift, president at BSB Design, says the advanced modeling and the cross-team collaboration solved the support issue in an economically sound way. He says his biggest push back to some of the group’s solutions was that the average consumer couldn’t afford it, which made it then more of a show piece. This was another challenge that the team had solve for during the process, and they were ultimately able to create a way that would be financially feasible for the home buyer.
However, the team wasn’t just solving for the structural impact. With most structural issues, there also is the impact on the interior flow. The team members came up with a solution for a drop beam with ceiling treatments to mask the deflection of the beam, not to carry the load, but to reduce the deflection. They created some tray ceilings in the kitchen to mask the dropped ceiling in the family room, which also helped create a seamless transition. Knitter notes that the design likely will include a few other beams dropped 6” that will be equal to the others and create a unified, coffered look.
Erick Felsch, volume program national accounts manager at Western Windows Systems, points out that during the process, they actually increased the height of the door from 8 feet to 9 feet, 6 inches. This had another powerful impact on creating a more dramatic opening that spans 18 feet. Knitter explains that with the new height of the door, along with the new beam ceiling, there is a nice header, and when the doors are in open position, it will be almost seamless.
Through true collaboration and a little technology, the team was able to remain faithful to the renewable, affordable style. For more information about the reNEWable Living home, visit www.builderonline.com/renewable.
