Proactive Design: Integrate Structure Early to Elevate Design and Lower Costs

Julian Lineham, PE
Studio NYL Structural Engineers | The Skins Group

Because every building’s form is ultimately defined by a structure that is integral and essential to the success of the design, tapping structural engineering expertise at the onset of the design process seems like a wise strategy. But not every architect understands or does this. Collaboration with a structural engineer at the very beginning of a project not only can accomplish higher-quality architecture, but also it achieves better integration with the structure, and enhances the design.

If the correct structural system is selected early on when concepts are still fluid, it forms the right bones for all that follows and inherently reduces costs due to its appropriateness and efficiency. In fact, structure, when considered proactively, often can become the architecture through its overt expression of architectural form, or its articulation of structural details. Exploring a building’s structural design holistically, and embracing all of its elements – including façade and MEP systems – ultimately results in a better building. To that end, we encourage involvement of all design team members, contractors and key subcontractors at the genesis of a project whenever possible.

Christopher O’Hara, PE
Studio NYL Structural Engineers | The Skins Group

But, in our experience, many architects and designers still begin projects thinking: “I’d love to fully realize my vision and push the design to its greatest potential, but that would be too complex and expensive.” As a result of assumptions like these, the vision is immediately dialed back and taken down a different path, ultimately compromising the original intent. Only later, sometimes much further along in the design process, do architects bring in their structural engineer and discover that they missed out on numerous opportunities that would have made their project better, more efficient, less costly, or just more aesthetically beautiful overall.

In cases like this, we often find ourselves asking questions like: You seem to have strayed from your project vision and goals; is this design fully expressing what you were originally striving for? Or, are you aware of all of the efficiencies that could have been easily addressed if we’d been engaged from the start? This is when clients realize that although it would be best to explore possibilities in a more innovative way, too much time and effort already has been invested in their design to unwind the process and start again.

We want to hear, on Day One, all the crazy or wild ideas our clients would ideally like to achieve. Most have learned that it’s to their benefit to start early, and to be highly proactive when it comes to structure. They’ve also learned to never say, “This is how we did it last time, so we assumed this project would be similar,” because similar precedents do not always apply in these scenarios. Not all engineers welcome the opportunity to collaborate in this manner, however, as it requires more time and increases their costs. Thus, building a team as passionate about design as the owner and architect are, is critical.

Hearing an architect’s vision, philosophy, goals and design ideals early in the process – ideally during the conceptual design or very early schematic design phases – allows us to explore potential possibilities together as team. This is where a wide diversity of ideas are tested, and ultimately accepted or rejected, in addition to exploring various traditional and nontraditional schemes, structural systems and materials. It is also important, during this exploratory period, to record any discarded ideas from the cutting room floor as they may have relevance as the project evolves. In terms of “appropriate structural systems,” we suggest that the following elements be considered:

Strength/Stiffness/Ductility/Weight/Fire Resistance. Lever-
aging these traditional metrics result in building efficiency, cost reduction and, often, lowered loads, which result in reduced foundation costs. Early integration of architectural façade, interior finishes, green roofs, and renewable energy photovoltaic or solar thermal systems, for example – or planning for their possible future addition – greatly minimizes build-out costs later.

Holistic Integration of MEP Systems. Examining MEP systems early will determine if it make sense to run air- conditioning and heating services, wiring and piping through the depth of the floor and roof structure. If, for example, there are zoning or building height issues, or a new building has to be constructed within historic façade pattern restraints, or the client or market desires interior headroom heights that can’t be achieved by placing MEP systems beneath the structural floor zone, then exploring these ideas early can cut costs dramatically. Considering nontraditional systems, like castellated or cellular floor and roof beams, or beams with prepunched openings, are also a critical part of a proactive structural strategy.

Aesthetics (Exposed Structure). The final look and feel of a building’s aesthetics, where the architectural goal is to leave the structure exposed, should be explored early as well. In cases where the structure is designed to be a part of the architecture itself, the selection of structural system materials and details, which would traditionally be hidden, must be carefully thought out. Important questions include: Does it help tell the story or become part of the architecture? Does it provide a raw industrial feel using exposed concrete and/or steel, or warmth to the space with exposed timber? And how do we accomplish maximum possible transparency with minimal or no glazing mullions in both exterior and interior glass walls?

Constructability. Site constraints often direct a team to utilize a particular structural system due to natural synergies with the construction method. Thus, to assure speed and economy of the building process, it is important to determine, in advance, potential issues like: buried obstructions or utilities that may need to be spanned over to avoid expensive relocation costs; the need for integration of structure with shoring or other temporary works; or panelization/modularization systems that would potentially limit crane use.

Sustainability/Life Cycle Cost/Ease of Reuse/Demolition. If a project has elevated LEED or WELL goals, structural systems must drive toward these goals from the onset of the design process. Questions like “Does the use of new technology or processes help achieve these goals?” go a long way toward coming up with the right solutions before the design is set in stone.

Bottom line? Exploring ideas and options with a structural engineer during the early phases of a project not only helps the design team guide it down the right path, it limits compromises to the architect’s original vision. This approach elevates team members’ understanding of a project’s parameters, which allows the highest-quality design and most cost-effective outcome for the client to emerge. \\ jlineham@studionyl.com cohara@studionyl.com Twitter: @studionyl

Featured in Building Dialogue, March 2016