Spring Island Residence
5,000 sf wood home, steel moment
Spring Island Residence – R
The Project
A 5,000-square-foot custom residence on Spring Island featuring conventional wood-framed construction over a slab-on-grade foundation. The design is primarily timber-framed with refined residential detailing and a localized steel moment frame strategically introduced to resist lateral loads where required by plan geometry and wind criteria. The project balances a warm, timber-forward aesthetic with rigorous structural detailing to meet coastal performance expectations while preserving efficient buildability.
The Challenge
The project required integrating a discrete steel moment frame into an otherwise conventional wood-frame assembly to provide the necessary lateral capacity without imposing bulky or visually dominant structure on the living spaces. Because the house sits in a coastal environment, lateral design had to account for wind loading and meet code drift and connection requirements while keeping foundation and slab details compatible with the slab-on-grade system. Coordinating the steel frame with floor framing, roof diaphragms and mechanical penetrations—so that architectural intent, finish continuity and construction sequencing were not compromised—also presented a logistical and detailing challenge.
The Solution
We engineered a targeted steel moment frame sized to carry lateral forces through a compact, well-integrated path into the slab and foundation. Connection details were developed to transfer forces into conventional wood framing where possible, and to concentrate steel-to-concrete interfaces in isolated, inspectable locations to simplify construction and future maintenance. The slab-on-grade and footing details were reinforced and sized to accept the moment frame reactions and to control differential settlement at concentrated load points. Diaphragm design of the roof and floors was coordinated so collectors and straps could be discretely located within cavities and chases, preserving the interior and exterior aesthetic. Close coordination with the architect and contractor refined sequencing to allow the steel frame to be erected without impeding other trades.
The Improvements
Introducing the steel moment frame provided a robust, compact lateral-resistance system that avoided widespread heavy framing. Foundation and slab reinforcements concentrated where the frame reacts improved long-term performance and simplified inspection. Detailing to isolate the steel-concrete interface reduced thermal bridging and provided durable, maintainable connections. The coordinated diaphragm and collector design allowed clean interior finishes with minimal exposed structural hardware, and construction sequencing reduced rework and improved schedule reliability.
The Results
The integrated structural solution delivers the required lateral capacity while maintaining the intended timber aesthetic and efficient wood-framed construction elsewhere. The steel moment frame is visually unobtrusive and concentrates required strength in a small, serviceable footprint, allowing the residence to meet code and performance expectations for wind and seismic loads. Reinforced slab and connection detailing provide confidence in long-term stability and minimize the risk of differential settlement or unanticipated repairs. Overall, the project achieves a refined balance of performance, buildability, and visual warmth suitable for a high-quality island residence.
