Project Highlight: The Sky House

Steel In The Right Places

At the back of the building, the structure begins to tell its own story. What looks like a simple frame at first glance quickly reveals something more complex. Multiple steel members form a network that supports a series of stepped and cantilevered architectural elements. Each of these moments reflects a deliberate design move by Feldman Architecture, who envisioned a rear facade that breaks from flatness and brings movement to the building’s form.

This geometry introduces unique challenges during both design and construction. No two planes align in a standard way, and the shifting volumes require custom-fabricated steel to meet exact tolerances. Each beam and column arrives on site pre-fabricated and ready to fit within a tight field assembly process that leaves little room for adjustment. Behind the scenes, this demands an intensive round of coordination, shop drawings, and structural review long before the steel ever hits the ground.

FORMA and their partners have worked closely with the design team and fabricators to ensure that each piece performs not only structurally, but in service of the final architecture. The steel sets the tone for everything that follows—from the placement of windows to the cladding patterns still to come. As the siding is installed, you’ll begin to see those architectural rhythms emerge.

Even in its early stage, the clarity of the design comes through. It is a form shaped by precision, thoughtful coordination, and foresight — already standing as one of the defining features of the home.

Sealed To Last

In San Francisco’s foggy, moisture-heavy climate, waterproofing is not just a box to check. It begins early, with systems designed to handle long-term exposure. At this project, FORMA and their partners are applying a liquid membrane that seals the structure from water before any finishes are installed.

Unlike sheet applied systems, this waterproofing is brushed or rolled on. It forms a seamless, flexible coating that adheres tightly to the wood sheathing and framing. Because it is applied as a liquid, it wraps around fasteners, corners, and openings with full coverage, leaving no gaps or seams.
What you see here is part of that process in motion. The black coating around windows and edges is the first phase. As work progresses, the full exterior will be covered to complete the continuous barrier. Each rough opening is sealed early to protect vulnerable areas before windows and flashing are added.

Scaffolding gives the crew access to every face of the building, but the critical work happens in the details. It may look simple, but this coating plays a vital role in the building envelope. FORMA treats it with the same care and precision they bring to every stage of construction.

Holding The Hill

In San Francisco, where excavation often happens just inches from neighboring homes, even digging requires careful planning. At this site, FORMA Construction and their partners followed a precise sequence to ensure safety, stability, and long-term performance. Narrow hand-dug pits were excavated in alternating sections along the property line. Each one was carefully braced and filled with concrete to support the neighboring foundation before the next was started.

Once the first round of concrete segments had cured, the remaining gaps were excavated and filled to form a continuous structural wall. You can see the clean lines left by the formwork, the rebar extending for future connections, and the regular pattern of form tie holes. These walls are more than structural elements. They are part of a carefully managed process that prepares the site for the next phase of construction.

Behind the wall, a waterproofing membrane was installed to guard against moisture and support drainage. The extra material is intentionally left exposed so it can be overlapped and sealed into the next section when the adjacent wall is formed and poured.

Every part of this sequence reflects experience, collaboration, and respect for the craft. These are values that FORMA and their collaborators bring to every project.

The work is still unfolding. The best moments are still ahead.
We’re grateful to be building and documenting it as it takes shape.
More stories soon.