Maybeck was known for using steel sash windows in most of his designs from about 1910 into the '30s - the type you might first associate with old factory windows. His first usage was for the "First Church of Christ Scientist" in Berkeley and it was considered very unusual at the time, 1910. In the Cardwell book, he tells an amusing story about how the steel window representative was very skeptical about the windows being used in a church (Kenneth Cardwell, "Bernard Maybeck" 1977, p.126).
Like most architects, Maybeck was attempting to create an uncommon product from common materials. Steel windows were widely available at the time, but using them in a residential setting, before they were commonly used in this way, in combination with other characteristically Maybeck choices, helped give his works a distinct character.
Around the time that our house was built, he was using Fenestra brand windows - made by Detroit Steel Products Company. They had a factory in Oakland around this time. Seekircher windows helped me identify them as Fenestra. I also found the name Fenestra mentioned below in a University of California report on the status of the historic Hearst Gym.
He used Fenestra windows at least on the Hearst Memorial Gym 1925, Earl C. Anthony 1925-8, our house 1927, the J.B. Tufts #3 house 1931, the Wallen #1 house 1933, Kerna Maybeck house 1933, and the Wallen #2 house 1938, as well as, I would guess, almost everything else he did during that time period. I was able to track down a 1925 and a 1933 Fenestra catalog and it seems that the scroll type decorative bronze handle that he used on all of these "late-period" works was available only after 1925 as it can't be seen in the '25 catalog. He had been using steel windows on most things for 15 years up to that point but it seems when the scroll hardware came out, that quickly became his top choice.
Our windows on the original house also have varying shades of Belgian amber glass, which was quite expensive at the time. Maybeck used colorful glass in his steel windows in several projects like the First Church of Christ Scientist 1910, Hearst Memorial Gym 1925, our house 1927, and the Earl C. Anthony projects 1925-8.
The windows were set in a goopy substance I assume was meant to imitate old dripping lead like in old church stained glass windows. I haven't found Maybeck using this on other houses though he does use stained glass forms at the Earl C. Anthony mansion. At Principia College, he did try and get the slate roof set in a sloppy mortar type way to make it look older and more rustic but it wasn't implemented throughout.
Our steel windows are finished on the inside in a bronze color throughout most of the house. A lot of areas have thin curtain rods inset in the plaster window surround of a similar brass type color that is also matched by the color of the tubing used to make the closet rods. I believe this was to tie together with metallic brass/gold paint that accented the edges of the fireplace. It appears the bathroom windows, on the other hand, were possibly metallic silver - I assume to match chrome hardware on the plumbing fixtures. These details would have all been a part of a spreadsheet on the plans called the finish schedule. The different wood stains would also be on here to coordinate the different characters of the rooms. Besides the brass/gold and silver/chrome finishes - the laundry room window has a purple paint that I think was supposed to match the lavender colored laundry trim stain for the redwood in that room. Before it was a laundry, it used to be a pantry and possibly a servant's quarters. Though Maybeck was playing around with servant-less houses at the time, this client was wealthy, single and getting on in her years at age 57 when the house began construction in 1927
The fading brass/gold window paint can also be seen in some color photos of the late '20s early '30s Maybeck projects like the Wallen #1 house, 1933. Fun fact - apparently our living room also used to have brass lanterns like the Wallen house but they were stolen when the house wasn't occupied for a few years.
If you look close in your Maybeck books, you will see the scroll hardware on pretty much everything from about '26-38.
The Fenestra catalogs, thankfully easy to find and download, are illuminating. They show how steel windows can be quite attractive in residential settings and how modular segments can be combined for many different assemblies with a short wait time.
Above you can see how they had these grid and arch segments that could be combined in a lot of different ways. The grids that hold the glass are made of steel with a T profile - the inside has the top of the T that holds the glass. When you get the window from the factory, you set the frame on the ground, inside face down, and drop the glass panes into place - which are all pretty much the same size if you order it that way. Then typically you would add window glazing putty. After the window is glazed, then you install and paint it. I think the windows were cheaper and more durable than wood windows, but they required more set-up.
The steel windows may have not ultimately been a huge savings, but the different, modernist look they provided ahead of the mid-century modern movement, gave the look and feel of a design that was forward-thinking or possibly cutting edge.