A meticulously recreated model of San Francisco's 1907 built "Sentinel Building" we commissioned for Presidio Bay. Model by Peterbar, available on the Presidio Bay Patreon page. This model is ploppable in city builder game Cities Skylines. https://www.patreon.com/PresidioBay
With anything we do with the Presidio Bay project, it takes tons of hours of research to get something just right. The Sentinel building (now owned by Francis Coppola as the Cafe Zoetrope) is a world renowned landmark often photographed with the Transamerica Pyramid looming over it. The key was capturing it "as built" which required hours of scouring online photographic databases, the most fun of which is the https://opensfhistory.org/maps/ which turned up a photo of it circa 1908! Perfectly clear, it guided us to making an accurate copy of it before the ground floor got remodeled a half dozen times in the 110 years since.
I then conferred with Jay who'd be best (and willing) to undertake the project, and through some spreadsheeting, we devised the plan. Once we brought the 3D asset creator on board, I dove deep into photographic and architectural resources, chief among them old Sanborn fire insurance maps, which have accurate dimensions for most buildings in North America cities from ~1870-today. Then from that, using photos, Google streetview/Earth to get the roof details just right.
Another key thing we pay constant attention to is avoiding anachronisms. It takes a lot of knowledge gained over the years to know what types of windows/ doors/ chimneys /architectural details /materials were used and when. Making sure 1910 era buildings don't have wiring, plumbing, satellite dishes or HVAC is important. Even doing proper period correct paint for different years is incredibly important, as many 21st century "restorations" still feature modernized things for code and creature comfort.
Many many hours of texturing and modeling later, we have a beautiful miniature copy of a lovely landmark.
Over the years we've done this for a few dozen buildings, from humble Victorian era homes to the gargantuan 3rd & Townsend Southern Pacific railroad depot that used to stand where the modest Caltrain terminal is today. I should put together a book of the assets we designed and had made/ made ourselves, come to think of it. It'd be very fun.