Sounds like a use for the general article template
I think what the author is missing is a link in the building template to another building, something like what we have on items where you can have an item modeled after another item.
This sounds like a cultural thing(and hence, something you'd do as a tradition)
Honestly, Wingshaw's idea of a Style template is really cool, and I think that would definently spawn some worldbuilding ideas and articles that we currently don't see much off (though I am aware Traditions kind of cover that already).
I definitely appreciate the want/need for an article about a generic type of building in a world, but unfortunately I don't think it warrants its own template. It might be a tricky thing to make work in the existing building template, though it probably could be done. Personally, I would opt for a generic template to make it easier to describe whatever aspects are relevant to that type of building and its culture. For architectural style, I think tradition might be a good idea, since so much of architecture is informed by the culture its built by/for. A side note I want to echo about the buildings template is how it does say it's for specific buildings and landmarks. As seen in UnknownWriter88's shared screenshot, it says, "Anything that you can point to and people consider significant enough to name." Maybe a change in its description is a nitpick for another day, if (and a big if) it's now also meant for all buildings, specific and otherwise. I think you raised a fair point, just not as its own template (although Wingshaw's suggestion of a Style template is intriguing). So maybe the next step is to think about and suggest more specific fields for existing articles, directed at describing a generic building?
While I don't think this suggestion is entirely necessary, I think some of the responses to OP are missing the point. OP knows that the Buildings template and the Traditions template exists, but they describe specific objects, rather than generic ones. Maybe an alternative form of this suggestion could be a new template for Styles: style of art, style of clothing, style of buildings etc.?
You can either use Building or Tradition if for example you want to talk about the Neoclassical style.
Many article templates work just as well for a class of entities as they do for single named/prominent entities. I've done a Terps Settlement article, and then individual Terps with individual Settlement articles.
We already HAVE a building template (on the dashboard) that works for houses and other structures. Also, you can follow the prompts at the bottom of the article (click "Show Template Specific Prompts & Connections" to see them) to answer most of the questions you mentioned, or you can just fill out the vignette (first large empty box you come to when opening an article) with whatever you want along with custom headers.