Although it purports to be a history of (all) architecture, "A History of Architecture on the Comparative Method" (HoA) would take nearly a century and many editions to become anything close to that. The far more Eurocentric and specifically Anglocentric earlier editions treat non-European architecture little beyond its role in influencing later European styles. The 17th edition isn't as explicitly imperialistic as the earliest editions, but still barely scratches the surface of architecture outside of Europe, and has a clear focus on England.

If viewed as a history of European and especially English architecture, with the other chapters being but extra context, HoA is a great resource. It's well-illustrated with elevations, plans, sections, and perspective drawings and photos. Each chapter describes the physical, political, religious, and other influences that produced a given style, and demonstrates a clear through-line from the ancient Near East to Victorian styles.

HoA is a top-notch resource for artists and writers interested in depicting European architectural styles, as it clearly lays out the distinctive features and how they came to be. With this book, you won't accidentally make your fictional Spanish town look French. If you create your own fantasy worlds that don't directly pull from real-world architecture, it'll still give you plenty to think about in terms of how your setting will shape its architecture.

The drawings and diagrams are by far the most useful illustrations, and unfortunately it seems that most of these have been part of HoA since its earliest editions, and the more recent additions to the book are illustrated with photos, which are not as clear and informative as the drawings.

Although it can be used as a desk reference where you browse to the style you're interested in, I think it's easier to follow the logic if you read all the way through it first, as the styles build on each other over time. If you don't want this hefty book crushing your lap too long, read the influences and architectural character sections, but skim through the examples.

Mid-20th century editions of HoA, including the 17th, can be bought online for around US$10-20, which is a fantastic price for the amount of knowledge and visual reference you get. The fifth (1905) edition can be viewed in good quality online on archive.org (archive.org/details/historyofarchite00flet). However you read "A History of Architecture", I hope you do - just don't expect much beyond Europe from it.