If you want to become a professor in architectural history/theory, I suggest looking at M.Arch programs you'd want to teach at and see where those profs went to school and what their path was. 

You can get a PhD in Architecture, but there are PhD and Masters programs in Art and Architectural History that may be better suited to your interests.  These programs are research, reading, and writing heavy; there is no drawing, studio work, designing component. (I came from a BS Arch program, hated studio, and got a Masters in Arch History instead with the intent to get a PhD in Arch History as well. Chose to pay off my masters instead and got licensed.) Society of Architectural Historians has a list of arch/art history graduate programs in the US that may help you: https://www.sah.org/docs/defau...  This is what I used to start my grad school research.  You may also want to look into Masters programs in Historic Preservation as they may give you a more employable outlook while still allowing you to do the research you're interested in.  Many preservation programs require an internship/work experience in the field which also helps you understand the what the field requires, types of jobs available, and future employment.

Another consideration is that it is extremely hard to get a job in academia after PhD. There are a lot of PhDs and not a lot of jobs. It is advisable to get another skill that will help you whether it is architecture, historic preservation, drafting/modeling, etc. 

Hi OP,

based on the information provided, it seems like a 2/3 year professional degree doesn't appeal to you. And that's fine. Actually it could be great. You've already identified specific interests - these areas of interest may change - but it comes across that you are more interested in cerebral thought processes and theory, that doesn't necessarily mean the production of buildings. Good! We need more of this. Architecture is a relatively well established and stable profession- like Medicine - but unlike Landscape Architecture. A profession is really a fiction. It's a system of ideas about competencies and requirements built up around something so that there can be a general consensus about how one should go about doing things. But you're not interested in this are you? Don't let the structures of one profession limit you because you are interested in the discipline. The discipline of architecture, and the profession of architecture are two separate things. You don't want to be a professional architect: that's fantastic! Focus your energy only on where you think you can contribute the most.

I'd recommend exploring the History and Theory courses of good schools, and get a sense of the background and path the individuals who taught these courses took. Many of them may have studied architecture. But you don't need to study a professional degree in architecture to be a professor in the discipline of architecture. Maybe you don't even need to teach in a school of architecture to talk about architecture? Broaden your references a bit, look at liberal arts programs (like Nature Culture Sustainability Studies at RISD), look at Fine Art, Design and Landscape Architecture programs. Don't jump into doing a masters. It's a huge step. Take enough time so that when you've made a decision, you're certain.

"Another consideration is that it is extremely hard to get a job in academia after PhD. There are a lot of PhDs and not a lot of jobs. It is advisable to get another skill that will help you whether it is architecture, historic preservation, drafting/modeling, etc. "

Tatoo this on your forehead. 

you really should be looking specifically at who are the contemporary architecture writers and thinkers you admire and focusing your plans on studying in programs and schools where you can work with them. your interest is already quite specific; an m.arch from a geographically convenient school might not help at all.

Yes, in your situation, you should do an M.Arch.

Fewer and fewer architecture schools have faculty members who do nothing but teach history and theory. Many expect those faculty members to be able to teach studio as well. An M.Arch. will assure future employers that you are qualified to do that. Spending at least a couple of years working in architectural firms will help, too, while broadening your ideas about architecture.

However, it doesn’t sound like there’s any point in you taking the AREs or becoming a licensed architect. Getting licensed would simply help you keep a foot in the world of practice after you start the PhD.

For most universities, the M.Arch. is considered the “terminal degree” in architecture. This is important because it opens up possibilities in terms of what academic positions you can fill and how much you are compensated. From their point of view, a PhD would just be a cherry on top, even though for your own sake it is necessary if you’re serious about history and theory.

Many M.Arch. programs offer merit scholarships that can pay for all of your tuition and fees, and sometimes even more. You could graduate will little to no debt, even after accounting for living expenses. 30k debt is a lot. With a scholarship, you may be able to attend a top-tier East Coast school and owe less at the end!

Depending on the program and its electives, you can take lots of history/theory classes as part of your M.Arch. degree. If the program includes a thesis component, you may be able to do a written thesis that would lay the foundation for your future research and writing.

The only sensible alternative to doing an M.Arch. before you do the PhD is to change routes completely: go into a humanities or social sciences PhD track (anthropology, sociology, etc.). You could even study architectural history within the field of art history. Yet each of these options is a totally different world compared to the world of architecture schools. Many architecture schools won’t even hire someone with that kind of background. lnstead, you would be preparing yourself to teach in either art history departments, anthropology departments, sociology departments, or liberal arts colleges.

Family and finances are understandable reasons to want to stay in LA. However, if you are willing to consider leaving, then look at many more programs in other states. You want a program that will give you lots of access to a greater number of top minds doing work in history/theory, especially the kind of history/theory that you’re into. MIT and Columbia are good places for this. So are Princeton, Cornell, Yale, and Harvard. Look into the University of Michigan and the University of Virginia. It’s true that finding the right “fit” is important.

One last thought: you can’t know what will make you happy until you’ve tried it. My opinion is that, if you can get into them, top-tier M.Arch. programs would be very gratifying, better prepare you for a PhD, and put you in close contact with leading historians/theorists that will also propel you toward your future work.

By the way, yes, it’s a good idea to have an M.Arch. to fall back upon if the academic route doesn’t pan out for you. Academic jobs are getting more and more competitive every year. There are way too many people who are highly qualified for these positions relative to how many of those positions are available. (See The Professor is In by Karen Kelsky.)