Sure, it can't hurt unless they are part of the admissions board ; )

How would one figure that out ? Is being the program director mean that they are part of the admissions board?

If I were contacted by someone I didn't know, who had similar research interests to things I had previously taught or supervised, I might engage in a discussion about those things.  But if I were contacted by someone I didn't know, with questions about applying to the university, or if gaining an edge in the admissions process seemed to be their main reason for contacting me, then I would refer them to the admissions office.  Generally it won't help your chances of admission to an architecture program to try to befriend faculty shortly before application season.  It might be different if you'd had a longer standing ongoing dialogue with a faculty member, about a particular mutual area of interest - especially if they knew you well enough to be able to write a letter of recommendation - but even then there's no telling how much pull, if any, this particular faculty member has in the admissions process.

The admissions committees in most programs change from year to year.  The committees are usually a mixture of a handful of faculty, a couple administrators, and in some schools there are always one or two upper level current students on the committee. 

Unless the school lists the members of that year's committee on its website or in application materials (unlikely) the only way you could know with certainty who is on the committee is if it's within that school's policies to divulge that information, and you ask. Personally I wouldn't recommend doing so. Contacting anyone individually will come across as sleazy and/or needy.

The reason I'm asking is because I don't want to come across as needy. I'm interested to discuss the work, that's all. 

So, well, after reading your response, it seems like a bad idea for now. It can be misinterpreted. 

Your professors are you biggest assets when you are still a student. Snatch those recommendation letters and job recommendations if you have to, everyone starts somewhere, and your professors will always be there foe you to give you a head start, that is of course if you did well in their classes :). I am also applying to masters program and will ask as many professors as i can for rec. letters. 

As long as your interest is legitimate and you approach them in a professional way, there is no harm in reaching out to faculty you are interested in possibly studying with.  I am many years out of school, but I recall reading a book about getting into college that recommended doing so.

Another option may be to contact said professor to set up a time to speak over the phone or in person if that is doable for you.  This way you are not further filling their inbox over and over with a continuing dialogue.  You can also get a better sense of their personality (crucial if you are looking to work with them at some point) than you would over email.  I would be sure to follow up any phone conversation with a short thank you email. 

Thanks a lot everybody !

Is this grad or undergrad? That makes a big difference. 

As an example, if you're applying to a program MS or March II, the might be a need for you to demonstrate faculty support OR they might pass your name around the faculty to see if anyone would be willing to include you into their research. 

In general, it never hurts to reach out, but do keep in mind that this person may also become a passive reference. "Hey, I chatted with x, and they seem to be..." So really make that contact count. 

It's for a graduate degree.