Architecture = the design and construction of buildings (structures) and development of sites

Urban Design = the design and construction of a physical place in and between sites, i.e., the development of pathways and open spaces to their sites forming delineated groupings of similar objects (blocks and neighborhoods)

Urban Planning = the design and sometimes construction of greater physical places and legal frame work between interrelated neighborhoods forming organizational and legal entities (subdivisions, towns and cities)

Metropolitan and regional planning = the design and sometimes construction of greater physical places and legal frame work between interrelated subdivisions, towns and cities forming organizational and legal conglomerations of areas with similarly-related economic and social demands (metro, countries, regional government)

In some countries Urban Planners even determine the color of the front doors.

There's been a lot of discussion on this topic over the years. Enter "urban design" in the search field at the bottom of the page, and you'll find a slew of opinions.

Sub,
I did the MAUD degree (had a B.Arch) because I wanted to develop a skill set to deal with the larger, more complex problems of city/district/region,etc design that I didn't feel like I learned in my undergraduate program. After I graduated, I took a job in a large office in the Architecture Department, have worked on several Architecture and Urban Design projects, and am now considereing the switch to the Urban Department....

So i guess, it all depends on what you want to do with it.... and the flexibility within the program (are the studios integrated, or are you locked in to only UD/Planning studios, etc).

I believe it depends on a number of things. How the university defines its programs for one thing. There is a difference between design and planning and my school defines city planning as a more "policy" based program then design oriented. Planning as less about proposition and more of understanding cities as culturally and socially complex systemic organisms; understanding to enact sustainable growth plans for example. You are more apt to be working for a city government. Urban design is more broad-based architecture that dwells more on the proposition and macro-design; defined more as a physical proposal. Similar to your post UG.

I say, the gap in terms of definition between Architecture and Urban Design is getting wider each year. UD (Urban Design) was a subset of Architecture back then; but these days, it has its own thing going on already.

Job prospects: taking Urban Design would mean wider job scopes , and unless you wouldnt mind working for an urban developer/firm, I say go for this

taking M.Arch on the otherhand would be mandatory these days for you to be a registered architect someday. Also, M.Arch furthers your basic knowledge on architecture that you have learned on your B.Arch degree. And believe me, that B.Arch skills you acquired is just a small thing once you get into the real world my friend. my 2 cent advice.

goodluck

what is the difference between urban design and urban architecture?

It all depends on the definition one prefers to give it. For me, it includes the architecture on the ground plane as well, and the design of the exterior as well - as an object in the urban field.

Old thread I guess, but I think Distant Unicorn summed it up best. There are no hard-line definitions, but you might say the scale of design goes something like:

Interior designers: the most personable of spaces, interior finishes, program, budget, wall layouts, etc

Architects: the building form, scale, facade, orientation, program, and wall and structural detail, budget, etc

Urban Design: the building (s) layout, proximity to natural features, coordinating trail networks, proforma and development numbers, site analysis, streetscape, etc

Urban planners: "same as Distant Unicorns definition"

I work as a Urban Designer and usually just tell people I make maps for a living.

I ended up with master of architecture and master of urban planning. My understanding was before planners existed architects filled that role. Then architect focused on the building sometimes the site around it. 

Planners everything around the building and the next. Then planners specialized into planners - policy, people interaction, zoning, scale city or regional both have their scopes depending on area the work in. Then designers they design the physical space and suggest policy, designers also specialize in different areas: urban, regional, environmental, traffic, etc.