avo provided some very thought-provoking questions about modernist architecture for houses in Vietnam on my posting of HCMC House 12. Rather than provide a response back in the comments to the posting, I want to publish it here for greater visibility as well as to get back into posting about Vietnamese modernist architecture.
avo asked "does any of those angle facade elements have anything to do with the surrounding environment?" The direct answer is no, which is typical of modernist architecture for houses in southern Vietnam. The surrounding environment is usually more houses of the same form and height. Since the only exposed part of these houses is the street facade, the style of architecture can be expressed here and therefore can reflect the tastes of the owner or the architect or contractor. Some of these houses will have traditional styles, while many will be modernist. While the choice of a traditional style can be considered to be an emotional choice (at least I see it that way), a modernist composition becomes much more intellectual in the many choices that must be made regarding materials, finishes, textures, forms, lines, and colors. In the traditional style, these choices are prescribed by the style itself.
In this case, the architect's organizing principle is the composition of angled forms and the warped surfaces. The only objective is to make a pleasing composition using the window and door framing within the openings. This leads to avo's implied question in this statement: "The house might have its own appearance (maybe a different look with other typical Vietnamese "tube" house), but modernist architecture might have been gone deeper into functional rather than aesthetic look." That is historically true of modernist architecture -- "form follows function" has been a major principle of modernism. In this case, the architect has brought the exterior skin in front of the structural frame to address the function of keeping the weather out of the house while allowing views out. But this function must be accommodated in every house. What is different and important here is the intellectual choices made to carry out an unusual idea about the warping of surfaces.
avo also asked if the design of House 12 depends on "uses of occupations? or nothing but just the style of the architect?" I believe the style of the architect is the architecture of House 12. As I have stated above, the principles of Vietnamese modernist architecture for townhouses deal with resolving the functions of structure, weather proofing, ventilation, views, and light for the house, but most importantly, involves presentation of an intellectual idea that is expressed in the composition of the facade. I have not determined any differences in modernist facades that indicate either an occupation of a home-owner or of any commercial activities that might occur in the house. On the other hand, the ground floor facade of houses along busy streets does relate mostly to the commercial activities on the ground floor, and usually has nothing to do with the design of the house above.