The vertical surface enclosing your project can be understood as either a membrane – a think veil separating inside and outside – or as a wall – a solid which requires mediation through windows, gaps or openings. The skin or membrane is generally a surface whose primary determinant is the exterior image. That is, it is a skin which wraps the building and whose articulation – joints, ribs, and pattern – is generally graphic in quality rather than directly determined by the interior.
The wall, by contrast, is articulated as a more solid and thicker surface that tends to act more as a mediator despite the fact that they are generally more opaque than skins (which tend to be transparent or translucent). Because the wall establishes an unambiguous limit (visual and physical) there is generally a tendency to be more considered about how connections are made between the interior and exterior. That is, windows are generally set with a greater concern for specific and framed views. Balconies or other punctures act specifically to join inside and outside. As such, although one may see less of the interior through a walled project than as with a skinned one, the relationship between inside and outside can be said to be more precise.
Paradoxically it can be suggested that skins, though often (but not always) permeable tend to draw attention to the surface as an object – a plane – and hence create a stronger barrier to interior/exterior relationships. Walls, through the more carefully and selective connections can act more as a connective surface linking inside and outside in a constructive manner.