Sometimes its whats within the walls that counts. In a toss up between expensive wall finishes and layering elements, unless we're talking about a padded cell or something like that, I always ditch the wall finish. Wall is BG. Layers are FG.
Layering elements give a set a sense of depth, in the case of using colonnades, or columns. The viewer can only see that there is space beyond, obscured. This can help to create suspense, or on the other hand it suggests scale. Colonnades are particularly loved in set design as they are functional to the filmmaker and to the design construction. They allow a series of rooms to be visible from one to the other, giving the camera more freedom to shoot. They help the room from being subjected to boring.
Factories and industrial facilities have vast layers of metal
framing, pipes, conduit and materials. Great scenery for hiding,
stalking, predator shots. Storage rooms and maintenance areas likewise
are all great scenes for firearm scenes, where things can get hit, spark
and explode in frame without causing overall set damage.
Layers such as ornamental wrought iron create mystique. They look awesome in horror films. Confession booths are the classic layer look. A classic perforated metal, cloverleaf, is a really common grille. Looks beautiful with candlelight. Confession booths are a common build because in reality they are too small to shoot in. Other layering elements can be greenery, as seen in Legend with the use of Lilies. A trellis is also a good example of a greenery layer. Fabrics are beautiful in a window; nothing says 'its windy' or "theres a bad man outside' more than disturbed window dressing. Soji and other types of screens are also a great solution. Especially on a location where there is no build involved.
One note of caution; Stringy curtains and fine meshes can cause a moire effect, which you really don't want. There's nothing worse than annoying moire in the BG.
Most DOP's love to shoot through layers. They are a naturally occuring FG element that are a vital tool for a filmmaker, and will utilize them to create interesting and beautiful shots. They are an opportunity for creative lighting and can cast the most amazing shadows.
The walls sometimes just end up being a frame. Sometimes they don't even get seen.
It depends on the movie you're making.