Dynamic Texture Tiling

What I'm trying to do is allow users to draw groups of objects as a single mesh. Like building walls in an RTS. Initially I tried to simply spawn a bunch of unit cubes but after awhile my FPS really started to drop.

What I thought I could do instead was to scale a single unit box along a single axis and then tile a texture along that axis to simulate having multiple cubes. The problem I'm having here is that while I can dynamically texture the object just fine I find that on the non-scaled axis the texture gets bunched up. The only other way I can think to do this is to define a "cube" class that uses planes as walls where I can specify texture tiling on a single wall.

Anyone have any suggestions?