Low voltage supplied to building from meter room, located at first basement level, and distributed via (wall/floor) openings to various floors/levels

itès what you put service cables & tubes in, in a building

Whilst agreeing with the previous answerer, I'd also like to propose this alternative, which may be appropriate, placing as it does less emphasis on the vertical nature [which IS, of course, implied in 'tremie']; however, in my experience of electrical instalaltions, I'd say that 'duct' is probably more likely to be encountered, and such additional precision is somewhat superfluous. And 'duct' certainly CAN be used for something vertical as well as horizontal