1. Design for the load case, not the weight
The frame carries the panels, but it also has to resist someone leaning on the wall, a service technician pulling a panel forward, and any building movement. Design for 1.5 times the dead load as a minimum, and add a horizontal point load of 0.5 kN at any accessible height.
2. Flatness tolerance in writing
Specify 1 mm per running metre, maximum 3 mm over the whole wall, measured with a laser or a straight edge. If the drawing says 'flat', the fabricator will interpret that as 'looks flat'.
3. Vertical members at panel joints, not in the middle
The frame should support each panel at its edges, so the load goes into the steel rather than through the panel. A member behind the centre of a panel does nothing useful and blocks the service access.
4. Service access from the front
If panels are pulled forward on hinged mounts, the frame needs a clear return path of at least panel depth plus 100 mm. If access is from behind, the room behind needs 600 mm. Decide early; it changes the whole layout.
5. Thermal movement
Steel expands about 12 microns per metre per degree. A 12 metre wall in a room that swings 15 degrees moves 2 mm. That is fine if the frame is allowed to slide at one end and bolted at the other. It is not fine if both ends are rigidly fixed.
6. Cable routing inside the frame
Allow a 50 mm conduit path per column and a horizontal tray at the top. Cables laid loose between panels will press on the back of the modules and eventually cause pressure marks on the image.
7. Earth bonding
Every frame section should be bonded, and the resistance to earth should be under 4 ohms. This is a safety item and also a noise item: a floating frame picks up interference that shows up as faint horizontal lines.
8. A datum mark
Weld or punch a datum on the frame before it leaves the workshop, and dimension everything from it. On site, the installer aligns to the datum instead of to the wall, which is never straight.