Our code requires all mechanical, HVAC, electrical, etc to be screened. How? It doesn't say. Therefore, anything is game. A disgusting practice here has been to screen mechanicals on rooftops with fencing.. stockade, shadowbox, and even slatted chain link. Technically, it meets code and the intent. Practically, it looks like ****.
I know that raising parapets is a good way to screen the rooftop equipment and avoid the fence issue. Are there any other solutions I can encourage?