Grid or blueprint approach with no perspective, and a more subtle, lowercase, "construction" word. "t" connects to the design for an added reference to "building" or "structure".
I think all of your ideas are great. Can you build on #27 making the background wider and the image taller and on the left? I really like the blueprint idea of #26 and the simplicity of #28. At this point I think #27 stands out more and would work better as a sign or on on a vehicle.
Regarding #27. In addition to my previous comments could you make the ends of the roof and the bottom bar run a little bit longer than the lettering? Thanks
Alternate with roof and foundation expanded in a more succinct, square layout. Not sure what you meant by the "image on the left" part - but I'll be happy to create more alternates on this concept based on your suggestions.
Alternate without any divider between the text but including more spacing in between the elements. The roof now is also taller by comparison making this version the tallest of these three new ones. Please supply any other variations and mixes you wish to see.