Looks like it may be time to put the main build box to rest But having all sub boxs wont be workable ether so how about Build box tabs .
Reduce each type to cats as done BUT instead of switching from the drop down box use popout-up tabs .
Like so roads shows only regular road when clicked a tab pop out showing all roads then just choose the one you want .
Storage shows only materials depot when clicked shows any available storage .
This reduces the main build box to manageable wile combining the main with sub boxs saving time and making the layout neater .
Same thing for types of buildings steel plants start with refinery end with alien steel plant
only a few buildings would be left alone as the late game combo building that make more then one resource .
Entertainment would start with the domed park
the wifi building would become the first education building and so on .,
this should be enough for you to understand the idea .
I could show you a photo from a game taht uses this but not sure it alawed .