Building circuits with BuildCraft
Solution 1:
Unfortunately, Buildcraft is not compatible with ProjectRed.
There was a convenient article I found was on the BuildCraft FAQ, under the section What mods do the BuildCraft Builders support?, which gave me this information:
In the second list, there is an item called RedLogic. This mod is the replacement for PR2 which is why there is no support for for it on this list.
To sum up, you cannot use the BuildCraft Builder for ProjectRed specialty blocks.