Parents/children are known as the Scene Graph in Construct 3 and they allow child objects to transform with certain aspects of the parent object e.g X&Y pos, size, Z-elevation etc.
Containers allow for the automated picking of objects within a container, meaning you do not have to specify the specific instance of an object you are trying to pick when referencing that object in relation to another within the container.
But I believe you may be looking for 'families'. You can add many object types to a family and then execute code on the family. Families can also have instance variables that are inherited by the objects within the family. Families is a paid only feature however.
Elsewise an easy and simple way is to use a single object for your icons and use different animation frames to represent the different buildings.
You could use something like:
On Icon clicked:
if icon is animation frame 1 - create buildingicon at mouse.x,mouse.y & set animation frame to 1
if icon is animation frame 2 - create buildingicon at mouse.x,mouse.y & set animation frame to 2
Every tick if buildingicon exists - set position to mouse.x,mouse.y