Construction tutorial needed

[Arthur Dent81]

I need a tutorial for building construction. The building parts snap on other parts of my construction but for me it is very difficult to make them snap where they are supposed to be (roofs snap on floor parts instead of walls for example).

 

[bamber]

search planet coaster building tips on youtube there are loads of tutorial and Planet zoo uses the same methods. But hold the shift key when placing roof pieces and thumbwheel them up and down