"Ged McLaren" wrote
Planted my first Wisteria earlier this year and its growing well,what do I
do when then vertical shoot reaches the gutter of my house ?

Should I pinch out the growing tip, or train it horizontally or what ?,

You should decide where you want it to go over your house and then screw in
vine eyes along the lines of the cover you want and tie strong galvanised
wire between them, then train the shoots along these wires ( tie them
loosely as they expand with growth).
As you have your parts of your framework complete then don't allow any more
long shoots to grow from them, cut them off at 3 buds or so (constant job
throughout summer) to save the plant energy and keep it tidy.
Ever winter cut all shoots coming off your basic framework back to 2 buds to
encourage flower spurs/buds.

--
Regards
Bob H
17mls W. of London.UK