Hi everyone, I am new here!

Just wanted to aske about my dogs growling
He is just over a year old and is a border/bearded collie mix.

We moved in January to a new house and since we have moved he growls everytime someone walks past our front door.
He growls and runs to sit next to/behind me or jumps in his bed if I am not around.
If someone knocks at the door, he is ok no growling but if someone walks past or next door is going in or out he starts.

Our old house had a front garden and was quieter. This house opens right onto the street and next doors door is right next to us! Could this be it?

Why is he running to me? Is he trying to protect me or have me protect him? Is this behaviour ok?

How can we stop this? He never ever growls any other time and shows no aggressive behaviour at all.

Thanks for any help you can offer