What evidence do the police need to raid a house in the UK?

Im just curious really, Im currently doing a small ish grow, nothing i think i would go to prison for but being a true stoner i sometimes wonder if i would get raided....

What evidence would the police need to raid a house in the UK, could they just raid a house from someone tipping them off?
i.e. someone that maybe found out your growing and decide to screw you over?

Thankfully I'm not in that position but am curious lol

all depends on the jude ,
they will watch for a while see what your doing , maybe check your house for heat with a handheld F.L.A.I.R
or some one could tell them thats if they know about your grow , but i know its not as simple as just getting a warrant signed and then run in all guns blazing ,but then again , in middlesbrough the police can just get a warrant over the raido and then come in

Im not too concerned about police turning up at my house or anything like that, i grow in a tent, vent indoors and use ona products to remove any smell i think there might be after the carbon filter has done its work lol
But it still doesn't stop me thinking "What if" every now and again
There's only a few houses that overlook where i grow and Im always cautious about when i open the tent up so not to bring attention to the light coming from windows.
I've never been in trouble for mj, i pay my electric bills on time, my partner even used to work for the police and i keep myself to myself but you just never know lol

Depends on where you live.

If you live in a state where it's legal don't worry about it...just keep the smell down to keep unwanted visitors away. ( Curious teenagers etc ) Glade plug ins work great...stay with Vanilla or Coffee..Caramel works good too.

If not, keep it small. odor free, no light leaks etc...and tell no one !

Keep it secret, keep it safe...

Hi I have a house coming up for rent, if anyone would be intersted, elec gates and two rooms kitted for growing atm, if the money is right then it is yours to use, mesage please.