neighbour's cat peed in my house! how do I...

[bumpertobumper]

How do I get rid of the smell?

I left the window in DDs room wide open yesterday, it looks over a flat roof. Now the room and landing stink of cat pee.
I have crawled around trying to locate it but it is tricky as the smell is so pungent my nose seems to lose sensitivity.
I don't have a cat. It is annoying but I can put up with the odd poo in the flower beds, but coming into my house and stinking it up is too much

Anyway, advice please on how to get rid of the smell... Please!

Oh god you have to find it! Are there any dark patches (carpet?)? It will probably be around the edges of the room or in a corner.

When you find it, spray it generously with a water and vinegar mix and scrub. Once you've neutralised it with the acid, you can use washing up liquid on a sponge, then when it's dry, bicarbonate of soda sprinkled (again, generously) and left for a few hours/overnight, then vacuum.

Oh its really not pleasant! I had a cat that started this dirty habit after being attacked and then being afraid to leave the house. I spoke to our vet and he recommended using biological washing liquid, mixed with warm water. Apparently it breaks down the enzymes in the pee which cause the stink, which will hopefully reduce the chance of the naughty cat returning to re-mark. Good luck!

Thanks for the tips!