The oil filter on the 1.8 is on the front of the engine on the left hand side but is low down where the sump is. you may not be able to see it without taking off one of the shields under the car. It is in an easy location to do your own oil changes once the car is out of warranty
Honda-Tech.com: Honda Civic (2006 - Current): ** DIY: R18 Civic DX/LX/EX Oil Change **
This link is for the US version but is the same engine.