Although I am not specialising in economics, I have done two economics modules this term. Lectures and tutorials have been held primarily in University Place (the building that looks like a tin can), with half the seminars in Roscoe Building.
Grosvenor isn't too far away, but I'd suggest having a look on google maps to get a feel for the distance
What are the contact hours for L102 (lectures and seminar) and where are they usually held at?
I am thinking of staying at grosvenor park. How far away is that from lectures and seminars?
I do Economics. In your first year you normally have 2 (1 hour) lectures per module (regardless if its 10 credits or 20 credits) and a seminar every week (but sometimes every two weeks). It works out to about 13 to 15 hours of contact time not including the time you can spend booking a one-to-one meeting with a tutor.
Lectures in first year are primarily in the University Place building which is quite nice. There is also Roscoe as well. They are basically the main places which can house all the students (people suscribed to the courses can range from 150 to 600+ students, but this doesnt mean all of them turn up to lectures lol).