Board Thread:General Discussion/@comment-25000380-20150411174549/@comment-7620285-20150413143247

the simplest way to gain EXP is to collect resources.

the problem is you can't collect resources once you reach your maximum supply, so we have to figure out ways to deplete resources. for this reason, many of us purposely leave a Parliament building at Level 9 and choose upgrade -> cancel in order to evenly deplete the 3 resources. You don't gain EXP from upgrade+cancel, but it allows you to pick up more resources from the farms over time.

other methods require a lot of micromanagement... if you sell a building and then start it from level 1, the first level probably doesn't give me EXP and completes very quickly.... so you'd want to check back soon just to upgrade it to level 2, which takes a little more time and only gives a little more EXP.... this is not very fun for most people, so that's why we resort to the Parliament upgrade/cancel idea.