WHBM it was T1 / 2 / 3 known as Heathrow Central, not just T1. You are being misleading. I might remind you that flying through T1 now means you ARE forced to go through the shopping centre that is the International Dep lounge as domestic search was removed. There is now another security check after security before you are allowed access to the old domestic pier. It's just as long a walk as T5 mate.