This is the parking space they have and sometimes there are one or two staff cars already there. I would suggest you get there very early when they open up and you might be lucky.
This is the Glenside Pub on Landscape Road which is not too far to drive to for lunch. You could walk it as well though.
Forgot to mention, ring the bell, explain who you are and reason for visit, you will be buzzed in. There are lockers inside the front door where you leave all your gear, coat, bag, they don't allow any recording equipment like a camera. Take the locker key with you. You can bring a laptop, notebook, pencil with you, they have pencils there anyway. Go up to the first floor office and you will be looked after at the counter.