The vast majority of Red Gate is on the first and second floors (the second and third floors in US parlance) of an office building in Cambridge Business Park (here we are!). As you can see, the building is split into three sections; the two wings, and the section between them.
As well as being organisationally separate, the four divisions are also split up in the office; each division has it's own floor and wing, so everyone in the division is working together in the same area (.NET and DBA on the left, SQL Tools and New Business on the right). The non-divisional parts of the business share wings with the smaller divisions, again keeping each group together.
The canteen
One of the downsides of divisionalisation is that communication between people in different decisions is greatly reduced. This is where the canteen (aka the SQL Servery) comes in. Occupying most of the central section on the first floor, the canteen provides free cooked lunch every day, and is where everyone in the company gathers for lunch.
The idea is to encourage communication between the divisions; having lunch with people in a different division you wouldn't otherwise talk to helps people keep track of what's going on elsewhere in the company. (I'm still amazed at how the canteen staff provide a wide range of superbly cooked food for over 200 people out of a kitchen in which, if you were to swing a cat, it would get severe head injuries.). There's also table tennis and table football tables that anyone can use, provided you can grab them when they're free!
Office layout
Cubicles are practically unheard of in the UK, and no one, including the CEOs, has separate offices. The entire office is open-plan, as you can see in this youtube video from when we first moved in (although all the empty desks are now full!). Neil & Simon, instead of having dedicated offices, move between the different divisions every few months to keep up to date with what's going on around the company; sitting with a division gives you a much better overall impression of how the division's doing than written status reports from the division heads.
There's also the usual plethora of meeting rooms scattered around the place; when we first moved in in 2009 we had a competition to name them all. We've got Afoxalypse A & B, Seagulls A & B, Traffic Jam, Thinking Hats, Camelids A & B, Horses, etc. All the meeting rooms have pictures on the walls corresponding to their theme, which adds a nice bit of individuality to otherwise fairly drab meeting rooms. Generally, any meeting room can be booked by anyone at any time, although some groups have priority in certain rooms (Camelids B is used a lot for UX testing, the Interview Room is used for, well, interviews).
And, as you can see from the video, each area has various pictures, post-its, notes, signs, on the walls to try and stop it being a dull office space. Yes, it's still an office, but it's designed to be as interesting and as individual as possible.