Tower Heist is coming out on DVD and Blu-ray from the 25th April, in the lead up to its release we were lucky enough to have a chat with the film's director, Brett Ratner.

You have a very tight narrative in Tower Heist, but you're dealing with a talentedensemble cast. How fluid do you have to be as a director in order to deal with unexpected twists and turns on the set?

There's no improvisation on this movie, except for one scene when Gabourey's showingEddie how to open the safe. There was really no dialogue there, so I whispered that she should "Flirt with Eddie." She did, and he stayed in character, and it turned into this five-minute scene which was hysterical. Most of it is on the DVD. Nearly all of the actors stuck to the pages which is what they wanted to do because the script was so good. There wassome improvising that I would ask for, of course, from Eddie. I always wanted him toimprovise but he really loved the script so much he wanted to stick to it. Sometimes when you improvise it works, but sometimes it's just too long. What is most important to me isthe pace and the energy of the film.

Ben and Eddie did some stunts involving suspension. When their adrenaline is pumping in certain instances, how do you get them to maintain their enthusiasm when they'renervous about what's going on around them?

It is difficult but it is my job to keep everyone's energy up. The actors are going into the trailer, reading a magazine and hanging out, and I try to keep the energy and the pace on setup. I have to be enthusiastic the whole time. When they go to the trailer they get relaxed,and I have to get them excited about it. Their adrenaline was definitely pumping when they were in that car hanging off the side of the building. They weren't 65 stories up; we had onlybuilt four stories of the building on stage, so we still had them suspended vertically off theside of the building. I don't think they were really very happy about that.

Were they swinging in that scene where they were hanging of the building too?

Yes and as you can imagine, swinging is very nauseating.

When they shot the original chase sequence for The French Connection, they probably bent the law a bit. What were you able to get away with trying to reproduce that?

I wanted to shoot a scene under the train, and that was my little homage to it. Therewas one shot that I couldn't get that I had wanted to get, and it is probably the shot that he stole, which I was upset about. I wanted to buy the shot right out of the movie, and Icouldn't get it. We pretty much go by the book and push the limit of what we can do. Wedon't ever want to hurt anybody, but it’s fun doing action sequences.

What made pairing Eddie Murphy with Ben Stiller so perfect for you?

I think both actors had not done a movie like this before. They'd never worked together, and their chemistry was really dependent upon the movie gods. I had no idea if they wereactually going to work well, but when I first saw the first frame of that car scene, I said thismovie is going to work because they're so different. That is what really makes a great team, especially on screen. When you have two actors from completely different walks of life theirchemistry works. It is so much better than having two actors that are so similar, because it'shard to differentiate each character.

What did you think of Gabourey Sidibe's performance and her comedic talents in TowerHeist?

I hired Gabby from Precious, and she blew me away. She stood toe to toe with Eddie Murphy and was as funny as him. Her timing, her delivery, everything she did was great. Iwas completely blown away. I think she has a huge career ahead of her, and she's going tohave so many movies under her belt. She's so young still and has so much more to do. I'm really excited to follow her career.