Underwater Tank Statistics:
- It is 8 meters deep.
- 20m x 20m with a viewing chamber
- It took approximately three months and 50 construction workers to build
- It is the largest underwater filming tank in Europe
- It holds half a million gallons of water and can be filtered in three hours.
- The water is only 50% chlorinated, which allows actors to remove goggles during filming without the water irritating their eyes.
- Grimmauld Place is the ancestral home of Sirius Black's family.
- All rooms in the set were built separately but on the same stage
- The kitchen table was made specially and is 20 feet long and 2 feet, 9 inches wide.
- All of the china in the kitchen was bought from markets, auctions and second-hand dealers. The Black Family crest, 'The Honorable House of Black," was created by the graphics dept. and added to the crockery.
- The bedroom is on the second floor of the house and is where Sirius" mother would have kept her jewelry, hat boxes and collection of fans. The furniture in the bedroom (beds, wardrobe, and dressing table) was bought at auction.
- There is a painting of the bedroom on the bedroom wall, with unmade beds
- The black silk eiderdowns on the beds were made for the film.
- The fabric used on the hall and stairwell walls was made from 350 meters of dark grey silk bought in from India and then screen-printed in gold. The same pattern was used on the curtains in the drawing room.
- In the hallway and staircase, the elf heads in glass domes were made by the creature effects department.
- In the hallway there is a giant troll"s foot umbrella stand. This is a mold of the troll"s foot from the first movie.