The film's title is based upon the English saying, repeatedly referred to in the film, "a man's home is his castle". Its humour plays on the national self image, most notably the concept of working-class Australians and their place in modern Australia.
The Kerrigan home, in the outer Melbourne blue-collar suburb of Coolaroo, is filled with love as well as pride in their modest lifestyle, but their happiness is threatened when developers attempt the compulsory acquisition of their house to expand the neighbouring airport.
The Kerrigan house is built in a largely undeveloped housing tract, on a toxic landfill, and directly adjacent to an airport runway. Despite all this, sweet-natured family patriarch Darryl (Michael Caton) believes that he lives in the lap of luxury. Blissfully unaware of his family's lack of style or sophistication, he busies himself by driving a tow truck, racing greyhounds, and constantly adding tacky renovations to the house. The rest of the Kerrigan clan shares and supports his enthusiasm in every way.
One day, a property valuer arrives to inspect the house. Though he has no wish to sell, Darryl points out all the features of the property, believing they'll add value to the appraisal. A few weeks later, he receives a letter informing him of the compulsory acquisition of his house for the sum of $70,000. His neighbours (elderly Jack, divorcee Yvonne, and Farouk and Tabulah, recent immigrants from Lebanon) all receive similar notices. Believing on common principle that the government cannot evict him unwillingly from his treasured home, Darryl attempts to fight the eviction. Agents from the airport try to bribe and bully the family into giving up, but their actions only stiffen the Kerrigans' resolve. Darryl hires an incompetent lawyer acquaintance, Dennis Denuto (Tiriel Mora), but Dennis's meagre argument that the eviction goes against "the vibe" of the Constitution does not go well in court. While awaiting the court's final decision, Darryl makes pleasant small talk with a man whom he meets outside the courthouse, Lawrence Hammill (Bud Tingwell), who has come to watch his son (a barrister) perform in court. The court rejects the family's appeal and gives them two weeks to vacate. The purchase price for the home is scarcely enough to cover a small apartment. Dejected in defeat, the family begins to pack.
A new breath of hope comes with the surprise arrival of Lawrence, who reveals himself as a retired Queen's Counsel. Lawrence has taken an interest in the Kerrigans' case and offers to argue before the High Court of Australia on their behalf, gratis. Lawrence makes a persuasive case that the Kerrigans have the right to just terms of compensation for acquisition of property under Section 51(xxxi) of the Australian Constitution. He closes by paraphrasing Darryl's own comments that his house is more than just a structure of bricks and mortar, but a home built with love and shared memories. The court rules in favour of the Kerrigans, and their case becomes a landmark precedent on the subject. An epilogue shows that the Kerrigans continue to prosper happily, and Lawrence becomes a lasting friend of the family.Michael Caton as Darryl Kerrigan, the patriarch of the family
Anne Tenney as Sal Kerrigan, his loving wife
Stephen Curry as Dale Kerrigan, the youngest son, digger of holes, and narrator of the film
Sophie Lee as Tracey Petropoulous (née Kerrigan), the family's only daughter, a newlywed hair dresser
Eric Bana as Con Petropoulous, Tracey's new husband, an accountant and amateur kickboxer
Anthony Simcoe as Steve Kerrigan, the second oldest son and an apprentice mechanic
Wayne Hope as Wayne Kerrigan, the black sheep, who is serving time for armed robbery but is loved by his family regardless
Tiriel Mora as Dennis Denuto, a bumbling small-time lawyer who previously failed to defend Wayne on his charge
Costas Kilias as Farouk, the Kerrigans' neighbour
Charles 'Bud' Tingwell as Lawrence Hammill QC, a retired barrister who comes to the Kerrigans' aid by defending them pro bono
John Flaus as Sgt. Kennedy, a local police officer
Tony Martin as Adam Hammill, Lawrence's son (brief, mostly non-speaking cameo)
Ian Ross appears as himself, a Channel Nine newsreader
The film refers to the land rights movement of the Australian Aborigines, with Darryl Kerrigan drawing an explicit parallel between his struggle and theirs. It also draws on one of the few rights protected in the Australian Constitution for subject matter, the right to just terms compensation for acquisition of property under s51(xxxi). Also interspersed in the film are many references to famous Australian Constitutional Law Cases, such as Mabo and the Tasmanian Dams Case. The film also deals with section 109 of the Constitution which provides that in the case of an inconsistency between Federal and State law, the Federal law shall prevail to the extent of the inconsistency.
For the purpose of the drama, some of the relevant legal principles are simplified. For example, the law relating to compulsory acquisition can be complicated and raises more questions than are noted in the film. Section 51 (xxxi) of the Commonwealth Constitution only applies to acquisitions by the Commonwealth, not the States, and the latter is more likely to compulsorily acquire property. Similarly, in contrast to Kerrigan's idea that the value he places on his own home cannot be bought, the law regularly places a monetary value on intangible human values.
According to Santo Cilauro, the film took five weeks from original inception to final cut. The movie was written in two weeks, shot in ten days and taken to rough cut in two weeks.
The Castle was filmed mostly in Melbourne, Victoria. The external shots of the Kerrigan household were shot at 3 Dagonet St, Strathmore, and airport footage was shot at Essendon Airport and Melbourne Airport. Location shots of Brunswick feature in the film, including Brunswick Town Hall and Rocky Porcino Pharmacy at 720 Sydney Rd (Dennis's office). Melbourne's 200 Queen Street and the Supreme Court of Victoria are featured along with the High Court of Australia in Canberra. Some of the film is set in Bonnie Doon, and a very small portion of it was shot there.
The name Kerrigan was chosen for the family so that tow trucks for the film could be borrowed from an existing Melbourne tow-truck company with that name. The company still operates today.
In January 2011, 3491 Maintongoon Road, Bonnie Doon was listed for sale. The property appeared in the film as the Kerrigan family holiday house. The property's real estate agent reported that many people called and after requesting the vendor's asking price, replied with a quote from the movie: "Tell him he's dreamin'."
In the US version, there were several minor changes to dialogue. "Rissole" was changed to "meatloaf", "two-stroke" was changed to "diesel", references to the Australian TV show Hey Hey It's Saturday were changed to the more generic Funniest Home Videos (which existed in both markets), and the brand names of the various cars in the driveway were changed from uniquely Australian cars like the Camira, to ones sold in both countries like the Corolla.
The Australian TV version for "before-8:30pm screening" has scenes of explicit language either completely cut or, where possible, masked by aircraft noises or redubbed when lip movements are not visible. When broadcast after 8:30pm, all explicit language is intact.
The Castle grossed A$10,326,428 at the box office in Australia, over 13 times its A$750,000 budget.
US rights were bought by Miramax for a rumoured $6 million.
The Castle received positive reviews from critics. It retains a "Fresh" 88% rating from review-aggregation website Rotten Tomatoes, based on 34 reviews.
Roger Ebert gave the film 3 stars out of 4, calling it "one of those comic treasures like "The Full Monty" and "Waking Ned Devine" that shows its characters in the full bloom of glorious eccentricity".
In 2011, Time Out London named it the 25th-greatest comedy film of all time.
The Castle can be seen as a social study on the lives and aspirations of the inhabitants of suburban Australia. The central character, Darryl Kerrigan, ties into the stereotypical depiction of an "Aussie battler", a man who will protect and serve his family through bold and sometimes ruthless assertion. The Aussie battler will at times face challenges or adversity, often in the face of oppressive government or economic hardship. Kerrigan, and to a lesser extent his wife and children, are committed to their pursuit of the Australian Dream, a concept considered somewhat outdated.
The Castle, like many other Australian television shows and films, portrays the average Australian as "un-cultured" or ignorant of culture beyond what is filtered down through the masses (on mainstream television or in tabloid journalism), and to a lesser extent the restrictions failing to explore a city beyond one's suburbs impose on families as far as exposure to arts or entertainment. A recurring gag in the film has Darryl ask his wife, Sal, what she has cooked, to which she frequently replies with something as simple as rissoles (a minced meat dish), sponge cake or ice cream. This references the stereotype that Australian cuisine tends to be unsophisticated, something that is less prevalent now than it was in the early to mid 1990s.