Theatres outside London like to produce shows that appeal to their local communities. Inside London, where cultural attitudes are strangely warped, theatres are happy to disregard the neighbourhoods they serve, and they show little interest in the lives of their customers. But the Royal Court Theatre and Hampstead Theatre have both chosen to stage shows that feature characters who live nearby.

Mates in Chelsea, at the Royal Court, stars a bone-idle superbrat, Tuggy, whose inheritance is threatened when his snooty mother (who is brilliantly played by Fenella Woolgar) decides to flog the family castle in Northumbria. An offer is received from a Russian billionaire, Oleg, and Tuggy promptly has a meltdown.

After an elaborate farce, the play ought to peter out. But it peters on instead

He tells his girlfriend, Finty, that he plans to ruin the sale by visiting the castle disguised as the Russian buyer. Finty, unbeknownst to Tuggy, does exactly the same thing. And a third friend, Charlton, adds to the confusion by posing as yet another Russian speculator. The three bidders, each unaware of the others’ presence, are joined by the real Oleg, who hasn’t a clue what’s going on.

This elaborate farce develops very amusingly, with a lot of mix-ups and misunderstandings, but the fun doesn’t last very long. After 20 minutes, the scene descends into a confused series of fire-bombings, gunshots and executions. After that, the play ought to peter out. But it peters on instead. There’s a dream sequence, a rescue by an emergency helicopter, a state-of-the-nation rant about the ills of modern life and a chorus of battle-hymns once sung by Stalin’s troops. What’s all that about? No idea.

Anyone from Chelsea hoping to see their life represented on stage will be disappointed. The characters speak in silly, antiquated accents, rhyming ‘happy’ with ‘preppy’ and pronouncing ‘about’ as ‘a bite’. Tuggy’s mansion in SW3 is managed by a flippant housekeeper from Sheffield named Mrs Hanratty, who greets the arrival of each new guest by roaring out their name and title, as if she were the toast-master at a club dinner. But no one would ask their staff to behave like that.

The writer, Rory Mullarkey, has raised expectations too high by speaking of his admiration for Oscar Wilde and P.G. Wodehouse. Tuggy’s mum, a Lady Bracknell replica, delivers two or three decent gags. She refers to ‘socialism’ as a curse word, and when she’s asked about her alleged membership of the Tory party, she says: ‘I don’t donate money to left-wing pressure groups.’ Good stuff, but hardly worth leaving the house for. Mullarkey needs help editing his speeches and bringing his scenes to a conclusion more quickly, but no one at the Royal Court knows how to advise him. This is an amusing little playlet buried in 150 minutes of rhetoric.

At Hampstead, Nineteen Gardens is a tug-of-love melodrama about John, a handsome millionaire from NW3, and a Polish cleaner, Aga. Although she’s named after an unbudgeable piece of kitchen equipment, Aga is a slim, sexy blonde whom John delightedly seduces. Their one-night stand develops into a dangerous romance which John conceals from his wife and kids.

The details of the story are told in reverse which makes the play enjoyable to watch, and the elegant, minimalist design by Sarah Beaton gives it a chic, continental feel. It could be a new version of Yasmina Reza’s classic hit, Art.

As the story progresses, John becomes more caddish and heartless. He tells Aga that he continued to sleep with his wife throughout their affair even though his amorous thoughts were clearly elsewhere. ‘She lay as still as a starfish,’ he says, rather indelicately, ‘and I galloped through her body hoping to find yours.’

Aga, meanwhile, has found a new partner and raised a couple of brats in a poky little apartment. Then the bombshell arrives. She demands money from John and threatens to blab to his wife about their fling and destroy his family. Aga gets very picky over the terms of the pay-off and she starts to flip through property websites looking for luxury homes in Alexandra Park. At this point John seems to be snookered and his attempts to outsmart Aga seem a little obvious.

The rest of the plot unfolds very rapidly and chaotically. The script, which is written by an eastern European migrant, feels grounded in real experience but it doesn’t know what register to aim for. Is it a frivolous comedy of manners about rich Londoners and their uppity servants? Or is it a psychological thriller featuring an impotent skivvy who challenges the power of an arrogant, preening overlord?

It’s not funny enough to be a comedy and not quite gripping enough to be a thriller. If you live within walking distance of the theatre you’ll find this a pleasant way to spend an hour. Pilgrims from further afield are unlikely to make the trek.