Last night's viewing - Elementary, Sky Living; George Clarke's Amazing Spaces, Channel 4

An enigma has been solved in a most ingenious way – the solver cutting through the preconceptions of fuzzier minds and delivering the solution with a flourish. What was inexplicable has been unfolded and smoothed flat. Impossible knots have been deftly loosed and unravelled.

Then, having watched all this, someone else comes along a little while later and solves the same crime all over again, using an almost identical method but with less flair. If they then turned and hoped for a round of applause from the onlookers, the very least you might accuse them of was undue optimism. And yet, for British viewers, that's exactly what Elementary is trying to do. Following in the wake of Steven Moffat and Mark Gatiss's witty and affectionate updating of the Sherlock Holmes stories, it offers Jonny Lee Miller as a modern version of Conan Doyle's pioneering detective and – purists are advised to take a seat here – Lucy Liu as Dr Joan Watson.

Without the precedent of Sherlock and Benedict Cumberbatch and Martin Freeman's excellent double act, they might have got away with it. Elementary isn't terrible, unless you are actually a Conan Doyle purist and can't bear any kind of tinkering with the object of your devotion. But it's also pretty ordinary. Where Sherlock saw that a great classic might be refreshed by time travel, in a way that honoured and threw light on its essential qualities, Elementary is actually a solution to a different kind of problem altogether. It isn't really a new kind of Sherlock. It's a new kind of misfit detective, one of the more overworked tropes of American detective fiction. And given Conan Doyle's Sherlock was the model for pretty much every outsider oddball detective since, there's a strange circularity to the whole thing.

Miller's Sherlock has just emerged from rehab, breaking out on the very day he's due to be released because he's "bored". Dr Joan has been hired as a kind of addict nanny, paid by Sherlock's wealthy father to make sure that he sticks to the programme. As she arrives at the Brooklyn brownstone where Sherlock lives, a tattooed hooker is leaving. "Did she get you high?"asks Watson. "About six feet," replies Sherlock, pointing to the bondage handcuffs dangling from a library ladder, and explaining that though he doesn't much care for sex he has to feed the appetite from time to time to avoid being distracted. We get our first hint of what may come to be a tiresome element of unresolved sexual tension between the two. Then they get their first crime – not a cleverly reworked version of one of Conan Doyle's plots but a fairly straightforward Hollywood mystery.

Sherlock here has the disdainful mien and rapidity of speech we know and love. He has the sudden darting leap to an unexpected perception. He has a rather nifty microscope attachment on his iPhone and isn't above using Google ("Not everything is deducible"). But his solutions appear to leave a troubling gap between raw evidence and final conclusion. He doesn't deduce, so much as make reckless extrapolations that then conveniently turn out to be true, which isn't anything like as satisfying. He also talks in a way that sometimes seems jarringly wrong: "I don't see him having the berries to take another life," he says at one point when he dismisses a suspect. The berries? Did they just lose their nerve at having him say "balls"? Moffat and Gatiss have nothing to fear – there's no threat here.

Ingenuity of a different kind is showcased in George Clarke's Amazing Spaces, which is essentially Grand Designs on a hundredth of the budget. The designs, that is, not the programme. Episode one featured a couple who'd turned an old coach into a unique holiday let and a woman who'd carved a rather nice south London pied-à-terre out of some Victorian public toilets for just £65,000. It's neat, modest and perfectly formed.