Last Night's Viewing: The Manor Reborn, BBC1<br></br>Living with the Amish, Channel 4

I'm Penelope Keith and it strikes me that I might have bitten off more than I can chew," said Audrey fforbes-Hamilton at the beginning of The Manor Reborn, a new series in which the National Trust has outsourced the refurbishment of one of its properties to a team from the BBC, in return (one assumes) for a bit of much needed publicity.

The implication was that this was her project and that it was just beginning to dawn on her that she might have got carried away by her fabled enthusiasm for ancient buildings. One has got used to the idea that telly rarely tells the whole truth in its reframing of reality, of course, but that opening remark would have been much closer to the facts if she'd said something like the following: "I'm Penelope Keith, and the only reason I'm here is because the producer worked his way back from a cutesy title and I didn't have anything better on the books at the time." This was, someone else told us, "the ultimate stately home challenge". It was also an object lesson in the ersatz tension-building and the low-level mendacity of quite a lot of popular television these days.

I'm not talking whoppers here. It probably doesn't really matter that Keith and her co-presenter, Paul Martin ("Mr Flog It! himself"), pulled up in front of Avebury Manor simultaneously and pretended to greet each other spontaneously, as if it had happened by chance. Viewers know perfectly well that it's a fib, and just a bit of television grammar. But, perhaps because the programme itself was much concerned with the distinction between reproduction and the real thing, between authenticity and pastiche, it somehow got under my skin here. Why is it that so many stock devices of television storytelling are transparently bogus? And shouldn't it grate on us a bit when the stock exaggeration of so much television commentary edges towards a direct untruth? Here, for example, we were told that the interior designer Russell Sage would be asking his regular suppliers to donate materials and services for free: "With a limited cash budget," the voiceover continued, "if he doesn't persuade them to help, the whole project will fail." Really? Not just a bit of trimming back on the budget here and there? Not just the sort of compromise every project like this involves?

But it has to be life or death, because it's assumed that we won't be interested otherwise. And that, in the end, is far more infuriating than the clichéd fictions of "challenge" and ticking deadlines. The Manor Reborn involves all sorts of intriguing questions, about the best way to sustain life in historic buildings and how easy it is for restoration to tip over into Disneyfication. It also looks as if it might offer you one of television's most captivating sights – highly skilled people doing the thing they're skilled at. But so far all the stuff that might actually enlarge your knowledge or genuinely surprise you has taken second place to the sort of synthetic cliffhangers we've seen a hundred times before. Honestly, you don't have to tie a maiden to the rail-tracks to make us watch. And even if you do, the maiden doesn't have to come from a popular sitcom. Just show us the most interesting things you find. And try to cut down on the storytelling.

It looked as if Jonathan, who played host in Living with the Amish, might have been told a lie too. "All we know is that these teenagers have been handpicked to represent the best of British youth," he said before his guests arrived. Poor trusting Jonathan, I thought. But then, instead of sulking and tantrums, we got polite engagement and some genuinely moving emotional connections. The teenagers glimpsed a life beyond the tyranny of cool and the tedium of self-indulgence, and they admired it. Contrived situation, yes, but the truth too.