Note that I said “harder”, not “impossible”. Clearly, there are plenty of well-known horror films that are set in this country, and some actually ignore or deal with the problems I’m going to mention. However, it remains the case that there are certain barriers to making a film set in the UK believably scary, and if a film-maker want to by-pass them, they’ll have to work harder at it.
1. The smaller the house, the less easy it is to make it scary
Although I’m sure not all Americans live in whacking great “ranch-style” houses (and, of course, not all Britons live in small ones), if you see any house in a Hollywood movie, it will almost certainly be much bigger than your average British one, even if the owners are only supposed to be ordinary middle-class suburbanites. There are good practical reasons for that. The bigger the house, the easier it is to fit in your cast and film crew without things getting unpleasantly cramped.
But it is also the case that it is a lot easy to make a big house scary than a small one. It’s believable that the serial killer has got in and is hiding somewhere without being noticed, or that the terrified babysitter has run off to hide in a cupboard without it being completely obvious that she’s there. You can have long, tension-building POV shots, where the camera takes the place of the protagonist walking through the darkened hallway and up the stairs, where the monster may lurk. I live in a one-bedroom flat, and you can walk across it in a few seconds, with or without the lights on.
Try making that frightening.
2. The more remote the countryside, the more believable the threat
Much like space, the US is big. Very big. It has serious countryside. Rurality with attitude. Actual wilderness. You can hide away all sorts of menacing things in there and still keep it credible – inbred families of rednecks, aliens, werewolves, Satanic cults, Mormons. You also have quite a range of different types of habitat – mountains, deserts, large rivers, the Arctic, even (sort of) jungle (the Everglades isn’t a million miles off that). You can have your characters attacked by anacondas or giant alligators and it won’t look totally stupid (well, it probably will, but at least not because that animal just couldn’t live there).
In Britain, outside a few places like the Scottish Highlands, nothing is really more than a short drive from civilisation and the obvious question would always be – “Why don’t these monsters have people turning up on their door-step more or less every weekend?” And anything you throw at your characters has got to be believable as an inhabitant of either (a) farmland (b) woods, mostly not very big (c) mountains that at no point go much over 4000 feet (and that’s Ben Nevis) (d) rivers, mostly not very big and, well, that’s about it.
To be fair, the first of those is often a problem in the US as well, in spite of the space. Unfortunately, one of the popular movie solutions to that doesn’t really work either…
3. There isn’t really such a thing as a hick in a small country
Where your bad guy is stuck in the same place killing people on a regular basis, one way of justifying him never being caught is by showing that he’s a hick in league with other hicks, the “normal” locals, especially with authority figures like the local sheriff or mayor. Maybe blood is thicker than water, or they just want to make sure that only outsiders become victims. That turns up in the Texas Chainsaw Massacre films and the Wrong Turn films, to mention just two, and it works in a country where even small towns in the backwoods can have their own local government and police who aren’t really answerable to anyone outside the town.
Well, the UK isn’t one of those countries. Places that would be called towns in the US are just villages. The local government for the whole district is probably run out of a much larger town nearby and the local police might be responsible for one or several counties (or more – there’s only one police force for the whole of Scotland, for example). So you can’t really have the all-powerful local official who protects the local monster. And when very few people are really far away from towns or cities, it’s really difficult to do the whole “inbred hicks” trope anyway. It’s mostly inaccurate and insulting even in the American context, but you can still just about show it without breaking the audience’s suspension of disbelief.
4. Indian burial grounds don’t really exist in the UK
Unless your name is Pocahontas. This pretty much speaks for itself.
5. You can’t use convenient high school/college stereotypes to “characterise” your cast
An awful lot of bad Hollywood horror movies start out with a bunch of teenagers/twenty-somethings setting out somewhere to party, and then getting slaughtered in the process. Doing that allows you to rely on easy clichés from high school or college movies to let the audience know who they should hate or sympathise with and who’s likely to die. Any loud, obnoxious jocks/fratboys and bitchy cheerleaders are really unlikely to still be breathing by the end credits, for instance.
You could maybe do something similar in a British movie (a loud, drunk guy is a loud, drunk guy, after all). It wouldn’t be as easy, though, because the stereotypes aren’t nearly so well-established and a lot of the American institutions either don’t have British equivalents or only do to a limited extent. For instance, more or less the only school or university sporting event that arouses any national interest here is the Oxford v. Cambridge Boat Race (and, not coincidentally, that’s the best place to look for the sort of thinly-disguised professional “student” athlete that you find a lot in the US).
After all that, you might wonder how any British horror movies ever get made, but of course the sort of plots and characters I have mentioned aren’t the only possible ones for a horror movie. I have also deliberately avoided anything horror-related where the UK might actually make a superior setting to the US – haunted mansion stories, for instance, or anything that draws on history older than three or four hundred years ago. You might even see the difficulties I mention as advantages. After all, there are a lot of very bad films churned out that rely on all the things above.