Hi Mikkel Both are 'natural', as people use either without really making any distinction. There is a really long complicated explanation of the grammar rules involved, if you need it, on another discussion board - see http://ell.stackexchange.com/questions/14290/five-minute-or-minutes Chris

I'm not 100% sure about the grammar but my instinct is it should be written thus: five minutes' walk. It is a completely natural thing to say in speech without the article.

You can say "a five-minute walk" or "five minutes' walk". Note the use of the hyphen in the first and the apostrophe in the second. As usual with complex nouns, there's also the third alternative - the 'of' construction. We use this if we want to put in some kind of modifier e.g. "It's a walk of only about five minutes." You could add an 'a' to "five minutes' walk", but I can't see any grammatical justification for it. Here's why: You need an article in the first, because 'five-minute' is an adjective - just as you'd say 'a brown-eyed girl', you need to say 'a five-minute walk'. We don't need an article before the genitive form, though. Think of "Mum's car", "China's economy" or "Wednesday's meeting". The use of the genitive case makes this a definite noun, so it strikes me as wrong to use an indefinite article. In the overall scheme of crimes against humanity, there are worse things to worry about, but..

In my part of the world we would write: a 5 minute walk

Although it's not very important, the usual rule is that small whole numbers should be spelled out in full. Thus, you would write out "five" rather than using the numeral "5." Notice that Su.Ki. and Paul did this even though they didn't mention it. I agree that you need the hyphen in "five-minute walk" and, very definitely, the apostrophe in "five minutes' walk." In the US, both are correct, both are used, neither sounds odd. However, "a five-minute walk" would be more common. Oddly enough, I don't feel this is true for "hours." I think "it's five hours' drive" and "its a five-hour drive" are equally common.