The chalet-hotel is in a grey area. Is it an overgrown chalet or a hotel with a chummy atmosphere?

We all know what constitutes a hotel, and most of us know what constitutes a catered chalet. But the chalet-hotel is increasingly a grey area; it can be an overgrown chalet, or it can be more of a hotel with a chummy, house-party atmosphere. On the one hand, this leads to a wider choice of styles of holiday. On the other, it means you need to be careful to pick the one that is right for you.

The basics are clear enough. A chalet-hotel (or a club chalet, or a jumbo chalet) is a building that is big enough to be a hotel, run by a British tour operator along traditional catered chalet lines, with British staff. Because in many cases the building has indeed been run as a hotel in the past, you get some benefits not normally associated with chalets - in particular, bedrooms of a decent size, with en suite bathrooms. Because it's big, the inmates eat at a number of separate tables, rather than in the traditional refectory style - though who you get to chat to is still normally pot luck. There is often a bar, which may or may not be open to non-residents; indeed, some of Mark Warner's chalet-hotels in Verbier and Val d'Isere, especially, are major hubs of the nightlife.

A year or two back, I might have risked a further generalisation: that chalet-hotels were neither stylish nor luxurious, being based on rather cheerless old hotels that were in need of investment to prolong their active life. Not so now.

My recent review of the best chalets in the key resorts of Meribel, Courchevel and Val d'Isere included one - FlexiSki's 20-bed Lodge Nogentil - that retains all the style and warmth of the charming little French-run hotel that until this season it was. This place departs more than most from chalet norms. The bedrooms are excellent, while sitting space downstairs is at a premium. Dinner is served when you want it (within certain limits); wine is not included in the price, but there is a range of reasonably priced bottles. The place still operates as a hotel, so if you're lucky you'll find not all the guests are British.

A few weeks back, I discovered another non-standard chalet-hotel - again, still formally registered as a hotel - but one that is a lot bigger (more than 70 beds), and a lot cheaper (less than pounds 500 except in half-term week). It is the Cristallo, in Courmayeur, offered as a British-run chalet-hotel for the first time this winter by Bladon Lines.

The Cristallo is a three-star hotel, renovated with great style only a couple of years ago. Heavily carved wooden doors lead to mostly spacious bedrooms, well equipped with glossy bathrooms in classic Italian style. The first-floor sitting room (with bar) is atmospheric and welcoming. And the position is pretty well unbeatable. It is just off the pedestrianised Via Roma at the captivating heart of Courmayeur, close to some of the very best bars, and a tolerable stroll from the cable-car that is the start and finish of the skiing day in this emphatically not purpose-built resort.

I left the enveloping charm of Courmayeur and the Cristallo for the brutality of Tignes. Happily, the chalet-hotel where I was accommodated there is traditional in style: Ski Olympic's brand-new 42-bed chalet Rosset has the pitched roof that French resort architects have been forced to revert to, and a bright, pleasant interior. Having been built as a chalet rather than a hotel, the Rosset does not have notably spacious bedrooms. Ski Olympic describes them as "small to medium in size"; my colleague and I were grateful to collapse in a small one, but on holiday I'd go to some lengths to bag a medium one.