We will be based in Brussels for 6 months, traveling a lot on short one or two night trips in W. Europe. I need a kitchen, to cope w. food allergies, and it can't be shared. Apartments (like those on VRBO might only rent by the week). What kind of equipment do apart-hotels have, and what chains have good coverage of W. European/Scandinavian countries? Any tips for booking this kind of accommodation?
I've stayed in several branches of Citadines, and usually been satisfied. I've also heard good reports of Appartcity. The only "tip" I can think of is that you can get good rates in advance, but also look out for shorter notice sales. Usually you get a hob (but not usually an oven) and the usual pans, crockery, cutlery and so forth. You don't usually get an oven (unless sometimes a microwave) or any powered food preparation equipment.
It is not true that you can only rent VRBO apartments by the week. They are individually owned and each owner has their own policy. Sometimes they will make exceptions too. I use VRBO and Homeaway to find apartments. I rented an apartment in Verona for 2 nights. It's worth a look!
Just to comment on some potential issues with apartments. I have never paid an additional cleaning fee. I don't choose to rent apartments with those charges. The only time I have paid a security deposit, I said I would only do it by giving my credit card number, as opposed to actual money or cashiers check. Yes, you have to agree on a time to meet the landlord, but that has never been an issue with us.
Robin, Two-night private apartments are not worth the hassle for such short rentals, I think. You best choice are hotels that have small kitchens. They usually cater for business travelers that are there on extended stays, or work out of home the whole week. Therefore, in bigger cities with business traffic like Milano, Wien, Frankfurt, Madrid they are always cheaper on weekends, sometimes deeply discounted. However, usually their location is not on the prime touristic areas but near some major CBD with good public transportation connections. Use sites like Booking.com and restrict the search to hotels with individual kitchen, and you will find them.
Wondering why an apartment is not worth two nights?? How is it different than two nights in any other kind of lodging?
If you try booking.com and look down the list of types of rooms, you'll find apartments. Tripadvisor also has places in many cities. As has already been mentioned, VRBO apartments can usually be rented for whatever period you and the owner agree on.
I believe what Andre means is that in addition to many private apartment rentals having minimum stay requirements (although, yes, these can sometimes be adjusted simply by asking the owner up front if they are willing to negotiate the number of nights), private rentals often tack on additional fees for things like security/damage deposits (refundable, but it's an additional up front out of pocket cost, none the less) and non-refundable cleaning fees to flip over the apartment because it must be cleaned between each guest. You're also dealing with owners that have to make arrangements to mail keys or meet you to get you a set of keys upon arrival (a pain if you are arriving very early or very late in the evening) and if there is a problem with the apartment, your short stay means you are kind of stuck with it as opposed to an aparthotel like Citadines which will simply shuffle you into another comparable unit or will have someone on call 24/7 to resolve the problem quickly. Aparthotels kitchens are equipped with just the basics for cooking - fridge, sink, knives, microwave, electric cooktop with a few sauté pans and cooking pots. A few may offer an actual oven. On a short 1 or 2 night stay, I would tend to use a kitchen in an aparthotel to stock some breakfast/lunch items and cold drinks. They are ok to cook something very simple like pasta for dinner if I really don't feel like going out to a restaurant. But I don't have severe food allergies so if you needed a fully stocked kitchen you will have to ask what is included (even with a private apartment rental as some are very well equipped and others sometimes are on par with an aparthotel so will limit what you can produce for meals).