You could try the Canary Islands, which is priced as out-of-season in the summer, although it is still lovely and hot. Princesa Yaiza hotel has rooms with a mini kitchen, so you can self-cater, as well as a kids club and teens club to suit both your kids.
See http://www.totstoo.com/hotel_princesa-yaiza-suite-hotel

Another good choice would be Martinhal in Portugal, where you can have the freedom of self catering in a villa, but enjoy all the facilities of the hotel. There's a kid club, and all the teens meet up at the Blue Room, with table football and video games.
See http://www.totstoo.com/hotel_martinhal

Hope you find somewhere that you like!

get 14yr old to plan it??
we used to ski every year until 14yr old started complaining, so we got her to plan christmas and had a great trip to thailand. she wanted shopping and chilling and sunshine, and she got it, and the rest of us loved it!

The Alps in the summer is lovely, fun, etc... No beach, but lakes and rivers, with sand... Kids can to fun things like mountain bike, ride horses, hike, etc. Anyway, we find it a fantastic get away. Oh, and because it isn't really a popular summer destination.. it is very reasonable! Good Luck.

HI, check out my recent blog on Portgual's best kept secret, some great new family hotels, and amazing surroundings. http://wp.me/pQTLF-el If I can help, please do give me a call 0207 720 8484

Advice please. Have 2 kids 14y and 6y. (big age gap, hard to please all) Want a nice place in Europe (forget UK , I need some sun) for summer for 2 weeks. 14 y old refusing French campsite for 3rd year in a row ( fair point). Need other children, lively enough for 14y old but quiet enough (yes, I am middle aged!) so my husband and I can rest/ read books/sunbathe/ enjoy a glass of wine/ sleep without being near a rank club 18-30 zone. Have done Club med in past,great but are pricey. I don't mind self catering in complex with others with shared facilities. Near beach wld be ideal. You know what I mean.... I've run out of ideas! Need advice.it's my summer holiday- I want to get it right.
Thanks.