Have you ever considered doing a house-swap? This involves literally swapping your house for some other private family home within the UK or overseas. It means that the accommodation part of your holiday is free and you have only to cover travel, food and entertainment costs. Sounds good and it is, BUT it is not hassle-free as obviously you must leave both your own and your swap's house in immaculate order. Well worth a thought though.
Green Theme International Home Exchange agency was established in 1989 just as the debate about consideration for the environment and the need for sustainable tourism was just beginning. GTI suggest you 'protect your environment by using existing resources to the full, thus reducing the ever increasing demand for mass tourism development'.
This is a USA based website but has exchange listings worldwide. Click on a country where you want to go, Click on an interesting Listing and then send a privacy protected email to that Listing directly from the site.
This is a UK based home-swap website.
Homelink is an international house-swap company with local organisers in 27 countries and has been in operation for quite a long time.