These aren't new but having just come across them again recently I thought I'd mention them. Coleman make a number of tents that are designed with destachable extensions so that you can have a small tent sometimes and extend it to make a bigger tent when required. I can see that this would also be useful firstly if you go camping with differing numbers of people, for example sometimes the tenagers tag along sometimes they don't. It would also be useful if you wanted to have a smaller tent that's faster and easier to erect for a weekend stay but then be able to have the extra space if you were camping for a longer period.

The Coleman Modulus range have a detachable side extension which doubles the sleeping berth count for each tent in the range, the Modulus 4 for example goes from a 2 berth to a 4 berth with the extension added. Of course you don't have to use the extra space sleeping you could use it for additional storage or additional living space.

The Coleman Evolva takes the idea one step further with a central hub on to which you can attach 3 different types of 'annexe'. The Sleeping Annexe adds additional sleeping space as you'd expect, the Chef's Annexe adds space that can be used for general use (not only as a kitchen area as the name suggests). The last type is the Link Annexe which allows you to link 2 of the hubs together, allowing you to create palatial sized tents if you so wish.

We have a removable inner tent in our big tunnel tent which is useful, giving us extra living space when it's not required and I can see the advantages of the Modulus approach but I am not so sure about the Evolva, I can't really see who would use such a set up, unless you have a very specific need for a particular tent configuration.