Personally, I don’t know of anything like that to rent – at least not to live in for any length of time. Prefabricated homes are out there, but are expensive to buy and I would suggest this precludes them as a sensible option.

I think you’re right and a static caravan is the answer.  Obviously, I’ve not seen the plot in question, but I’d have thought a small touring caravan would get through that sort of gap. However, living in a Sprite Alpine or the like with two young children for several months would not be much fun for any of you.

If the issue is that you can’t get a static caravan down the drive and into the garden, I would think laterally and go over the top of the trees by using a long-reach crane to gain access your garden. Cranes of this size are not cheap to hire, but the work could be done in half a day and will be far cheaper than buying a prefabricated temporary home.

If you are in a position to buy a caravan rather than rent, you can sell it on at the end of the build which would offset some of the costs involved.

Mike Hardwick