Bit late to the discussion but wanted to comment.
All the above advice and comments are excellent and it looks like you've made your decision to GO, which is awesome as it something you'll never regret and you can now fill your days dreaming and planning, one of the best parts of travelling IMO.
I can put a different perspective on things though as we've only just returned back from 14 months away travelling as a young family. We have a house here in the UK that we rented out while we were away and we stored some stuff in a rented Garage next to my parents house too. Just some personal bits and bobs and a couple of bits of furniture we didn't want to part with. The main reason for getting the garage was to store a car, a classic Mini, that we'd never want to part with.
So... now we're back and when I read your original post I thought "don't sell the house". I understand your reasons, you need to do that to raise the capital to travel, at the moment it's all locked up in the house. Clearly I have no clue as to your financial circumstances but have you considered remortgaging, releasing all the capital you think you'll need and then renting it out to cover the mortgage? It doesnt have to be a buy to let mortgage, a lot of lenders will provide a 'permission to let' (for a fee of course) on residential mortgages.
I just know I wouldn't be happy now if we'd sold, whereas I wouldn't of cared at the start. We're now waiting for the tenency to run out on our house before we can move back in and I love the fact that I'm moving back into my home, a home I loved. If we had sold I can't imagine now having to go through all the hassle of getting back on the property ladder and looking at the rental market, it's staggering how much that's gone up (bonus for us of course, as we were renting ours out).
As for storage, I actually wish we'd kept more stuff. We now have to buy all our big furniture and white goods again, which we'll undoubtedly get second hand (so we can spend money on other things like more travel) but will still cost a sizeable sum.
Practically, storing a car is obviously quite hard, but my Dad ensured it was MOT'd before we returned so the day after we got back I insured and taxed it and we were mobile, within a day of returning. It's the small things that make the difference but after the first time we travelled we didn't have a car for weeks when we got back and it felt like we'd had our wings clipped, unable to roam and explore which was part of everyday life while away. clearly this doesnt apply if you live in a large metropolitan area but we live somewhere quite rural where public transport is terrible so we NEED a car.
Anyway, this post is getting quite long... I'll follow your blog and look forward to seeing where your journey takes you.
Mike Reply to this