What can you tell us about Grand Tour Of Europe?
"It's taken us about six months to film it, all around Europe. A lot in cars and a lot on the train. I wouldn't say [I did it] exactly how the grand tourists of the 17th century did! They faced all kinds of dangers: disease, death, sexually transmitted diseases - which was of course incurable then, despite people rubbing mercury into themselves."
What made you do it? Was it just an excuse to tour Europe?
"Yeah! You know me - I spend my time talking about architecture, buildings and construction, and I'm a big green advocate. It's great and lovely, but 25 years ago I was studying history of architecture so for me, this is a return to source really. I lived in Italy for about a year and a half so it's a joy to go back and revel - innocently - in these amazing places."
I hear that you visited some drinking dens as well. Are we going to see Kevin McCloud going off the rails?
"I can hold my drink! I didn't go off the rails, but I do like wine. We did drink quite a lot, but nothing could have matched the consumption of the 18th century aristocrats. These young boys in their early twenties going around Europe, drinking six, seven, eight bottles of wine a day - each! Can you believe that? I could only manage five."
Grand Designs is still performing well. Why do you think that is?
"It's amazing, isn't it? I think, first of all, it's not a property show, so we don't talk about money that much. For that reason, it's weathered the recession very well. That's why it endures - because it's not a format programme. We don't go round to somebody's house and clean their dog for them. We watch real people in the real world. Consequently, there's a powerful narrative about that. When you look at it, Grand Designs is good, old-fashioned storytelling, it's documentary making, and it's very traditional."
Has the recession affected the series at all?
"It has affected filming in that what has happened is projects tend to be slower. So instead of taking a year, they now take a year and a half. But we're still getting projects in. And for many of the projects we're filming at the moment, the finance was sorted for them years ago. For the ones that are now coming on, let me put it this way: it's always going to be a tiny minority of people who do this so we've always had difficulty finding great projects."
Are you always honest? What happens if you see a Grand Design that you don't like?
"I used to think that we should always try to celebrate stuff, but I am getting too old and too grumpy now that I just think, 'sod it!' and say what I think. There is a distinction between slagging people off for their taste - which I don't think is acceptable - and judging the project against its own merits. For me, the two benchmarks are the quality of design and the quality of execution."
How long do you think it can go for?
"We've got a show next year and we're filming for the following year, so as long as people keep watching it, we will keep making it. I'm hoping I might make my retirement from it! We'll see how we go. I'm never bored: boredom isn't a word I use. I get tired with all the travel and I get frustrated and I'm in a foul mood in the mornings, but within about 10 minutes, that's evaporated. At the end of the filming day, I'm absolutely gunning for it."
Kevin McCloud's Grand Tour Of Europe begins Sunday, September 20 at 9pm on Channel 4.