What is the one sentence that makes Kevin McCloud shudder?

The longtime Grand Designs presenter says his heart sinks whenever he visits the owners of a promising new site and hears these fateful words.

Insights: Kevin McCloud

Has the novelty of being a British television icon for more than two decades ever worn thin? Honestly, I thought it would. When we started making Grand Designs in 1997, I thought we’d be watched by one surveyor and his dog. It wasn’t ever a massive hit but it’s a slow burner that has evolved as a series over time. And that’s why we’ve ended up here 25 years later.

Were you surprised by how beloved Grand Designs became in Australia? Well, I understand why the series works in the UK. In a weird way, it defines who we are as a nation. A British journalist once wrote about the show: “All Grand Designs is about is people going through hell so that at the end of it all they get a house that’s slightly nicer than yours.” I still don’t get why the series would be so successful in Australia.

Kevin McCloud

Is there a common thread between the two countries when it comes to architecture? Many of the problems we face are the same. There’s an absence of social housing and there’s population density problems. Across both countries I see the American influence of building the big house right to the edge of the block. Off camera, [host of Grand Designs Australia] Anthony Burke agreed you could shrink most of the projects we film by 30 per cent and the owners wouldn’t notice.

Presenting can be a tough gig. Have you had any clashes on Grand Designs? Some of the people we’ve filmed who are building their dream projects have pretty much joined a cult. It doesn’t matter what you say or how much you criticise them, they will always say no to you.

Are there any heartwarming characters that stand out? There was this odd couple I worked with on one season – Gregory, who was an architect, and his lighting designer wife Rebecca. I think because he was a designer he took my criticism quite personally and was almost petrified, but they always played it cool in front of me. Their place in Cornwall became one of the most beautiful buildings I’d ever been in.

What was their reaction to your reaction when you saw the finished building? They both burst into tears. It was like this enormous outpouring, this dam breaking. It’s hard for people when they’re on television, isn’t it? Cameras are pointing at you, and we all put up a front.

Is there a design trend you’ve really disliked? I’ve never been a fan of bling. There was a time when it suddenly became hugely mainstream. We saw it in all of our projects. People would build these beautiful homes and then spoil it all by hanging mirror balls everywhere. It was all a bit too much, and it still is.

What’s the one design mistake you most commonly see? My heart always sinks when I hear: “We’ve sacked the architect – my wife’s going to design it and I’m going to be the project manager. I’ve run a successful IT department. I know what I’m doing.” Really, the best buildings – the least compromised ones – are those that result from collaboration between great designers, great builders and great clients. The more you rely on people who are really good at what they do, the more you empower yourself.

Grand Designs Australia, with a special appearance from Kevin McCloud, starts October 10 on ABC TV.