He was speaking at a meeting of Alnwick Town Council’s business forum at which he forecast that retail will decline at the expense of online shopping.
However, he had a largely positive outlook about the future for Alnwick town centre providing that it adapts.
After a brief walkabout he said: “My initial thoughts are that it’s a very attractive place to visit as a tourist with its unique heritage and connections with the Percy family and the castle.
“It might also be a great place to live. I certainly can see why that would be the case for older people.
“However, I also understand why younger people might want to leave because I don’t see any evidence of youth culture and that is going to be a problem for the future.”
He has urged key stakeholders to look at alternatives to retail like entertainment, housing and leisure, education and arts spaces.
He highlighted the former Corn Exchange as having great potential.
“It ought to be a fresh food emporium with restaurants and a micro-brewery to boost the night-time economy,” he suggested. “It could be a hub for festivals and music events. I think it would be a fabulous space for that kind of thing.”
He also suggested that empty or uncared-for units should be bought, by compulsory purchase if necessary.
“They could be turned into incubator units for technological businesses, retail business and young people to experiment,” he said. They could become a cultural hub.”
He suggested that Bondgate Within should be included in any pedestrianisation plan.
“You need to get rid of cars from there and make it more welcoming for people, with more restaurants with tables outside in the summer to make it a focal point.”
He welcomed plans to free up more space for parking on the edge of town which could be used by workers, freeing up town centre short-stay spaces for visitors.
“There are some wonderful frontages here in Alnwick but the signage around the town isn’t great,” he added.
He suggested a re-branding exercise was needed and felt the Duke and Duchess of Northumberland should have a role to play.
“They are intrinsically linked with Alnwick and should be investing in it,” he said.
“There are things I don’t like, such as the number of charity shops and there are a lot of banks which I think will disappear from the high street but, all in all, I think Alnwick has a lot going for it.”
Coun Gordon Castle, who accompanied him on his walkabout, said he remained optimistic about the future.
He said: “We must have one of the most attractive streetscapes in the country and look at the attractions nearby like the castle, garden and Barter Books.
“The struggle we have is our small population and distance from the likes of Newcastle but I maintain that Alnwick has enormous potential, even though the retail offer could be improved.
“Some people might say that Alnwick is dying but they are wrong. It’s changing and must adapt further.”
A hugely successful retail businessman, Mr Grimsey has made radical suggestions for the regeneration of Britain’s high streets and town centres by encouraging them to move away from traditional retail, re-fashioning them as public spaces focused on their respective communities and including alternatives to retail like entertainment, health, housing and leisure, education and arts spaces, in order to make high streets relevant and viable once again.
Many of his ideas are now being effectively encouraged by the government through its new Future High Streets Fund.
During his career, Mr Grimsey earned a reputation as a turnaround specialist, masterminding the recovery of DIY group Wickes and also Iceland foods and Focus DIY.
Over the last six years he has published three respected works on the problems and futures of high streets, Sold Out, in 2012; The Grimsey Review, in 2015; and The Grimsey Review 2: The Vanishing High Street, last year.