Pizza Hut is trying out different designs in four of the new-build restaurants it is opening this summer, in what it says is part of a £1.5m investment in interiors concepts designed to avoid the "cookie cutter" syndrome and see off competition from rival chains.

Paul Young, a director of S&P Architects, which is designing sites for Pizza Hut in Eastbourne and Truro, both due to open in August, said a "huge sea-change" was taking place in the fast-food industry, and interiors revamps are playing a big part. The industry is recognising a need to move upmarket, he says, shifting from identical themed venues to more sophisticated one.

People wanting a pizza "are usually after a PizzaExpress experience," Young said, and consequently Pizza Hut is addressing its 'red box' interiors and seating arrangements. He said: "We're introducing crisper, cleaner, more transparent designs, the restaurant equivalent of an Audi showroom." "Friendlier" booth seating is replacing disconnected tables and "cartoon pizza" graphics will be phased out.

Another design company, Scurr & Partners, has designed a new look for a venue in Preston due to open next month, as well as interiors for a new Pizza Hut in Leeds.

Pizza Hut's head of design and construction, John Graham, said each of the four restaurants will incorporate different design elements across lighting, furniture, external signage, graphic images and floorings.

He said each consultancy was experimenting with one or two stores" "We don't want to standardise our restaurants; we want to reinvent the interiors without alienating customers."

Pizza Hut UK has become "more radical and adventurous" with its design after successes with restaurant interiors trials, and moved away from the "cookie-cutter mentality" of the parent company's restaurants in the United States, Graham said.

Pizza Hut. which is owned by Whitbread in the UK, currently has more than 500 British outlets, including 350 dine-in restaurants. It plans to open 35 new-build stores this year.