By 2020 restaurant architecture and design will embody both high-tech advancements and low-tech hospitality, appealing to consumers hungry for modern flourishes like cashless payments as well as the old-fashioned human touch.

The lines between industry segments will blur further, with quick-service chains adopting the upscale decor of casual-dining competitors — localized through art and graphics — and full-service and fast-casual brands adopting tools to speed up service.

At the same time, operators’ efforts to reduce the costs of build-outs, cut waste and bolster their green credentials will have some repurposing old buildings and many investing in energy-efficient equipment and materials.

Quick-service restaurants will offer upgraded seating and fixtures that are more posh than today’s plastic and institutional looks. Newer units from Wendy’s and Burger King are headed in this direction already. “Who would have predicted 10 years ago that you’d see upholstery at McDonald’s?” asked Dennis Lombardi of WD Partners.

Advances in equipment and higher-quality prepared foods from boutique manufacturers will allow restaurants to reduce kitchen build-outs. The kitchen may be able to get by with a high-speed oven and water baths, which require no expensive hoods and ventilation, said Richard A. Keys of Food and Drink Resources.

The line between the front and back of the house could disappear altogether at some venues as customers clamor to learn more about how their food is prepared. Some full-service restaurants will put seating in — or in full view of — the kitchen, and many concepts will add more tableside exhibition cooking.

The emphasis on consistency in appearance among a chain’s units will fade, and restaurants from California to Connecticut will increasingly reflect their locales. Walls will have more local art and photography, and regional architectural vernacular will assert itself, with more operators repurposing existing spaces, such as old warehouses or fire stations. In addition to housing brand DNA in a unique space, the reuse of old buildings will give brands a “green” halo.

Customers already have a growing number of electrical devices, from smartphones to tablet computers, that demand charging, and by 2020 restaurants will provide a larger number of outlets and even USB ports as an amenity. Expect to see outlets conveniently at tabletop height and, in casual dining, at the bar tops.

While use of technology is projected to grow, more restaurants will offer special seating areas or zones away from the big screens and tablet computers for guests who want to unplug and concentrate on a social gathering with family or friends. In the near future, the option for seats away from technology might become the luxury that a table near the power outlet and Wi-Fi are today.

As cleanliness and food safety draw more consumer attention, microchip technology embedded in menus, napkin dispensers and condiment service areas will alert staff when they are near empty or need to be cleaned.

Not only will restaurant brands offer more energy-efficient unit models, relying on LED lighting, reduced-consumption equipment, and savvy heating and air conditioning systems, they also will recycle or compost all waste. And they will communicate that environmental story to their customers.

Restaurant formats will adopt the daypart flexibility already built into many menus. Rather than creating one design that is all things to all people, operators will specialize their venues to be quick, no-frills spots in the city and full-service gathering places in the suburbs. Within each restaurant, the seating, technology and even the walls will be moveable so that interior designs can be changed to better accommodate the daypart.

Restaurant unit sizes will continue to shrink, with square footage being shaved as equipment becomes smaller and more efficient, and back-of-the-house space morphs into something akin to a finishing kitchen. Experts suggest typical stores can trim 10 percent out of needed space without sacrificing seating.

With advances in voice recognition, drive-thru lanes will be staffed by Siri-like software — not crew members — that will be able to take orders in several languages. Within 20 years, experts expect the software to be sophisticated enough to recognize regional dialects.

Casual-dining brands will offer faster, smaller express versions of their brands to compete with the growth of fast casual. Red Robin already has created its limited-service Burger Works, Denny’s has its Fresh Express, and Red Lobster and Applebee’s offer versions in existing stores at lunchtime.

Digital ordering and payments will be standard. “The smartphone will be the wallet of 2020,” said Dennis Lombardi of WD Partners. “And cash will go the way of the AM band of the radio.”

Sources: Christian Davies of Fitch in Columbus, Ohio; Richard A. Keys of Food and Drink Resources in Denver; Dennis Lombardi of WD Partners in Dublin, Ohio