Uber has made an early stage approach to buy food delivery firm Deliveroo, Bloomberg reports, in a move that would see it increase its disruption of the real estate business.

Deliveroo would hold out for a valuation of at least $4B, according to the Financial Times. It was valued at $2B last year. The London-based company pioneered the service provided by UberEats, delivering restaurant food to customers in 200 cities across Europe. UberEats delivers to 300 cities worldwide, but is smaller than Deliveroo in Europe.

UberEats and Deliveroo have been disrupting the brick-and-mortar restaurant business through their use of technology since they were set up in 2013 and 2014, respectively. But a purchase of Deliveroo would give Uber a toehold in the real estate business in a different way.

Deliveroo has pioneered the use of dark kitchens, centralised kitchen facilities set up by the company so restaurants can fulfil orders from the app outside of their restaurants.

These dark kitchens tend to be repurposed buildings or more often shipping containers fitted out with the kitchen equipment required to cook an off-site meal exactly as it would be cooked in a restaurant kitchen. Diners can get restaurant quality food without the need for a physical restaurant space.

Deliveroo has more than a dozen dark kitchen sites across the U.K., which it previously called Rooboxes but has now given the more prosaic name Editions.

Dark kitchens have traditional restaurateurs examining their business models.

“Dark kitchens are something totally new for us, and we are having to adapt. We are competing against a different animal now,” Vapiano Advisor and Former Executive Board Member Mario Bauer told Bisnow’s London Retail Revolutions event in July.

“We might spend €2.5M to fit out a new restaurant,” he said. “If you are a new entrant now you can take space in a dark kitchen, pay a 30% commission and you have no upfront cost. We can compete, but we have to put in a lot more investment up front.”