The maker of the Roomba robotic vacuum, iRobot, has found itself embroiled in a privacy row after its chief executive suggested it may begin selling floor plans of customers’ homes, derived from the movement data of their autonomous servants.

“There’s an entire ecosystem of things and services that the smart home can deliver once you have a rich map of the home that the user has allowed to be shared,” said Colin Angle, iRobot’s boss.

That possibility has led to a shift in direction from the company technologically. While all of the housecleaning robots in its range are capable of navigating around a room, only the most advanced machines it makes do so by creating a mental map of the space; its dumber bots simply move almost randomly until they’re pretty sure they’ve covered the whole area.

Angle told Reuters that iRobot, which made Roomba compatible with Amazon’s Alexa voice assistant in March, could reach a deal to sell its maps to one or more of the Big Three – Amazon, Apple and Google’s Alphabet – in the next couple of years. None of the three commented on this story.

The plans have been received positively by investors, sending iRobot’s stock soaring to $102 in mid-June from $35 a year ago and giving it a market value of nearly $2.5bn on 2016 revenue of $660m.

All of iRobot’s Roombas use short-range infrared or laser sensors to detect and avoid obstacles, but in 2015 iRobot added a camera, new sensors and software to its flagship 900-series Roomba that gave it the ability to build a map while keeping track of their own location within it.

So-called simultaneous localisation and mapping (Slam) technology enables Roomba, and other higher-end ”robo-vacs” made by Dyson and other rivals, to do things like stop vacuuming, head back to its dock to recharge and then return to the same spot to finish the job.

The company’s smart home vision has helped bring around some former critics. Willem Mesdag, managing partner of hedge fund Red Mountain Capital – who led an unsuccessful proxy fight against Angle last year and wound up selling his iRobot shares – is now largely supportive of the company’s direction.

“I think they have a tremendous first-mover advantage,” said Mesdag, who thinks iRobot would be a great acquisition for one of the big three. “The competition is focused on making cleaning products, not a mapping robot.”

But consumer advocates have been more concerned by the proposal. Selling data about users’ homes raises clear privacy issues, said Ben Rose, an analyst who covers iRobot for Battle Road Research. Customers could find it “sort of a scary thing,” he said.

Jim Killock, executive director of the Open Rights Group, concurred, saying: “This is a particularly creepy example of how our privacy can be undermined by companies that want to profit from the information that smart devices can generate about our homes and lives.

“Smart household products may enable companies to obtain information that we consider to be private, such as floor plans of where we live. However, this is not necessarily personal data as protected under data protection law.

“Companies should treat data collected in people’s homes as if it is personal data and ensure that explicit consent is sought to gather and share this information. Taking an ethical approach, rather than complying with minimal legal requirements, would build trust with customers.”

Angle said iRobot would not sell data without its customers’ permission, but he expressed confidence most would give their consent in order to access the smart home functions.

The company’s terms of service appear to give the company the right to sell such data already, however. When signing up for the company’s Home app, which connects to its smart robots, customers have to agree to a privacy policy that states that it can share personal information with subsidiaries, third party vendors, and the government, as well as in connection with “any company transaction” such as a merger or external investment.

“Maybe that doesn’t unnerve you, but it probably should,” says Rhett Jones of technology site Gizmodo. “This is all part of the larger quest for a few major companies to hoover up every bit of data about you that they can. Now, they want to know all about your living space.

“Going through the iRobot terms of service, you can see just how much data is already being collected on a daily basis just by clicking like on a Facebook page or visiting a corporate website,” Jones adds. “And that data will likely be just as insecure tomorrow as it is today.”

At the opposite end of the market, iRobot faces competition from companies not caring at all about smart mapping technology, who are driving down the cost at the entry level. A rising group of mostly cheaper competitors – such as the well-reviewed £229 Eufy RoboVac 11 that’s more than £100 cheaper than the comparable Roomba 650 - which are threatening to turn a once-futuristic product into a commoditised home appliance.

An iRobot spokesperson said: “iRobot does not sell data customer data. Our customers always come first. We will never violate our customer’s trust by selling or misusing customer-related data, including data collected by our connected products. Right now, the data Roomba collects enables it to effectively clean the home and provides customers with information about cleaning performance. iRobot believes that in the future, this information could provide even more value for our customers by enabling the smart home and the devices within it to work better, but always with their explicit consent.”