Hunched on the sleek rooftop beneath a darkening sky, the tripod-style robots look undeniably menacing as they loom over diminutive human figures.

This is not some post-apocalyptic nightmare image, however. On the contrary, says Andrew Watts, founder and CEO of British building engineering firm Newtecnic – it is a vision of people, machines and buildings working together in perfect harmony. 

The concept shows how the King Abdullah Metro Hub in Riyadh, Saudi Arabia could look in 30 years’ time. Newtecnic is working on the station ahead of the planned completion of construction later this year. And the picture released by the company exemplifies Watts’ vision of a new type of mechanical building. 

The changes to construction, engineering and maintenance will be fundamental by 2050, says Watts: “The use of drones for cleaning or maintenance is the tip of the iceberg. What they will be maintaining is itself about to be transformed, and the major transformations are based on 3D printing and rapid prototyping.”

The hugely customisable new technologies – combined with increased manufacturing costs in traditionally cheap countries such as China – herald a new type of construction, says Watts. In the coming years, he claims, construction companies will design, test and build bespoke parts for mechanical systems such as lifts or escalators on-site rather than paying and waiting for international deliveries. 

Advances in 3D printing are already making this a possibility – last year, GE Additive unveiled a prototype printer capable of producing metal parts with diameters of up to 1m. This new style of flexible and hyper-controlled manufacturing will change buildings themselves, says Watts. Whereas mechanical systems in buildings might today have standard lifespans of only 20 years, structures designed with machine interactivity in mind could last far longer. 

“Drones will be able to interact with them as if they are part of the building itself… machine and building being interdependent,” says Watts. 

Designed alongside each other, structures and drones could have complementary features; droids might combine legs and wheels for better manoeuvrability, and facades could sport climbing rungs for easy perching. While operators of large buildings might be unwilling or unable to hire human workers to replace defunct parts such as seals or panels, specially designed, machine-learning drones could do the job cheaply and efficiently. 

The economic advantages of interactive mechanical buildings and continued proliferation of accessible 3D printers and related technology lead Watts to think that his vision will be “absolutely global”. Indeed, others in the industry think the future may hold even more radical building technology. 

“I would push that boundary even further,” says Blane Judd, chairman of the Institution of Engineering and Technology’s built environment sector. With high demand for engineers, an ageing global population and a need to be more sustainable with available land and buildings, the industry may have to take another, smaller step – much smaller. Surpassing today’s predictive maintenance, intelligent nanotechnology could eventually detect faults and automatically correct them.  

“If you move on from drones and think about nanotechnology, and nanotechnology being sufficiently intelligent… it identifies the fact that it is defective and self-rectifies,” says Judd. “That could be to the point of self-replicating a component – almost the way the human body uses appropriate cells.”

So, even if the robots are taking over, maybe they still have something to learn from us.