In 2018, the UN released an article stating that 55% of the world’s population already lived in urban areas, predicting that by 2050 this percentage would reach 68%. This trend toward greater urbanization carries with it several implications regarding environmental degradation and social inequality. According to National Geographic, urban growth increases air pollution, endangers animal populations, promotes the loss of urban tree cover, and heightens the likelihood of environmental catastrophes such as flash flooding. These health hazards and catastrophic phenomena may be more likely to impact poorer populations, as larger cities tend to demonstrate higher rates of economic inequality and uncontrolled growth tends to produce unequal distributions of space, services, and opportunities.
To mitigate these negative effects of urbanization, designers are increasingly prioritizing sustainability and the maximization of available space – allowing more people to occupy less space with a smaller footprint.
With an increasing interest in sustainability, the interiors of the future are likely to utilize new technologies and smarter methods to minimize energy use and decrease emissions. One of the most significant ways this transformation will occur is through the use of less energy-intensive materials, shifting from high-energy materials such as cement, glass, brick, and steel toward alternatives including stone, rammed earth, hollow concrete, and wood.
With the cement industry, for example, being listed by the EIA in 2013 as the most energy-intensive manufacturing industry, a lower reliance on this material in cities around the world would constitute an important step in the direction of more sustainable urban living. Domestic and professional interiors of the future might therefore involve more earthy or wooden interiors as opposed to the cold and detached greys of modern steel, concrete, and glass spaces.
An important consideration within this shift is necessarily the issue of location, as the transportation of heavy materials can be a high contributor to embodied energy and overall costs. Eschewing the universal claims of many modern architecture movements, we can foresee that future interiors will develop from localities, conforming to particular climates and landscapes to lower energy use and emissions passively. Not only will this transformation occur by utilizing local materials and eliminating transportation costs, but consideration of local climates would allow architects to utilize passive solar design and passive cooling to decrease the need for heating and air conditioning.
These preventative measures will be aided by a plethora of new technologies designed to optimize energy use and decrease construction waste. In designing new spaces, architects, engineers, and construction workers are likely to use Building Information Modeling (BIM), a collaborative technology that facilitates hyper-detailed planning and execution to decrease waste, lower costs, improve sustainability, and promote creativity. In tandem with BIM, designers may use energy modeling software to produce buildings that maximize energy efficiency.
Thanks to the bird’s eye perspective project leaders gain using BIM, they can do everything better, faster, and at a lower cost — using fewer resources. [...] The ability to complete the projects efficiently and smoothly, sometimes ahead of time, allows the architectural visionaries to explore creative options to go the extra mile. Hence, the smooth collaboration, quick feedback, and holistic oversight help the design masterminds to soar to take their projects to new creative heights. 
What with the high cost and environmental impact of new constructions, however, future interiors will likely not only consist of new buildings but include retrofitted existing structures as well. This industry has been growing rapidly, with over $500 million being spent on retrofitting old hotels in 2018 alone. Much of this transformation occurs through the integration of smart building technology.
By 2050, the internet of things will have become fully integrated into domestic spaces, employed not only to improve user efficiency but to limit energy use, stop food waste, and track water use. Home automation systems will turn off lights, suspend heating and air conditioning, and stop running faucets and stoves left on. This type of automated technology may encompass new security systems as well – it’s possible that in the next 50 years, keys and key cards will have been supplanted by mobile access technologies. In other words, the interiors of the future will be immersed in new technologies.
Buildings that long measured temperature now also measure humidity and CO2, continuously and precisely designing rooms for maximum occupant comfort and environmental impact. Stored biometric data prevents security breaches and increases the speed with which people can flow through buildings. 
Interest in nature and technology may manifest aesthetically as well, with the minimalistic approach to materials, costs, and energy use finding its way into minimalist aesthetics and biophilic design. Probably, interiors will increasingly be rendered in white and beige, and furniture in clean shapes and simple forms. Vertical gardens, green roofs, and living plants are also finding their way into contemporary interiors, the aesthetic commitment to nature mirroring an increased dedication to sustainability.
As urban living spaces decrease in size, urban design grows more and more innovative in its employment of multi-functional spaces. Single spaces may accommodate a kitchen, living room, and bedroom all at once through efficient built-in storage spaces and open plans with thoughtful lighting. One inventive way in which designers are achieving this integration is through retracting walls, allowing spaces to transform completely. A company called Skyfold, for example, has developed vertically foldable walls with customizable graphics and sound-proofed acoustics, adaptable to a wide range of interior spaces for a plethora of purposes. Other designers may use transformable furniture, multi-purpose shelving, or retractable storage, as covered in our space-saving kitchen article. These integrate smoothly with smart building technology, as retractions and transformations may be initiated by mobile apps or automation.
Thus, building interiors are expected to change dramatically, but along three main axes of consideration: sustainability, technology, and efficiency. These three impulses of transformation will occur in tandem, rather than separately, with each influencing and facilitating the other. Hopefully, as a result, cities will be more sustainable, flexible, and inclusive – though there is still a long way to go before then.
Read more about these topics on the dormakaba's blog.
 Dr. Kai Oberste-Ufer, et al. "A Peek Inside BIM’s World Domination – Dormakaba Blog." EN - Dormakaba Blog, 21 Jan. 2020, blog.dormakaba.com/a-peek-inside-bims-world-domination/.
 dormakaba Editorial Team, et al. "How to Teach Your Old Building to Become Smart – Dormakaba Blog." EN - Dormakaba Blog, 2 Dec. 2019, blog.dormakaba.com/how-to-teach-your-old-building-to-become-a-smart-building/.