We live in an era where technologies are advancing at an unprecedented rate. In the last decade in particular, there is always something new emerging in our building industry every year – artificial intelligence (AI), Internet of Things (IoT), robotics, drones, video analytics, nano-materials, 3D printing, Modular Integrated Construction (MiC) and Multi-trade integrated Mechanical, Electrical and Plumbing (MiMEP). These new technologies are beginning to change the construction and property sectors.

Access to contemporary technologies would make a tremendous difference, given the variety of breakthrough technologies now available. With them, the performance of building functions like energy utilisation, refuse handling, fire protection and vertical transportation should become more advanced and efficient, giving rise to a paradigm shift in the way we configure our buildings.

This article will describe ten promising technologies that have the potential to advance our building designs through 2025 and beyond. These technologies are classified into three areas of applications as indicated in the following headings.

Energy and environment

(i) Radiative cooling

Radiative cooling (Figure 1) is a passive cooling method. It can achieve a continuous cooling effect by dissipating heat, as thermal radiation, into the cold universe through the transparent channel of the atmospheric window (8–13 μm). This cooling mechanism is now commercially available in the form of electricity-free cooling paint applied to building envelopes, Photovoltaic (PV) panel frames, and exposed surfaces of air-conditioning plant. Its latest version takes the form of a quasi-transparent film that can be applied to windows without negative effects on their visibility. In the future, when these technologies are broadly applied, every building may well become a “passive house” where cooling can be generated without the use of electricity.

Figure 1: Radiative cooling paint

(ii) Photovoltaic (PV) glass

PV glass (Figure 2) is another emerging technology that is being continuously improved. The areas of improvement are their energy conversion efficiency as well as the degree of transparency—a high degree of transparency ensures that occupants are not prevented from enjoying external views. This technology may potentially be applied to curtain walls, skylights, canopies, spandrels and ventilated facades. Besides buildings, PV glass can be applied to canopies for car parks as well as canopies for sports and recreational facilities. In fact, the HKSAR Government is now putting efforts to explore the wider use of building-integrated PV (BIPV) system. The broad use of this technology in new buildings and retrofit applications in the future will certainly accelerate Hong Kong’s journey towards carbon neutrality.

Figure 2: Photovoltaic glass

(iii) Walk-on PV panels

Walk-on PV panels (Figure 3) form an electricity-generating solution that can convert an ordinary outdoor space into a micro-power-generating station. They can be applied to pavements, garden spaces, roofs and podium surfaces. In terms of retrofit applications, building roofs designated as fire refuge spaces can continue to function as such even after the retrofit of walk-on PV panels. Their broad application can help the city realise the vision of “Every building or public space a power house”.

Figure 3: Walk-on PV panels

(iv) Balcony solar hot water system

Balcony solar hot water system (Figure 4) is a technology being applied to some projects in Mainland China. It may potentially be applied to projects in Hong Kong given how common balconies are in local new residential buildings. More often than not, the solar heat radiating from the sun down the balconies is not utilised at all, leading only to occupant discomfort. In contrast, with a device that collects the energy and converts it into hot water, the occupants coming home at night would be able to enjoy a hot water bath. The solar heater can be backed up by an electric air-to-water heat pump at those times when sufficient sunshine is not available. In any case, the amount of energy consumed for hot water production would be reduced. The city’s greenhouse gas emissions can thereby be reduced.

Figure 4: Balcony solar hot water system

(v) Intelligent weather-controlled windows

Intelligent weather-controlled windows (Figure 5) are a simple yet effective solution that is much needed in any kinds of intelligent buildings, especially in their common corridors and lift lobbies. In the spring season of a city with a humid climate, condensation often occurs in the common areas. Each of these windows is fitted with a chain actuator that can open or close it automatically according to command from a central weather station. During typhoon or a fire, the window can be programmed to close or open accordingly. The security staff can save a considerable amount of work. Huge benefits can accrue to high-rise buildings with a tremendous number of windows.

Figure 5: Weather-controlled window

(vi) Intelligent material-recycling station

Intelligent material-recycling station (Figure 6) is another promising technology that facilitates building operations. One application area is refuse chutes. In the past, refuse chutes could only be placed in locked refuse rooms for fear that oversized articles or those items undesirable in some other ways might be deposited into the chute and clog it up. However, with the advancement of machine vision, the entrance port of a refuse chute can be fitted with AI equipment to determine whether the entering material is papers, plastic bottles or metal cans. The AI equipment can then make a judgement on the material’s acceptability for recycling. This advanced feature of refuse chute made it possible for residents to operate it, a role otherwise restricted to trained workers. With such refuse chutes, a future can be expected in which every floor of a high-rise building, rather than just the ground floor, will have a material recycling station.

Figure 6: Intelligent material-recycling station

Fire Safety

(vii) Internet of Things (IoT) sensors for fire and smoke doors

IoT sensors for fire and smoke doors (Figure 7) are an innovative solution to the prevalent problem of these doors jamming at the open position at the fire escape staircases of residential buildings. In the past, this problem, often undetectable, could lead to severe tragedies when there is a fire. Owing to IoT technology, every single fire door can now be monitored 24 hours a day, seven days a week; The security personnel would be alerted if any door is jammed at the open position.

Figure 7: Fire door sensor

(viii) Strengthened fire-detection and fire-fighting provisions inside flats

Strengthened fire-detection and fire-fighting provisions inside flats (Figure 8) are a natural development from the increased popularity of open kitchens. The old fire code of Hong Kong mandates that a kitchen be equipped with an auto-closing fire door. Such a design is not user-friendly for occupants and the sweep path of the fire door is often incompatible with the small-flat design, in which every square inch counts. As a result, occupants often dismantle the kitchen doors in order to save space. Because of the expected prevalence of open-kitchen design in the future, as well as the lessons learnt in the past about severe local residential fires, it is reasonable to expect more intelligent fire detection and automatic fire extinguishing devices (such as sprinkler protection for living spaces) to be incorporated shortly into our homes, which are becoming more and more intelligent. In particular, since construction methods like MiC and MiMEP are gaining traction, the way should be cleared for sprinkler pipes’ integration into residential structures. When in place, these kinds of fire equipment would greatly reduce the likelihood of residential fire tragedies occurring in our high-rise, high-density living community.

Figure 8: Strengthened fire provisions in a MiC-built home

Vertical transportation

(ix) Automated goods delivery

Automated goods delivery (Figure 9) is a promising solution to a problem brought about by the pervasiveness of online shopping. Traditionally, goods purchased online are delivered to the destinations by workers manually, but the intended recipients may potentially be absent from home. In cases of postal delivery, the recipients have to collect their mails at the ground-floor mailboxes. Both situations are inconvenient. With the advancement of robots and drones, the future will conceivably find every home equipped with a recipient port (with a check valve) facing the common corridor for the receipt of robot-delivered goods or mails; and, additionally or alternatively, a recipient port at the balcony for the receipt of drone-delivered goods or mails.

Figure 9: Drone-based delivery system

(x) Advance elevator-calling

Summoning elevators in advance via phone-enabled presence detection is a solution for busy citizens wishing to save time in vertical transportation in a high-rise building. There are plenty of buildings that are over 40 storeys high, and, with these, the transit time of elevator is considerable. In the past, elevators could only be called at the lift lobby. Nowadays, zone presence detection, which can be set up via a mobile application, may inform a building automation system if someone has entered the building or left his flat, thus initiating an elevator call in advance. As he walks towards the lift lobby, the elevator is already on its way to take the call.

Conclusion

This article describes ten innovative technologies that have the potential to revolutionise our residential dwellings. The author hopes that engineers in various disciplines can collaborate to effectuate these technologies’ real applications in new buildings or existing building renovations. As inventors and users of new technologies, engineers have an indispensable role to play in transforming Hong Kong into a more modern and liveable city. Let us work together to make our dream of smart, green and safe homes come true.

About the author: Ir Dr Eddy W T Lau is a Fellow of the HKIE in the Energy and Building Services Disciplines. He has an interest in smart green buildings and is the Head of Green Labelling at the Hong Kong Green Building Council.