Building facades play multiple roles – they protect against the weather, play a part in sunlight harvesting and even provide an aesthetic appeal to its viewers. However, recent incidents including collapsing building walls and concrete beams raise concerns about building safety. Is it time to reconsider the design of intricate artistic façades? This article explores the balance between safety and aesthetics.
Facades, serving as the outer skin of a building, reflect the artistic essence of the structure. The design of facades has become a significant battleground for architects, each vying for the most innovative and artistic expressions. In contrast to the conventional rectangular and square shapes, architects now explore designs with impressive shapes such as ovals, S or Z shapes, incorporating fins, vegetation, and other peripherals to captivate property developers, homebuyers, and passersby. Undoubtedly, these elements contribute substantially to the market value of new property projects.
Ironically, the author was recently invited to examine the issue of falling fins and cracked cement screed that pose a threat to the residents of some of these impressive developments. Clayford T. Grimm, a late ASTM member and masonry expert in America, addressed this concern in the March 2000 issue of The Construction Specifier, stating, “Masonry falls off a building facade somewhere in the United States about every three weeks. Over the past few years, at least 49 such masonry failures have resulted in 30 fatalities and 81 injuries.”
Incidents like these are not uncommon in Asia either. In Singapore, a decorative structure on a Housing Board block at 270 Pasir Ris Street fell from a height of at least eight stories on June 18, 2018. Fortunately, no injuries or fatalities were reported.
Meanwhile, in Malaysia, facade failures have also raised concerns in Kuala Lumpur. During a freak storm with strong winds on May 20, 2023, a wooden wall was “sucked out” from a 30-year-old flat on Jalan Loke Yew. Besides that, the collapse of a concrete beam in Kuchai Entrepreneur Park on August 15, 2023, resulted in damage to 10 cars, fortunately without any reported injuries or fatalities. However, this incident has once again heightened public concerns about building safety, emphasizing the inherent risks associated with complex and artistic facades.
It may be time to reconsider the design of such intricate facades, questioning whether safety should take precedence over aesthetic value during the design phase. Contrary to the notion that “simplicity is beautiful,” complex facades with numerous components are linked to a higher risk of errors. What if the falling pieces of fins pose a threat to residents, causing injuries or even fatalities? What precautionary measures are in place during the design and maintenance phases to ensure the safety of facades? Additionally, how do these measures address consistent issues such as leakage from the facades? And what factors contribute to the degradation and subsequent risks associated with facades? These are crucial questions that demand attention in balancing aesthetics and safety in building design.
Check out this video on best practices when it comes to designing and maintaining building facades.
Laws related to building facade design and maintenance
The legality surrounding facade design and maintenance is outlined in the Street, Drainage and Building Act, 1974 particularly in Section 85:
- Section 85(1b): The owner or occupier of any building accessible to the public must ensure the building is free from any condition that may endanger the lives or health of employees, the public, and other users.
- Section 85(2): If the local authority determines that the owner or occupier has failed to comply, they can issue a written notice requiring corrective actions within a specified period.
This extract from the Street, Drainage and Building Act 1974 emphasizes the responsibility of building owners to maintain their properties and ensure the safety of occupants. Furthermore, Section 21(a) of the Strata Management Act 2013 imposes a statutory duty on Joint Management Bodies to properly maintain and manage buildings, keeping them in a state of good and serviceable repair. While there might not be specific mandatory requirements for facade inspection by local authorities, building managers have an inherent duty to exercise due diligence on behalf of owners to ensure the safety of building facades is not neglected.
In the event of premature failure, such as leakage within the typical service lifespan of facades, building owners or managers can explore recourse through a Latent Defect based on Section 6A of the Limitation (Amendments) Act 2018. This is particularly relevant if the defect is discovered after the expiry of the Defect Liability Period under the Housing Development (Control and Licensing) Act 1966. To build a case in such situations, a thorough investigation report by a certified facade inspector, professional engineer, or architect is necessary.
Which facade components are vulnerable to degradation?
The degradation of components on facades is a multifaceted issue influenced by various factors. The major components susceptible to deterioration include:
- Masonry external walls: These walls often integrate concealed concrete columns, beams, slabs, structural brick walls, shear walls, and masonry infill.
- Exterior Cladding System: The system used to clad the exterior of the building.
- Windows: Including their frames and seals.
- Curtain Walls: External walls that do not carry the load but are designed to keep out the weather.
- Frameless Glass Walls: A modern design feature that requires careful consideration.
- Balconies and other peripherals: Additional features that contribute to the overall aesthetic and functionality.
These components are exposed to weathering, vibrations, and movements caused by wind loading and soil movement. The escalating impact of climate change, characterized by stronger winds and increased precipitation, raises the risk of rainwater ingress. Hotter heat waves intensify heat-induced stress on building materials, causing expansion and contraction. Seismic activities, vehicular traffic, and nearby construction can also lead to cracks in building facades.
In tropical regions, many concrete structures with brick infill are cement-rendered. The use of materials like clay bricks, cement bricks, aerial blocks, and concrete shear walls introduces variations in thermal behaviour due to different coefficients of thermal expansion among these materials. Understanding and addressing these diverse factors is crucial for effective facade design, maintenance, and durability in the face of evolving environmental challenges.
Differential thermal expansion among various components has led to cracking on external walls, especially noticeable on the walls on the highest floor with an adjoining flat roof. Controlling heat is crucial to mitigate cracking on facades in such locations. Effective heat insulation methods include the use of single-ply membranes, coatings, vegetation, or implementing shedding with a raised floor system or roofs.
It’s worth noting that cracking tends to be more severe on external walls with dark paint due to low reflectance and the subsequent heat absorption. The use of dark paint is not recommended in specifications during the design or refurbishment stages, considering the concerns related to cracking and maintaining thermal comfort in indoor spaces. This advice aligns with guidelines outlined in “Defects in Masonry Walls, Guidance on Cracking: Identification, Prevention, and Repair,” as published by the International Council for Research and Innovation in Building and Construction. Adhering to these guidelines can contribute to the longevity and resilience of external walls, minimizing the risk of cracking and ensuring indoor thermal comfort.
Effect of climate change on building facades
The frequency of unprecedented strong winds has increased, especially in urban areas, where rapid urbanization and dense building structures contribute to the phenomenon. The close proximity of buildings forces the wind to travel faster over longer distances. This effect is amplified by factors such as the heat island effect, where urban areas experience higher temperatures than their rural surroundings, and climate change, which increases the moisture load and hot air content, further energizing the wind.
These combined factors create an environment where strong winds are more prevalent and can pose challenges to building structures and infrastructure. Architects, urban planners, and engineers must consider these changing weather patterns and environmental conditions in their designs and construction practices to ensure the resilience of buildings and the safety of occupants.
The phenomenon of air suction, particularly on the leeward side exposed to turbulent wind, becomes more pronounced with increasing wind speeds. This effect was evident during Hurricane Ike in 2008, causing significant cladding damage to high-rise structures in downtown Houston. Find out whether our buildings in Malaysia can withstand climate change and natural disasters?
Issues with ageing buildings
Aged buildings commonly experience issues such as carbonation and leakage, often accompanied by efflorescence. The corrosion process can be accelerated, especially in the presence of chloride ions, acting as catalysts in oxidation/corrosion. In Malaysia, where ambient humidity levels are high, inadequate concrete cover—less than 25mm for RC slabs, 40mm for columns, and liquid retaining structures—increases the risk of corrosion.
To address these concerns, compliance with BS EN1504 is recommended, particularly in the diagnosis and repair of concrete structures. This standard provides guidelines for protective systems and rehabilitation measures, ensuring the durability and structural integrity of buildings, especially in regions prone to adverse weather conditions.
Importance of Building Facade inspection
The mandatory inspection of facades has become a crucial regulatory measure in some developed countries, particularly in response to the challenges posed by ageing cities with dense concentrations of skyscrapers. The close proximity of people walking and living in these densely populated buildings has raised concerns about the potential risks of falling objects, leading to occasional injuries and fatalities.
In the United States, the Façade Ordinance was enacted and adopted in 1980, starting in New York City. Presently, over 15,000 buildings across various cities in the United States are subject to local municipal laws mandating periodic inspections of building facades. These local regulations, commonly referred to as facade ordinances, aim to ensure the safety and integrity of building exteriors.
Hong Kong implemented a mandatory facade inspection through the Building Inspection Scheme in 2012. Owners of buildings aged 10 years or more (excluding those lower than three storeys) are served with statutory notices, requiring them to appoint a qualified person for inspections and to supervise necessary repair work. Subsequent inspections are then mandated every five years. These measures reflect a proactive approach to building safety and public well-being, responding to the potential hazards associated with ageing structures in densely populated urban environments.
The mandatory facade inspection trend has extended to Singapore, where rules have been in place since March 2018. These regulations apply to buildings above 20 years old and taller than 13 meters, approximately the height of three stories. Certified facade inspectors, trained by the Building and Construction Authority of Singapore, conduct inspections every seven years. The use of drones, especially those equipped with infrared thermographic imagers, is recommended for thorough inspections.
Concerns regarding falling objects are also prevalent in Malaysia, even if not widely reported. The adoption of new materials and technology in facades, such as non-absorbing glasses and cladding, has raised concerns about water leakage. These materials, while elegant, have limited tolerance to leakage, which can be exacerbated by severe environmental pollution, particularly in industrial or high-traffic areas. The worsening effects of greenhouse gases, heat islands, and urbanization further accelerate the degradation of sealants that secure these glasses and claddings.
How to conduct building facade inspection?
In Malaysia, the awareness of facade safety and maintenance has gained attention due to the rapid construction of high-rise buildings in urban areas and the prevalent issue of water leakages. In North America, facade inspections are typically carried out by practising architects or engineers, while in Hong Kong and Singapore, certified facade inspectors follow prescribed protocols.
The facade inspection process involves reviewing the service history, conducting a visual survey under proper lighting conditions, performing close-up inspections of select portions, and analyzing findings. Close-up inspections with physical contact and additional testing, such as pull-out tests or endoscopic inspections in cavities, prove effective in detecting loose and falling objects.
Critical items inspected include, but are not limited to:
- Loose or missing tiles on the facade
- Cracks
- Bulging, bowing, separation, and delamination
- Corrosion of metallic parts embedded in external finishes
- Spalling
- Cracked glass
- Worn sealant
- Dampness
This comprehensive inspection approach aims to ensure the safety and integrity of building facades in the face of evolving urban environments and construction practices.
Prevention is better than cure. This is particularly relevant to façades whereby any falling objects may cause injury and mortality to the occupants and by-passers. Thus, façade inspection is essential in such prevention. Although façade inspection is not mandatory in Malaysia for the time being, precautionary measures and proactive action must be taken by the building managers and owners to inspect and repair the façades for the safety of the buildings and the occupants.
Property owners should also find out why building condition surveys are extremely important.