With countless buildings on the verge of collapse across the country, CW speaks to industry experts to find what it takes to keep our structures stronger, and safer.One crack, a tremor, a loud sound…and collapse! Buildings fall. This is true to India, and the string of accidents reported in recent years is testament to this. Consider this: Last September, five people were killed after an apartment block collapsed in Delhi; months earlier, a six-storey building collapsed on the outskirts of Delhi, killing nine; in March, a four-storey, under-construction building collapsed at Dharwad in north Karnataka. These are just some recent mishaps – unfortunately, there have been more.In fact, millions of Indians live in dilapidated buildings at the risk of collapse during the rains. Recent reports have indicated some statistics from the busy cities: Mumbai has 4,299 dilapidated buildings, of which, 633 come under the C1 “extremely dilapidated” category; the Bruhat Bengaluru Mahanagara Palike has so far identified 52 structures that are in a dilapidated state and run the risk of collapsing; last year, Kolkata Municipal Corporation issued notices to 52 old and dilapidated buildings located in different areas under its jurisdiction. What’s more, the condition and quality of the Indian building stock is poor when it comes to seismic performance and fire-outbreaks. (See box on ‘Are buildings designed for seismic performance?’ and ‘Why are buildings not safe from fire outbreaks?’)  What leads to a collapse?The reasons are often related to planning, design and material. The use of inferior construction material is believed to be the root cause that reduces the life of a building.  Some common causes for collapse today, according to Dr Paresh Shah, Professor & Dean, Faculty of Technology, CEPT University, are “improper geotechnical investigation; poor quality RCC construction practices; and improper formwork practices, inadequate stripping time, lack of re-shoring or shoring to lower floors.” According to Dr Pramod Kumar Gupta, Professor, Structural Engineering, Department of Civil Engineering, IIT-Roorkee, “In planning, we have to check the load transfer mechanism. Here, the external load, which may be owing to gravity or earthquake, should be transmitted to the foundation without creating any structural damage to the structural elements. The foundation should be strong and stiff enough to transfer the load to the soil or earth. So, an appropriate structural form may address this issue.” Dr Gupta adds that before designing any structure, an analysis is carried out, where reactive forces and associated deformations in different structural elements are determined using appropriate techniques. Thereafter, the design of elements is carried out by choosing a suitable material. “Choice and quality of material are key parameters these days and proper quality control should be ascertained when it comes to material,” affirms Dr Gupta. In his view, if all these steps are followed with due care, it would be near on impossible for any structure to collapse before reaching its age. Building a strong foundationA building’s foundation performs a number of functions, such as bearing the load of the building, anchoring it against natural forces, and isolating it from ground moisture. Thus, a poorly constructed foundation can be hazardous for the occupants.“The primary function of a building’s foundation is to form the basis and hold the structure together,” avers Shabbir Kanchwala, Senior Vice President, K Raheja Corp. “A house anchored to its foundation will retain its structure better and be less likely to be swept away in a natural disaster.”And, Dr Niranjan Hiranandani, Founder & Managing Director, Hiranandani Group and President, NAREDCO, shares, “An accurate geotechnical investigation helps to build a strong foundation. Selecting the correct type of foundation – pile or open foundation – and ensuring the most appropriate founding strata are other important factors.” He believes the concrete foundation should be properly vibrated to ensure voids in the concrete have refrained.“Structural consultants and civil contractors have a significant role to play,” says Deepak Suvarna, Chief Projects Officer-Head Projects, Mahindra Lifespaces Developers. “Expertise in concrete technology is a prerequisite. Also, exhaustive soil investigation and effective designing of foundation systems as per soil conditions are essential. Water-prone areas are best avoided and a detailed subsoil drainage system helps to ensure foundation strength.” A strong foundation can withstand natural disasters or shocks and take adequate loads in most eventualities.“Designing a building foundation is done in a way that the weight of the entire structure is distributed evenly to prevent the subsoil from spreading,” says Samyak Jain, Director, Siddha Group. “It is crucial to assess the soil type; loam, rock, sand and gravel are good as foundation-friendly soil. To get a stronger base, concrete needs to be poured in deeper trenches dug in the soil till a hard surface is reached.”For his part, Rohit Poddar, Managing Director, Poddar Housing and Development, and Joint Secretary, NARDECO Maharashtra, lays down various steps: “First, you need thorough soil investigation; then half-meter contour. After this, you need to slightly overdesign the load-bearing capacity of the foundation; strengthen the foundation through a continuous pour process; give sufficient time and use a modern curing compound; and provide anti-termite treatment and waterproofing treatment according to international standards. Material advantageConcreting operations such as mixing, transporting, placing, compaction and curing are important to deliver optimal quality. The complete strength of a structure is directly proportional to the properties and quality of materials and the quality of construction.Samyak Jain refers to two types of concrete that construction companies use: Ready-mix concrete (RMC) and site-mixed concrete. “The quality of both types is dependent on the number of formulas and steps,” he says. While application of RMC is recommended for construction of high-rise structures, especially during lack of proper logistical support, the quality of concrete mixed on site can be enhanced with stricter supervision and correct inputs.That said, Prof Manu Santhanam, Department of Civil Engineering, IIT-Madras, avers, “RMC has an advantage in terms of the quality of the blend used, compared to site-mixed concrete.” Further, speaking from his experience over the years and data analysis, Dr Hiranandani believes mixed concrete on site that has been produced with a scientific and systematic way along with appropriate R&D helps establish a system in place that ensures better quality. “Further, the ‘garbage-in, garbage-out’ concept also applies to the production of concrete,” he contends. “Hence, it is important to set criteria for the right selection of material, testing parameters and acceptance criteria.” Why are buildings not protected from fire outbreaks?Among the most recent reports, 20 students were killed and several injured after a major fire broke out – triggered by a short circuit – at a coaching centre in Sarthana area of Surat.  According to India Risk Survey (IRS) 2018, as reported, fire outbreak is the third biggest risk to business continuity and operations. “The recommendations for construction of low-rise and high-rise structures should be properly followed,” says Dr Pramod Kumar Gupta, Professor, Structural Engineering, Department of Civil Engineering, IIT-Roorkee, adding that, in most cases, basic recommendations are not followed. “The used material should meet the specified requirement of fire resistance. A new version of IS 456 specifically covers different structural elements as per fire resistance.” Consider this: In Delhi, a fire broke out at Arpit Palace hotel in Karol Bagh on February 12 and a four-storey building belonging to gift store Archies on February 14. Last year, a fire broke out in Beaumonde Towers in Mumbai’s Prabhadevi, the complex where actor Deepika Padukone resides; also, the government-run ESIC Kamgar Hospital located in suburban Andheri in Mumbai caught fire. Reports revealed that the hospital contained inflammable material owing to ongoing construction work, which caught fire, and the flames spread rapidly. Also, firefighting equipment was reportedly not in place. While non-compliance of safety norms and under-equipped fire services are responsible for the sudden increase in risk posed by fire outbreaks, the use of low-quality or wrong building materials does contribute to such mishaps.Are buildings designed for seismic performance?A survey reported by the National Disaster Management Authority (NDMA) has found that in the past 25 years, over 25,000 human fatalities were caused primarily by the collapse of buildings during earthquakes (2015). Reports also indicate that the observed performance of reinforced concrete (RC) buildings is highly unsatisfactory. While a well-designed RC building should be able to withstand an earthquake of up to 7.5 on the Richter scale, during the 2001 Bhuj earthquake in Gujarat, RC buildings collapsed from an earthquake of just 6 on the Richter scale.  According to Dr Paresh Shah, Professor & Dean, Faculty of Technology, CEPT University, “Many designers do not have enough expertise for earthquake-resistant design or ductile detailing of structures; so, their designed structures may be unsafe in case of an earthquake of larger magnitude.” And, Dr Pramod Kumar Gupta, Professor, Structural Engineering, Department of Civil Engineering, IIT-Roorkee, says, “We have seen the performance of different buildings constructed at different places over the past 100 years. The intensity of earthquakes at different places is not same.”Retrofitting Existing Buildings for SafetyReal estate, residential or commercial, often tends to be an important asset when it comes to investing. However, no property is inherently protected against the elements or other aspects of nature, which makes it imperative to maintain the building after construction. “We ensure retrofitting is done at our existing commercial properties like Mindspace and Commerzone,” says Shabbir Kanchwala, Senior Vice President, K Raheja Corp. “These include upgrade of the complex and beautification of the landscape, greener campus and more environment-friendliness.” Once the MEP equipment’s shelf life comes towards its end, K Raheja Corp retrofits it with new efficient MEP equipment to enhance energy-efficiency and comfort for users. “Structural retrofit has not yet been done as our buildings are intact,” he adds. “We have made our properties resistant to earthquakes with seismic retrofitting.”Old is Gold!Select companies share with CW their oldest built structures that have stood the test of time, standing tall and strong to date.All buildings constructed by the Hiranandani Group, even those built in 1987, are safe. As Dr Niranjan Hiranandani, Founder & Managing Director, Hiranandani Group and President, NAREDCO, says,“ Lake Castle, built in 1984, still stands as one of the iconic buildings in Mumbai and a standing engineering marvel.” Having stood the test of time, the 40-mm cover to the rebars and the quality of concrete, the bones of the structure, have performed to ensure that the building serves forthcoming generations.Poddar Group has built buildings in Mumbai and Kolkata that are over 100 years old and still standing tall. Rohit Poddar, Managing Director, Poddar Housing and Development, and Joint Secretary, NARDECO-Maharashtra, says, “They were constructed using stone and motor technology in the British time and the buildings are still in good shape.”Parsvnath Developers constructed its first project, Parsvnath Plaza, in Moradabad, Uttar Pradesh, in 1997. “The design specification has been kept simple and the material used superior to get the best results,” shares Pradeep Jain, Chairman, Parsvnath Developers. “The right emphasis was laid on workmanship.”The oldest building built by Siddha Group is Jaipur Towers, in Jaipur, Rajasthan. “Completed in 1991, it is the city’s first multi-storeyed commercial building with 28 showrooms and 86 office units with an area of 100,000 sq ft,” says Samyak Jain, Director, Siddha Group. “The key to its longevity lies in its strong foundation and structural design.”Checked! RERA for QualityRERA has recently issued a circular making it mandatory for the engineers of a project to submit a quarterly review on construction quality. According to Gautam Chatterjee, Chairman, Maharashtra Real Estate Regulatory Authority (MahaRera), this is part of the RERA Act. “The Act mandates that there will be professionals who will oversee a RERA-registered project.” The architect will oversee if the designs and construction are in accordance with the planning authorities’ approvals. The engineer needs to oversee the construction work and the chartered accountant is to ensure fiscal discipline is maintained. “In addition,” he adds, “we have laid down certain laws by which the engineer will be accountable for all industry standards applicable to various input materials used in construction, and will certify that the materials used in construction adhere to the standards laid down.” This documentation will be available in projects in accordance with Section 14 (3), which talks about defect liability after the possession is handed over to the buyer. So after the possession is handed over, if an issue is raised about quality or problematic maintenance, these documents will be available to prove who is to be held accountable. For his part, Anthony de Sa, Chairman, Madhya Pradesh Real Estate Regulatory Authority, says, “One has to understand the limitations here. Madhya Pradesh RERA is not taking on the responsibility of ensuring quality. We don’t have that kind of expertise in house to monitor and ensure quality in all projects.” But he emphasises that the engineers must report on quality, and the primary responsibility rests with the builder. “In case we receive a complaint and we see substance in it, we can appoint a technical commission to visit the project and check if, in fact, quality has been maintained or not,” he adds. “We can ensure transparency and that the right person in their quarterly report has certified that quality has been maintained.” In the view of Dr Niranjan Hiranandani, Founder & Managing Director, Hiranandani Group and President, NAREDCO, this is a good beginning towards ensuring utmost precision to meet basic quality standards in construction. “It will not only bring awareness among the construction team but create a positive impact on the end-customer towards the safety of the project,” he avers. For Shabbir Kanchwala, Senior Vice President, K Raheja Corp, quality of construction has been a matter of concern when it comes to building resilient structures. “While assuring transparency and accountability, this initiative will form the basis of effective construction and enable developers to operate at high levels of productivity,” he affirms.Meanwhile, Pradeep Jain, Chairman, Parsvnath Developers, says, “There is a limitation that this may end up only as a paper exercise unless and until a policy is made for authentication of the same by an outside agency, if not by a RERA team.” And for Deepak Suvarna, Chief Projects Officer-Head Projects, Mahindra Lifespaces Developers, the success of this initiative will depend to a significant extent on the development of a periodic checking mechanism.One hopes his initiative will further enhance the growth and promotion of a healthy, efficient and competitive real-estate sector.(Read more on 'RERA- Lessons Learnt' on page 120)Dipstick on Suitable SolutionsCW conducted a brief dipstick survey among select industry experts to gauge their thoughts on probable solutions to ensure safe and healthy structures. Here are some findings:Will modular buildings or prefabricated buildings and standardisation with effective quality ratings be a solution? While some believe ‘no’, some are absolutely positive, and some think that to a certain extent this could be effective.Will mandatory certification serve the purpose? There has been absolute acceptance to this, and definitely up to some extent it will!Just like vehicles above a certain age have been asked to go off the roads, can buildings older than a certain time, unless certified as heritage, be asked to seek certification on a quarterly basis? While this is viewed as an obvious action, with people stating, ‘it has to be and, certainly, after a good number of years’ it is also believed that periodic certification should be required, say every three to five years, depending upon the age of the structure. For instance, poorly constructed buildings in extreme climates or environments can deteriorate faster. Should concrete mixes done on site attract higher GST to encourage standardisation? It is believed that this cannot be generalised as there may be specific requirements to mix on site in certain areas. In the end, ready-mix concrete is not the only answer; the water-cement ratio has to be controlled.The Heritage HeftThe quality of construction of buildings of the British era has certainly been far higher than many structures constructed by new-age developers. Complaints of leakage, cracks and the need for frequent repairs constantly plague recent developments. “Not just British era buildings, all traditional buildings were of superior quality,” says A Vijaya, Director Programme, Architectural Heritage Division, INTACH. “And this is because of the construction system and materials used.”“Sustainable practices, materials and technologies should be given emphasis,” agrees Brinda Somaya, Principal Architect, Somaya and Kalappa Consultants. “In the past, the logistics of construction were mainly handled by a single patron. But today, projects are handled by different experts. Thus, appropriate management plays an important role at all levels.”For his part, Conservation Architect Vikas Dilawari, says, “During earlier times, we were all quality-conscious and scopes were clearly defined and the best materials used. Efforts were made to ensure good details that prolonged the life of buildings.”(Read more from these conservation experts in Archi-Talk on page 112)