We must meet the needs of people today, but without compromising the wellbeing of humanity in the future. That’s the central theme of the sustainability agenda. And it applies to the construction sector perhaps more than anywhere.
Take climate change as an example. According to the World Green Building Council, construction accounts for nearly 40 per cent of the world’s total carbon emissions. A quarter of this is released during the process of construction and material manufacturing, while three quarters is released during the operation of buildings.
But sustainability isn’t just about climate change. It also involves the management of scarce natural resources, the avoidance of pollution, the encouragement of biodiversity and the promotion of human health and wellbeing.
The construction industry has a part to play in all these areas, by transforming the way the built environment is designed, constructed, operated and ultimately redeveloped. And no part of the construction sector is more important here than mechanical, electrical and plumbing (MEP) systems.
The importance of MEP in construction
MEP systems are at the heart of any sustainable construction project. While it is largely structural considerations that impact the safety and longevity of buildings, MEP systems define the energy and water that a building uses and the impact it has on the environment.
Mechanical systems include air conditioning, air quality (including humidity, an important parameter for managing Covid-19), hot water provisions, and smart building management systems. Heating, cooling and air quality in particular account for a large proportion of the running costs of a building.
Increasingly new materials and techniques are being developed to decrease the load of HVAC (heating, ventilation and air conditioning) systems. Solar, wind and geothermal energy sources can be integrated. New forms of glass can generate electricity or automatically cut out sunlight, reducing heat load. Energy Recovery technologies are also available, which can be segregated as ECM and EEM, i.e. Energy Conservation Measures and Energy Efficiency Measures. Reducing use of energy with smart systems that respond to external conditions and internal occupancy is part of ECM; while implementing the cogeneration concept of utilising the heat released by air conditioning for heating domestic water can be termed as EEM.
But it is not just technology that has an impact. Sophisticated design is also critical. The aspect of buildings and the placement of windows and doors will affect power requirements. The colour and nature of building surfaces can have an impact by reflecting or absorbing solar energy. And something as apparently simple as planting around a building can have an impact: medium or big-sized vegetation not only provides shade to walls and windows, but also cools the ambient air through evapotranspiration. Also, the orientation of glass facades based on the location of the project can also have a great effect.
There are sophisticated trade-offs to be examined here. For instance, making buildings airtight can have a positive effect on power requirements in some circumstances, but this may, or may not, be outweighed by the cooling properties of increased ventilation.
Efficient electrical systems, based on the energy usage patterns of permanent and temporary occupants, are equally important for sustainability. Systems to recycle surplus electrical energy from, say, solar power into batteries or back into the grid, reduce the total cost of electricity. Smart building controls can moderate lighting or air conditioning costs depending on the room or corridor occupancy.
It’s important not to forget plumbing. As climate change takes effect, it is likely that water will increasingly become a valuable commodity, as it already is in certain parts of the world such as the western parts of Asia. Here, recycling water within a building is an important consideration, as it can then be reused for washing, flushing, or watering plants. The harvesting of rainwater is also immensely valuable.
Together, well-designed MEP systems can have a considerable impact on the running costs of buildings. One example is a 32-floor office block in Dubai where advice from our MEP consultancy, Consistent Engineering Consultants enabled the cooling load to be reduced by 24 per cent. This was made possible by a detailed re-evaluation of planned electrical equipment and lighting, and by redesign that affected cooling loads, fresh air requirements and air infiltration. Changes to occupancy plans also yielded substantial savings.
Another example from Consistent is the development of a ‘Sustainable villa’ with Nearly-Zero Energy requirements. A number of tactics were employed to achieve this: the aspect of glass in the building was chosen to reduce heat transfer; insulation and air-tight construction further reduced heat transfer, and reflective paint also dissipated unwanted solar energy. Instead, the energy requirements of the building were minimised through the incorporation of solar panels and an energy recovery system. Costs for this type of building, which could also be employed in larger developments including high-rises, are coming down rapidly. The incremental cost of sustainable building techniques like these should be 12% or less. It is likely that this type of approach will become the norm in the future.
Efficient MEP design goes beyond creating sustainable buildings. These will normally be far less costly to run, thanbuildings designed without a sustainable approach. But well-planned MEP also contributes to the development of “WELL buildings” that promote the nourishment and mental health of occupants and contribute to productivity, good teamwork and lowered stress levels.
If that seems fanciful then consider how smart lighting contributes to security, and to the feeling of security, how comfortable working conditions such as an absence of cold draughts or distracting noise contribute to employee engagement and concentration, and how sanitary conditions, clean air and low humidity contribute to physical health.
The reality is that these specialized building designs require specific expertise. For instance, Consistentemploysgreen building professionals who are LEED Accredited and health and safety professionals who are WELL Accredited.There are many other international and regional-level accreditations for energy and sustainable building accreditations that can be earned. Requiring their engineers to hold these allows consultancies to cater to a wide range of projects that aim at addressing all three parameters of sustainability- Environmental, Social, and Economic.
Budgets and other constraints
Of course, sustainable design generally comes at a cost. And while the cost is far lower than it once was – a typical cost uplift might be in the region of 10 to 15 per cent – it is always necessary to work within budgetary constraints. However, the cost of more expensive materials is frequently offset by other capital expenditure. For instance, a well-insulated, airtight home may need lower capacity HVAC units. And these capital savings are of course in addition to savings in the form of long-term running and maintenance costs.
There may be other practical constraints. The geography of the development, security concerns, or local regulatory requirements may preclude certain options such as a shaded aspect for the main entrance, geothermal heating or cooling, wind power or large areas of glazing at ground level. Sustainability is only one concern for the built environment, albeit a very important one.
One well-established approach to managing constraints is to undertake an energy audit. Consistent, for instance, has a specialist Energy Division with certified energy professionals who handle this. In the case of existing buildings, a basic audit can identify low-cost measures to reduce energy consumption: LED lighting fixtures, sensor-based intelligent lighting control, low-flow water fixtures, and the cleaning and maintenance of equipment. Such measures may have a short payback period.
Additionally, consultants can also carry out more comprehensive audits that can suggest deeper retrofitting solutions, which will decrease the energy consumption and operating costs drastically, albeit with a longer payback period.
Some consultants such as Consistent can work on an Energy Performance Contracting (EPC) model, where the client does not need to invest capital for audits and retrofitting. These are carried out by the agencies at their own expense. Once operational, the savings in energy bills for the client are then shared between the agency and the client for a fixed number of years. However, the legal framework needs to be well-established to safeguard the interests of both parties.
Building a better world
Recognising the business benefits of sustainable construction, including cost, quality, employee engagement and brand reputation, we can make the case for a more sustainable future. Envisioning a future in line with the UN’s Sustainable Development Goals, we must combine vision with practical action- assembling construction partnerships with the right skills- and deliver designs that safeguard our environment.
The world is moving towards a future that looks more challenging than today. We have been responsible for this change. We need to make this planet a better place to live, today and for future generations. And we can achieve this by taking inspiration from our sustainable past.
Our ancestors’ approach to development was based on the fundamental concepts of sustainability. The Ancient Civilizations chiefly developed in areas where the overall harmony with nature could be achieved.
Over the last two centuries, three Industrial Revolutions have helped us achieve great comfort and progress; but that has been at the cost of the planet and its invaluable resources. Now, it is time to realign our thoughts and actions to re-establish balance between human development and nature, and build a better world.
Mr. Sagar Kulkarni is the Founder and MD of Consistent Engineering Consultants, an MEP and Consultancy headquartered in Dubai, with a regional office in Mumbai. Having founded Consistent in 2007, he has led his team to around 500 successful projects in the Middle East, India and Africa regions.
Having a number of international certifications to his credit (see above), he is a member of ASHRAE, the US Green Building Council, and the Emirates Green Building Council. With an experience of over 25 years, Sagar is a strong advocate of green building and has been a speaker and expert panelist at various global events in the UAE, Saudi Arabia, Oman and India.