How does retrofitting make buildings more sustainable?
A well-planned retrofit approach can make a building’s performance more efficient and sustainable
The building sector and the MEP industry stand at an inflexion point. Green building certification, either enforced through regulations or otherwise, is increasingly becoming the norm. One could ask: “are buildings really becoming more sustainable due to certification at the design and development stages?”
However, the more critical question is: “how do we convert the existing stock of business-as-usual buildings to green buildings through retrofit?” It would be interesting to conduct research and analysis on certified green buildings in order to assess if these are indeed meeting the sustainability goals that they were set out to achieve, and if not, how far deviant they are. However, given that certified green buildings in the UAE are only a few hundred, the next frontier is to convert/upgrade the ‘non-certified’ building stock to green standards.
Undoubtedly, design stage green building certification resolves substantial sustainability issues. For instance, the usage of LED lighting in order to achieve lighting power density under Ashrae 90.1 Energy Standard for Buildings has the potential to reduce energy consumption by up to 90% and is, for practical purposes, a one-time job.
However, other MEP systems like energy-efficient HVAC equipment (chilled water systems, VRFs, FAHUs with heat recovery etc.), BMS, sensors (temperature, humidity, CO2, occupancy etc.), monitoring devices etc. are not necessarily one-time projects. One needs to understand the role such equipment and systems in a building are playing, to make buildings sustainable throughout their life cycle and how we can make them more effective.
Sensors and monitoring devices are peripheral field devices, whose data determine how a built-environment operates. Incorrect data leads to inefficient operation of MEP equipment. This can not only lead to higher energy consumption, but also to compromised indoor environmental conditions that directly result in sick building syndrome and lower productivity of occupants. Therefore, these devices require regular calibration, replacement and upgrade when necessary. HVAC equipment and BMS need continuous commissioning and regular re-programming.
Consequently, building owners and occupants need to adopt a different approach to ensure that buildings either remain sustainable or become more sustainable throughout their life cycle. While a retrofit model like ESCO is good in principle, this needs to be a secondary step for buildings. The first step is having good housekeeping practices and a sustainable retrofitting policy in place.
Buildings continuously undergo retrofitting, for one reason or the other. Ensuring these retrofits are carried out in a manner that organically enhances a building’s performance is an easy first step. Sustainable procurement practices without being noticeable can seamlessly convert inefficient buildings into highly efficient ones over a period of time. Sustainable procurement should cover a wide range of retrofitting ranging from replacement with LED lamps to Emirates Authority for Standardization and Metrology (ESMA) labeled five-star equipment.
Increasingly, landlords of buildings with their own HVAC plant need to consider integrating chiller plant performance objectives into maintenance contracts. If a building already has a proper annual maintenance contract, the current approach is “maintain equipment for no occupant complaints”, and rarely for “maintain equipment for low energy consumption”. This approach needs to change completely and this is possible through a combination of appropriate KPIs in FM contracts, ensuring maintenance personnel are qualified by the manufacturer and ensuring appropriate monitoring devices (for kWh, kW/TR, etc.) are in place and calibrated regularly. For buildings with chiller plants above a certain age, landlords need to consider chiller plant replacement in order to reduce energy consumption. While such retrofit/replacement could be heavily capital intensive, the ESCO route could mitigate the financial challenge.
Eighty percent of installed BMSs do not function properly – a statistic shared by a top authority a few years ago. Even fully functional BMS are rarely operated properly to achieve energy efficiency. BMSs rely on sensors and devices, as well as appropriate logical programming to ensure energy consuming equipment are operating in a way that reduces a building’s energy footprint without compromising indoor environmental quality.
In order to deliver efficient energy consumption, it is imperative not only to maintain the BMS but also operate it effectively through ongoing re-programming that must work in tandem with weather patterns and occupancy patterns, while synergising with free site resources.
Retrofitting a BMS with latest software upgrades, calibration of sensors and devices, as well as expanding the outreach of the BMS through additional field devices, backed by result-oriented annual maintenance contract and ownership of efficient operation, have the potential to significantly enhance operational efficiencies of buildings. The necessary capex and opex needed for such retrofits can easily be recovered through achieved energy savings and can be built into the annual O&M budgets of a building. In case a complete replacement of the BMS is necessitated, an ESCO model would perhaps be the best way to implement such retrofits.
To summarise, we need to shift from a “retrofit only when unavoidable” approach to a “retrofit as an ongoing philosophy” approach. Much like planned preventive maintenance, a well-planned retrofit approach can make a building’s performance more efficient and sustainable, both financially and environmentally.
Sougata Nandi is the Founder of 3e Advisory, a firm that specialises in setting Cleantech start-ups on a sustainable business model. Sougata was the second LEED AP from the UAE in 2005, led the Green Building movement in UAE by delivering six of the first 12 LEED certified projects and also led the Emirates Energy Star program between 2011 and 2013.