# Inside SMU's Hybrid Cooling Retrofit for Energy Savings

- **Source:** Stacked Homes
- **Published:** 2026-09-03T13:37:37.000Z
- **Author:** Sabrina Lee
- **Original:** https://stackedhomes.com/this-singapore-offices-4m-retrofit-could-cut-energy-use-by-20-and-pay-for-itself-in-4-years/
- **Topics:** Commercial & Industrial, Sustainability & PropTech

## Featured rationale

The project’s estimated four-year payback on its $1 million green premium could encourage more owners to retrofit older buildings under the more flexible Green Mark Version 7.

## AI summary

SMU’s $4 million Victoria Street retrofit secured a provisional SLE60 rating and is expected to save 15–20% annually, or about 500,000 kWh.

## Original article

For years, most buildings in Singapore have depended on extensive and energy-hungry air-conditioning systems to cool indoor spaces. And this dependency has increased as more high-rise residential buildings, high-quality office developments, and integrated commercial projects are built.

But air-conditioning systems are one of the major barriers in our efforts to reduce the overall energy consumption in the built environment.

That’s why I was excited to visit the administrative building of Singapore Management University, which recently completed a retrofit that saw its previous air-con system replaced with a hybrid cooling system.

Truth be told, I wasn’t exactly sure what an office building that isn’t fully air-conditioned would feel like. I imagined hot air getting trapped, making the indoor spaces feel stuffy – the typical experience with most energy-saving indoor climate systems.

But when I visited the building on Victoria Street on Tuesday, I was pleasantly surprised. The air felt light and cool indoors – that ‘just right’ feeling is rare in Singapore interiors, which are often either blasted with AC or circulating hot air.

The main office floor of SMU’s administrative building has automated lights and fans. Source: SMU.

The visit to SMU’s admin building was jointly organised by the university and the Building and Construction Authority (BCA).

The renovation and green retrofitting of the admin building was one of 26 developments that were involved in a pilot project by BCA, which has rolled out a refreshed Green Mark certification scheme – Green Mark Version 7 (GM v7).

Officially unveiled on Sept 2, GM v7 is a refresh of the existing Green Mark framework that provides more flexibility for building owners to pursue and demonstrate sustainability performance.

Some of the key changes include:

the introduction of a standalone BCA Energy Rating

a new Super Lower Energy (SLE) tier: SLE70

streamlined requirements and certification processes

Portfolio Certification

extended 5-year validity for eligible projects demonstrating sustained energy performance

The existing SLE performance level continues as SLE60, while GM v7 introduces SLE70 as a higher performance tier for projects achieving at least 70% energy savings against the stipulated baseline.

It took the team at SMU, led by Vice President of Campus Infrastructure Services, Sundar Selvam, a total of three years to get the whole building to a state where electricity costs are substantially cut and to achieve BCA’s latest low energy certification.

What is Green Mark Version 7?

Green Mark Version 7 is a refresh of BCA’s Green Mark Scheme, which was launched in 2005. In 2021, BCA launched a tailored Green Mark ratings system under the scheme, including four tiers from “Standard” to “Platinum,” based on a building’s holistic sustainability.

These criteria include energy efficiency, as well as intelligence, health and well-being, whole life carbon, resilience and maintainability.

Now, Green Mark Version 7 unveils a second rating pathway that buildings can take, which evaluates only their energy consumption, making it a more approachable goal, especially for existing buildings that can only become greener through retrofitting.

This is the “SLE70” nomenclature, which refers to “Super Low Energy” at over 70% energy savings against the building’s typology 2005 baseline. The new ranking also includes four other tiers below it in ascending order of energy savings, plus formal recognition of the use of Alternative Cooling Technologies.

The pantry room is designed to be a relaxing and collaborative space. Source: SMU

“This will enable more building owners to start their sustainability journey through energy improvement retrofits, and to progressively do more over time,” says Chee Hong Tat, Minister for National Development, who was speaking about GMv7 at the International Built Environment Week on Sept 2.

The minister says that GM v7 is intended as a more flexible and business-friendly strategy for asset owners and developers. BCA has also taken steps to streamline certification processes, including allowing owners to bundle buildings under the same typology together during applications, and extending green certification validity from three to five years.

“The refreshed framework will support our continued push towards the 80-80-80 targets, while making it easier for more building owners and developers to come on board,” says Chee.

The 80-80-80 refers to Singapore’s Green Building Masterplan, which aims for Green certification for 80% of buildings, for 80% of new developments to meet Super Low Energy standards, and for top-performing buildings to increase their energy efficiency by 80%.

These percentages are based on 2005 baseline figures, determined based on the typical energy use of buildings of the same type as of 2005.

A More Integrated Approach

The retrofit project by SMU on its administrative building covered four floors of its 14-storey building, in a process that took three years. The university says that the other floors in the building are currently under renovation in the same way.

According to Selvam, the project’s green features, which granted the glassy building on Victoria Street a provisional SLE60 rating, cost about $4 million. This figure included a new chiller plant, a new optimised Air Handling Unit, hybrid cooling with ceiling fans, LED lighting, control systems and solar panels.

However, Selvam said that this figure includes $1 million in ‘green premiums’, such as selecting more energy-efficient equipment and technology, that SMU had to invest to enable the building to achieve its certification. The university estimates that it will pay back its $1 million investment in about four years from the electricity costs it saves.

Automated blinds make it easy to adjust the amount of light and heat that is let into the building. Source: SMU

At a first glance, the floors where the green retrofitting has been completed already feel pleasant. The main office space is lined with rows of desks by a large window. There are ceiling fans throughout and LED strip lights over every row of desks. The window is partitioned into lower panels with automated blinds, and upper panels which are left blank for daylight harvesting.

According to Selvam, the team took a tailored and flexible approach, where the users’ needs were placed at the centre of the design process. This consisted of several user engagement and feedback sessions as the cooling and lighting design were being implemented.

When the team installed the ceiling fans, users reported feeling too cold because the air blew downwards. So the team tried flipping the fans upside down to blow upwards, which worked.

There are two types of sensors placed throughout the office floor. The first is a motion sensor, which controls the fans and automatically turns them off when no users are detected in the space. The second is light sensors, which face the window. These are able to dim the lights in areas where enough daylight is harvested.

Overall, it’s a delicate balance to strike between harvesting sunlight for its solar benefits throughout the day, while still protecting the cooling systems, says Selvam. In terms of the hybrid cooling, there are AC vents which are set at 25.5 degrees Celsius. That cold wind is then circulated by the fans, creating that genuinely cool feeling.

By adopting the key upgrades, including chiller plant replacement, AHU optimisation, lighting controls, solar PV installation and hybrid cooling initiatives, the retrofit is expected to deliver approximately 15–20% annual energy savings, equivalent to approximately half a million kWh per year.

Singtel and Lendlease have partnered to redevelop the telco’s headquarters into a $3 billion mixed-use development. (Picture: Lendlease)

Extending a helping hand to smaller building owners

Two more developments that took part in the pilot project of GM v7 were the new Comcentre building, which is being developed into two 20-storey office towers that achieved a Platinum rating and a Zero Energy rating.

Meanwhile, Bay South and Bay East at Gardens by the Bay have also received a Platinum rating and SLE70 rating, but got there through different means. Bay South’s biomass cogeneration system generates energy from the gardens’ organic waste. Bay East leans on passive design and a large rooftop solar installation.

Green Mark version 7 makes going green more accessible for the older guard of buildings in Singapore, instead of reserving those accreditations for new developments being built from the ground up.

The new scheme is also intended to align more closely with global ESG reporting frameworks and international sustainability standards, which will make it easier for certified building owners to access green financing and remain competitive in a sustainability-focused global economy, says Chee.

To ease the transition, BCA will provide a six-month grace period and continue to accept GM: 2021 applications until 31 March 2027. But from 1 April 2027, all new Green Mark applications, including those for building developments on land sold under the Government Land Sales (GLS) Programme on or after 30 Jun 2022, will be assessed under GM v7 only.

## Chinese translation

> Translation model: grok_cli

### 走进新加坡管理大学为节能而进行的混合制冷改造

新加坡管理大学维多利亚街大楼通过耗资新币400万元、结合混合制冷与日光感应器的改造，获得建设局更新后的绿标第7版计划临时SLE60评级，预计四年内收回成本。

多年来，新加坡大多数建筑都依赖规模庞大、耗能惊人的空调系统来冷却室内空间。随着更多高层住宅、高品质办公项目和综合商业项目落成，这种依赖还在加深。

但空调系统，正是我们降低建筑环境整体能耗时面临的主要障碍之一。

正因为如此，我很期待走访新加坡管理大学的行政楼——该楼最近完成改造，原先的空调系统已被混合制冷系统取代。

说实话，我并不确定一栋并非全时空调的办公楼会是什么体感。我想象热空气被困在室内，空间会显得闷热——这是多数节能室内气候系统给人的典型感受。

但周二走访维多利亚街上的这栋楼时，我感到惊喜。室内空气轻盈凉爽——这种“刚刚好”的感觉，在新加坡室内并不常见，这里往往不是空调开得过猛，就是热风在循环。

新加坡管理大学行政楼主办公层配备了自动照明和风扇。来源：SMU。

此次走访由该大学与建设局（BCA）联合安排。

行政楼的翻新与绿色改造，是建设局试点项目中的26个发展项目之一。建设局已推出更新后的绿标认证计划——绿标第7版（GM v7）。

GM v7于9月2日正式发布，是对现有绿标框架的更新，为业主追求并展示可持续表现提供了更大灵活性。

部分主要变化包括：

引入独立的建设局能源评级

新增超低能耗（SLE）等级：SLE70

简化要求与认证流程

组合认证（Portfolio Certification）

对证明持续节能表现的合格项目，认证有效期延长至5年

现有SLE表现水平继续作为SLE60，而GM v7引入SLE70作为更高表现等级，适用于相对规定基线实现至少70%节能的项目。

在校园基础设施服务副校长Sundar Selvam带领下，新加坡管理大学团队一共花了三年时间，才让整栋楼把电费大幅降下来，并取得建设局最新的低能耗认证。

什么是绿标第7版？

绿标第7版是建设局绿标计划的更新版本，该计划于2005年推出。2021年，建设局在该计划下推出量身定制的绿标评级体系，根据建筑的整体可持续性，设有从“标准级”到“白金级”共四个等级。

这些标准涵盖能源效率，以及智能化、健康与福祉、全生命周期碳、韧性与可维护性。

如今，绿标第7版推出第二条评级路径，只评估建筑能耗，目标更容易接近，尤其适合只能通过改造变得更绿色的既有建筑。

这就是“SLE70”的命名，指相对该建筑类型2005年基线实现超过70%节能的“超低能耗”。新评级在其之下还按节能幅度升序设有另外四个等级，并正式认可替代制冷技术的使用。

茶水间被设计成轻松、便于协作的空间。来源：SMU

“这将让更多业主通过节能改造踏上可持续之路，并随着时间逐步做得更多。”国家发展部长徐芳达说。他于9月2日在国际建筑环境周上谈到GMv7。

部长表示，GM v7旨在成为对资产所有者和开发商更灵活、更友好的策略。建设局也采取措施简化认证流程，包括允许业主在申请时把同一类型的建筑捆绑在一起，并把绿色认证有效期从三年延长至五年。

“更新后的框架将支持我们继续推进80-80-80目标，同时让更多业主和开发商更容易加入。”徐芳达说。

80-80-80指的是新加坡绿色建筑总蓝图：目标是80%的建筑获得绿色认证，80%的新发展项目达到超低能耗标准，以及表现最优的建筑将能源效率再提高80%。

这些百分比以2005年基线数据为依据，该基线按同类建筑在2005年的典型能耗确定。

更综合的做法

新加坡管理大学对其行政楼的改造覆盖了这栋14层建筑中的四层，整个过程历时三年。校方表示，楼内其余楼层目前正以同样方式进行翻新。

据Selvam介绍，这些为维多利亚街上这栋玻璃幕墙大楼带来临时SLE60评级的绿色措施，耗资约新币400万元。该数字包括新的冷冻机组、新的优化空气处理机组、搭配天花风扇的混合制冷、LED照明、控制系统和太阳能板。

不过Selvam表示，这一数字中包含新币100万元的“绿色溢价”，例如选用更节能的设备与技术，这是新加坡管理大学为使大楼获得认证而必须投入的。校方估计，凭节省下来的电费，约四年即可收回这新币100万元投资。

自动窗帘便于调节进入大楼的光线和热量。来源：SMU

乍看之下，已完成绿色改造的楼层已经令人舒适。主办公区沿大窗摆放成排工位。天花风扇遍布全场，每排工位上方都有LED灯带。窗户分为装有自动窗帘的下方面板，以及留空用于采集日光的上方面板。

据Selvam介绍，团队采取了量身定制、灵活变通的做法，把使用者需求放在设计过程的中心。在落实制冷和照明设计期间，他们进行了多次用户沟通和反馈。

安装天花风扇后，使用者反映因为气流向下吹而觉得太冷。于是团队尝试把风扇翻转朝上吹，结果奏效了。

办公层各处布置了两类感应器。第一类是人体感应器，用于控制风扇，在空间内检测不到使用者时自动关闭。第二类是朝向窗户的光线感应器，能在日光采集充足的区域把灯调暗。

Selvam表示，整体上要在全天采集阳光以获取太阳能效益、同时保护制冷系统之间取得微妙平衡。就混合制冷而言，空调出风口设定在25.5摄氏度，冷风再由风扇循环，从而形成那种真正凉爽的感觉。

通过采用包括更换冷冻机组、优化空气处理机组、照明控制、安装太阳能光伏以及混合制冷等关键升级，此次改造预计每年可节能约15%至20%，相当于每年约50万千瓦时。

Singtel与Lendlease合作，将该电信公司总部重建为价值新币30亿元的综合用途发展项目。（图片：Lendlease）

向较小的业主伸出援手

另有两个发展项目参与了GM v7试点：全新Comcentre大楼正被发展成两座20层办公塔楼，已获得白金级和零能耗评级。

与此同时，滨海湾花园的Bay South和Bay East也获得了白金级和SLE70评级，但路径不同。Bay South的生物质热电联产系统利用园内有机废弃物发电。Bay East则依靠被动式设计和大规模屋顶太阳能装置。

绿标第7版让新加坡一批较老的建筑更容易走向绿色，而不是把这些认证留给从零新建的发展项目。

徐芳达表示，新计划也旨在更紧密地对接全球ESG报告框架和国际可持续标准，从而让获得认证的业主更容易获得绿色融资，并在聚焦可持续的全球经济中保持竞争力。

为缓和过渡，建设局将提供六个月宽限期，并继续接受GM: 2021申请至2027年3月31日。但从2027年4月1日起，所有新的绿标申请，包括在2022年6月30日或之后通过政府售地计划（GLS）售出土地上的建筑发展项目，将只按GM v7评估。