Connecting global expertise with local action in Indonesia

Global Buildings Performance Network; Paris; Sur place; EUR 60 000 - 80 000; Plein temps

Description du poste

GBPN global experts share retrofitting solutions from China and Singapore to turn old buildings in Indonesia into Net-Zero leaders.

In Indonesia, buildings account for 60% of the electricity use and about a third of all greenhouse gas emissions from the energy sector ( Green Building Roadmap, 2024 ). With rapid urbanization and the urgent need to cut emissions, these buildings represent not just a challenge but an opportunity. Retrofitting, which means upgrading existing structures to improve their performance, is one of the fastest and most cost-effective ways to decarbonize.

At a recent regional exchange hosted by Indonesia utility company PLN and GBPN, two experts from GBPN’s Global Network of Experts – Professor Lee Siew Eang from the National University of Singapore, Professor Hao Bin from Beijing University of Civil Engineering and Architecture – and Jackson Seng from Schneider Electric, shared insights that could be contextualized for Indonesia’s own path forward.

Here are four key lessons PLN – and any building owner – can take away.

1. Start with a clear baseline

You can’t manage what you don’t measure – it’s the cornerstone of effective retrofits. Professor Lee Siew Eang outlined a step-by-step process, beginning with a building energy performance study to establish a reliable baseline. This would enable benchmarking with best practices, identifying improvement opportunities, and mapping out remaining gaps against clear targets. Additionally, reviewing available technologies before investing, bringing in architects to design and cost before moving forward with construction are key steps to ensure an effective, well-monitored process that allows for proper evaluation of improvements.

Relying upon benchmarking and performance tools ensure that upgrades deliver real results rather than becoming costly experiments. For tropical countries like Indonesia, it is especially valuable to draw lessons from Singapore, with similar climatic conditions and where air conditioning also represents most of the building energy demand, rather than benchmarks with cooler regions.

2. Combine passive and active strategies

Designing buildings that are both efficient and comfortable require integrating passive and active strategies.

• Passive design means shaping the building itself to naturally stay cooler or brighter, so it uses less energy. This includes better facades and insulation, shading to block heat, greenery to cool surfaces, and orienting buildings for natural ventilation and daylight.
• Active design refers to the systems and technologies inside the building that directly consume energy. These include air-conditioning, lighting, control systems, and renewable energy installations like solar PV.

3. Reduce demand before adding renewables – and connect buildings with the grid

The workshop reinforced a key principle: reduce energy demand first, then complement with clean energy supply. As Professor Hao Bin explained, the path to net-zero buildings follows a simple sequence – efficiency, electrification, renewables, and flexibility.

The efficiency stage is about lowering the building’s energy appetite. Professor Hao Bin noted that today’s solutions enable building energy demand as low as 50 to 100 kWh/m2/yr through maximizing natural ventilation and lighting, installing high-performance windows, adding external shading, improving insulation, and applying high performance air conditioners.

Once demand is lowered, the next step is to electrify everything – from cooling to kitchen appliances – so the building is ready to run entirely on clean power. Only then does large-scale solar PV, small wind, or battery storage become truly cost-effective, because the systems can be smaller, cheaper, and more efficient.

But efficiency and renewables alone are not enough. Professor Bin stressed that buildings and the power grid must work hand-in-hand. In some provinces in China, for example, solar capacity has grown so quickly that the grid cannot absorb it all. The solution has been to make buildings more flexible – shifting their demand to match renewable supply. This is captured in PEDF model:

• P for Photovoltaics (rooftop solar power)
• E for Energy storage (batteries to use solar later)
• D for Direct current systems (which cut waste by running appliances directly on solar power), and
• F for Flexible demand (shifting loads like cooling or EV charging to when solar is abundant)

In cities like Shanghai and Shenzhen, thousands of buildings are digitally linked so their energy use can be shifted together – for example, dimming lights or adjusting cooling at the same time. This creates what is called a “virtual power plant,” which can support the grid as much as a real power plant would, but without burning fuel. Instead, it works by coordinating when and how buildings use electricity, making room for more renewables like solar power.

Incentives are key to encourage adoption of the technology. In Europe, off-peak renewable energy can be over ten times cheaper than peak electricity, creating strong motivation for flexible demand.

4. Keep the building ‘smart’ after retrofit

Retrofitting is not a “set and forget” exercise. Without continuous monitoring and fine-tuning, performance can slip. Schneider’s own East Asia HQ, Kallang Pulse, is a case in point. After its retrofit, the building integrated AI-assisted energy management, digital twins, and smart sensors to track usage and predict maintenance needs.

Private sector imperative

As Mr. Seng highlighted, 90% of existing buildings risk becoming “stranded assets” if they fail to decarbonize, facing potential drops in market value of up to 30%. With regulations tightening worldwide – from carbon disclosure requirements to minimum energy performance standards – retrofitting isn’t just a climate strategy, it’s a business survival strategy. Companies that act now can avoid financial risk, cut operating costs, and strengthen their brand with investors, customers, and employees.

Developing buildings with people, for people

Retrofitting PLN’s extensive building portfolio is not only about reducing costs, it is about setting a precedent for Indonesia’s public and private sector and demonstrating that building decarbonization is both achievable and practical.

The workshop underscored a clear message: with a well-defined roadmap, the right sequence of actions, and continuous smart management, even the most energy-intensive facilities can be transformed into net-zero leaders.

Another success factor underlined by all speakers resides in the need to involve the building users as much as possible and as soon as possible. A people-centred approach ensures a strong adoption and ownership of the solutions recommended. It is also a pre-requisite to ensure that building is used properly, enabling optimal operation that meets clearly defined needs.

Today, PLN is fully equipped to not only become a leader in sustainable operations, but also provide a model for other building owners across Indonesia. If PLN can chart a course toward net zero, it can inspire an entire sector to follow.

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