In 2022, enercity’s district heating sales team processed around 60 customer inquiries a year. Today, that number has grown to more than 2,000.

For one of Germany’s largest energy providers—serving nearly a million people with electricity, heat, gas, and water—this spike in interest in sustainable heating exposed a digital gap. There was no centralized view of the district heating network and customer request.

Low-code, and ultimately Mendix, provided the solution. What began as an effort to streamline sales processes evolved into a unified digital backbone connecting customers, partners, grid operations, and internal teams. Centered on a shared, map-driven view of the network, the platform brings customer inquiries, infrastructure data, and operational workflows into one place, giving enercity full visibility today and the flexibility to evolve as demands continue to grow.

A Map as the Foundation for Digital Transformation

District heating is inherently spatial. Pipes run beneath streets. Capacity depends on network topology. Customer eligibility is determined by proximity, not just an address in a database.

The team had one non-negotiable requirement: a network-wide, map-based view of the entire district heating infrastructure. Before Mendix, that perspective simply didn’t exist. Sales teams manually stitched together information from emails, spreadsheets, and disparate systems, slowing response times and limiting strategic planning.

What began as an effort to improve sales efficiency quickly evolved into something far more ambitious: a shared digital map that would serve as the backbone for district heating sales, network planning, and cross-team collaboration.

In 2024, enercity launched this initiative in partnership with d.u.h. Group, whose experience with similar projects helped translate that vision into a scalable, future-ready platform.

Building a Scalable Sales Foundation

Demand for district heating had exploded in just a few years, and Mendix became the backbone to make enercity’s operations more transparent and efficient.

“They realized scaling the team from four to fourteen people wouldn’t be enough without better processes and tools,” shared Marc Scheil, a project manager at d.u.h.Group.

At the center of the new Heating Sales App is the interactive network map. Every customer inquiry now starts, and stays, there.

1. Potential customers submit a contact form
2. The platform visualizes the request on the district heating map
3. Network eligibility is checked instantly
4. Sales teams generate offers based on real infrastructure data

Data migration was a key challenge at the start.

To accelerate development, enercity leveraged several Mendix Marketplace modules, including data import, document generation, email automation, secure authentication, and deep links for anonymous customer interactions.

Users can now see customer status, current heating systems, and planned connection timelines—providing a visual, centralized overview that unifies workflows and supports strategic planning.

“User feedback has been central,” shared Leon March, Business Account Manager at enercity. “For example, users suggested managing each product individually rather than a combined view. We implemented that change quickly, which made the overview much clearer and easier to use.”

Development ran from December 2024 to June 2025, and the results speak for themselves: data retrieval now takes 2–3 clicks, productivity has improved by 10–20%, and teams can make more informed strategic decisions.

enercity is now expanding the platform to support field teams with smartphones and tablets. “The next sprint will allow sales staff to record customer information on-site, take photos of entrances, and provide immediate input for infrastructure planning,” Marc explained.

Extending the Digital Backbone

As the district heating platform matured, enercity began applying the same low-code approach to other areas of the business.

“With growing volumes and stricter regulatory requirements, we needed processes that were just as transparent and flexible for partners as they were for our internal teams,” March explained.

The result was a series of connected applications—each different in purpose, but all built on the same digital backbone.

The Sales Partner Portal (VPP) centralizes collaboration with internal and external sales partners. Partner management, contract handling, tariffs, quality assurance, and commission settlement are now managed in a single system. Standardized communication and clear workflows have:

• Reduced errors across the board
• Accelerated processing time
• Improved transparency for all parties

For installation companies, Commissioning Orders (IBA) provide guided, click-through workflows for submitting meter movements across electricity, water, gas, and district heating. Case handlers review and manage these requests in Mendix, while workflows can be adjusted independently to reflect new business or regulatory requirements.

The enercity NetzPortal (eNP) serves as a central digital entry point for grid customers so they can:

• Register PV systems
• Request new house connections
• Manage controllable consumer appliances
• Complete intelligent metering processes end to end

Together, these applications extend the same principles established in the district heating platform: shared visibility, clear workflows, and scalable digital processes.

“Overall, there’s huge potential for future projects,” Scheil emphasized.

Building an Internal Development Team

Collaboration and continuous improvement are central to enercity’s low-code journey. From the outset, close cooperation with d.u.h.Group helped shape not only individual applications, but also the way Mendix development is organized across the company.

“Working with d.u.h.Group wasn’t just about delivering applications,” March shared. “They helped us establish best practices and a way of working that our teams can now carry forward independently.”

Regular workshops bring together Mendix teams across the organization to align processes, share lessons learned, and identify opportunities for reuse.

With ongoing guidance from d.u.h.Group, enercity’s development is faster, consistency is higher, and teams are increasingly empowered to contribute across projects.

Looking Ahead to Field Innovation and AI

With Mendix embedded in daily operations, enercity is turning to next-generation capabilities that extend beyond the office.

“We’re equipping field teams with tablets for on-site customer meetings,” March said. “They can assess basements, take photos, annotate details, access data, and submit information directly into the system.”

Photo capture, annotation, and AI-driven insights will further enhance planning and decision-making. AI will help surface patterns in complex datasets, highlight priorities, and make information easier to access.

“The goal is to handle very complex data, making it easier to access information that isn’t straightforward to report manually. This feature is designed to support our sales team, helping them understand where to focus their efforts. For example, they could quickly see the status of contracts or other important metrics. It’s a supportive tool to make their work more efficient and informed,” March added.

New projects are now primarily built in Mendix, helping enercity reimagine the entire customer experience.