Futureproofing heritage: From EPC G to A+++ in a listed landmark

A listed building full of character and surprises – and now an example of a successful EPC upgrade. In the centre of Groningen, D-Groep transformed an old conference venue into a sustainable office building, going from EPC G to A+++.

Sustainability as a logical step in transformation

D-Groep is a family business active in property development and investment in the north and east of the Netherlands. Offices, housing, hospitality and retail: the portfolio is broad and the ambition clear. “Whenever we renovate or refurbish, we use the opportunity to raise the building to a high standard straight away,” explains Wibo.

The same applied to the old conference centre in the city of Groningen, which was transformed into office space. Although listed buildings are still formally exempt from EPC requirements, D-Groep deliberately chose to improve its sustainability straight away. “Once a tenant moves in, it becomes much harder to implement measures. And we all know: new legislation is coming. So it’s better to anticipate now. The demand for strong EPC ratings is also increasing, from tenants as well as through our own environmental reporting. That made it all the more important to bring the building up to a high level now.”

Careful renovation with respect for history

Making a listed building more sustainable rarely goes according to plan, and that’s exactly what makes it special. During the renovation, D-Groep repeatedly stumbled upon hidden treasures. “Every time we demolished something, we discovered surprises,” says Wibo. “Original ceilings with ornaments, hidden behind suspended ceilings. Or wood panelling from 140 years ago, which we carefully restored.”

The result is a balanced mix of history and modern comfort. “The new climate system has been subtly integrated into bookcases and deep window sills, adding comfort without compromising the building’s character. That combination is exactly what makes this project so unique.”

Visible impact: from challenge to example

The measures taken were well thought out and effective: roof insulation, new glazing, a fully electric climate system and solar panels. Wibo: “On a sunny day, the building is even self-sufficient. And you can feel the difference in the indoor climate: it’s much more comfortable now.” The impact didn’t go unnoticed. “The municipality showed great interest in the renovation process. We gave a tour to civil servants working in sustainability. There are many misconceptions around making listed buildings more sustainable, but this project proves it can absolutely be done.”

From ambition to execution with CFP Green Buildings

To realise this sustainable ambition, CFP Green Buildings was brought in early in the process. “I’d known Ilmar, energy consultant at CFP, for a while. He used to live in Groningen himself and knows the buildings well, has a feel for heritage, and understands our ambition. Together we created an overview of possible measures and their impact. That plan became our guide.”

The collaboration went beyond written advice. “Throughout the project, I regularly coordinated with CFP. For instance, when the municipality wouldn’t allow insulation of a specific wall. We’d assess the impact and then jointly present substantiated alternatives to the municipality.” According to Wibo, the cooperation with CFP was “very pleasant and meticulous. No unexpected surprises. We kept digging deeper to get the EPC.”

Ready for the future – and quickly rented out

The building has already been let, even before the renovation was finished. “It was under contract as early as November last year, while we were still deep in the refurbishment. From September 2025 it will be fully operational.”

Wibo looks back with pride: “We’ve made the building futureproof and preserved its historic character. That’s not something you see every day, and it’s something we at D-Groep are proud of.”