Roof renovation KBC headquarters in Leuven

On behalf of KBC, we were responsible for both the design and project management of the energy-efficient roof renovation of their head office

Restauration & Renovation

Architect: Bureau Bouwtechniek
Client: KBC
Surface: 15,700 m² (10,000 m² flat roof + 5,700 m² roof domes)
Timing: 2021 - 2022
Status: Executed
Photographer: Group Suerickx

Energy-efficient total renovation

As part of the Leuven 2030 climate objectives, the roof of the KBC headquarters in Leuven received a thorough energetic renovation.

The renovation was part of a broader sustainability audit of the office building and included:

a complete roof renovation,
preparations for the installation of PV panels,
a rainwater study,
and the preparation of an energy-efficient roof design, including the possibility of green roofs.

The combination of these interventions contributes to a more energy-efficient and future-proof building.

Our approach

We acted as architect and technical coordinator of the project. Our approach included:

Preliminary investigation of the existing roof structure: in the process, we established that the existing cellular glass insulation was wet, requiring the removal of the entire roof package - gravel, roof waterproofing, insulation and vapour barrier - down to the supporting floor.
Preparation of the tender file with detailed plans, specifications, measurement records and estimate.
Review of bids and support in appointing the main contractor.
Site follow-up and technical monitoring of the execution up to and including delivery.

Technical details

The renovated roof structure comprises:

a new vapour barrier,
PIR insulation for optimum thermal performance,
a two-layer bituminous roof waterproofing as a durable top layer.

In addition, the entire roof was prepared for the installation of solar panels, and 1,000 running metres of natural stone façade panels and 2,000 running metres of wall coverings were temporarily dismantled, cleaned and carefully reinstalled.

Challenges

The biggest challenge was in the complexity of the detailing and accessibility of the roofs, combined with the careful dismantling and repositioning of the significant amount of natural stone trim.

KBC's head office consists of 67 roof sections that are difficult to access.

An additional challenge was that KBC employees were working in the building throughout the renovation period. Therefore, the demolition had to be done piece by piece to guarantee waterproofing and prevent leaks inside the building.

Result

A sustainable and high-performance roof that is ready for the future and meets the ambitions of Leuven 2030. Thanks to the well-considered choice of materials, meticulous site monitoring and integrated approach, this project was delivered on schedule.