26.03.2026
First pilot opening and review of bids for energy renovation of multi-apartment buildings in Velenje with independent OSS support
On Friday, 6 February 2026, the Climate and Energy Office in Velenje hosted the first pilot opening and review of bids for the energy renovation of multi-apartment buildings within the framework of the LIFE Renov-AID project.
The initiative originated from the expert consultation “One-Stop Shop: Status and Support for Residential Renovations in Velenje”, held on 23 October 2025, where building managers were introduced to the possibility of receiving independent support for the renovation of multi-apartment buildings. One of the Velenje building managers responded to the initiative, which led to the organisation of this first pilot bid review session.
The event on 6 February therefore represented the first practical test of the One-Stop Shop (OSS) model of impartial and professional decision-support, which is being developed within the European project Renov-AID. The role of independent experts from GI ZRMK and ENSVET was not to evaluate or select the contractor, but to provide professional clarification and ensure transparency of the process for apartment owners.
Why is this important?
Renovations of multi-apartment buildings are organisationally complex. Apartment owners often face:
- unclear or non-transparent bids, frequently due to inadequate design documentation that lacks comprehensive bills of quantities,
- prices and technical solutions that are difficult to compare,
- unclear differences between proposed materials or systems,
- questions regarding responsibilities of designers, contractors and building managers.
The OSS model provides impartial professional support, helping owners understand both the bids and the process without interfering with their decision-making.
The final decision on contractor selection always remains with the apartment owners.
How did the pilot take place?
The opening of bids, which were submitted to the Climate and Energy Office rather than directly to the building manager, was conducted publicly and transparently.
Experts reviewed key elements of the submitted bids, including:
- completeness of documentation,
- compliance with the bill of quantities and tender requirements,
- technical characteristics of the proposed solutions,
- contractor references,
- guarantees and the proposed organisation of implementation.
The OSS expert opinion was provided in a descriptive format, with the purpose of clarifying the main differences between bids and helping the owners better understand the process.
The pilot as a learning experience
The bid review demonstrated how important it is to prepare the process carefully even before bids are opened. Experts particularly emphasised:
- the need for standardised and unified documentation,
- the use of locked bills of quantities (Excel files) where contractors can modify only prices but not quantities,
- a clearer distinction between compliance review, professional clarification and the final decision of the owners.
It also became clear that it would be beneficial to involve experts already in the tender preparation phase, for example when reviewing detailed design documentation (PZI) and tender conditions. According to participating energy advisors, such an approach can significantly improve the quality of decision-making, as it ensures that bids are more comparable and transparent from the outset.
Why is design documentation important?
The discussion once again highlighted the importance of high-quality design documentation, including detailed technical solutions and accurate bills of quantities. This enables the identification of optimal technical solutions already in the planning phase, helping to:
- prevent unnecessary costs,
- improve the quality of renovation works,
- ultimately reduce costs for apartment owners.
Next steps
The pilot bid review represents an important step in the development of the OSS model for transparent decision-support.
Lessons learned from the pilot will be used to further improve the model, particularly in the areas of:
- standardisation of documentation,
- more structured bid review procedures,
- earlier involvement of experts in the preparation of tenders.
Such an approach can contribute to a more transparent, impartial and trustworthy process for the renovation of multi-apartment buildings.
More about the event:
- Article in the Naš čas newspaper (in Slovenian)
- Velenje Television (VTV) report (in Slovenian)