Alba Iulia is a medium-sized city in the heart of Transylvania, with over 2,000 years of local history and continuous living. From Neolithic settlements near the Mureș river, to Dacian and Roman civilisations, to its role as the capital of medieval Transylvania. The city is a living palimpsest of European history.

At its centre stands the Alba Carolina Fortress, a Vauban-type star fortress begun in 1713. The biggest fortification in Romania at 70 hectares, it was never conquered. Built on the ruins of a Roman castrum and a medieval fortress, its seven-cornered star shape features three rows of defensive walls and seven gates. Inside the fortress walls, approximately 50 monumental buildings serve diverse purposes museums, cathedrals, a university, a library, and private homes still inhabited by their owners.

The entire fortress area is a historical protected area of national importance, with several UNESCO-listed sites. It is not a museum frozen in time. It is a living place where residents go about their daily lives within walls that have stood for centuries. The Living Lab inside the Vauban Fortress validates concepts, recommendations, and tools from across the MonuPED project, activating the monument-protected area ecosystem with stakeholders including building owners, monument protection authorities, energy providers, universities, and residents.

Key Challenges: Implementing Positive Energy Districts in this extraordinary setting involves three intertwined challenge areas:

Technical: The fortress is physically delimited from the rest of the city by ditches and walls, making it difficult to expand utility networks. There is no distribution network for heating, cooling, or hot water at the city or area level. Utility networks, electricity, gas, water, and sewer are managed by private companies without municipal involvement. Because the entire fortress area is protected, new utility works require special approvals and archaeological discharge. Some renewable energy solutions, such as wind turbines, are impossible; solar thermal and PV are limited to 30% of non-visible roof areas; geothermal solutions are not possible due to archaeological constraints.

Regulatory: Under Romania’s Law 422/2001 on the protection of historical buildings, any intervention must maintain the building’s authenticity and character, must be documented and reversible, and requires approval from the Ministry of Culture and National Identity, with consultation of the National Commission of Historical Monuments. Interventions are restricted not only on the monument itself but throughout its protective surrounding area.

Stakeholder: The first stakeholders to engage are the owners of historic buildings, diverse in type and motivation, from religious institutions to private homeowners. Equally important are specialists in historic building rehabilitation, whose numbers are quite small locally. All must be convinced to actively participate, starting from the practical applicability of identified solutions.