The case study that determined the present research is the restoration of one Transylvanian wooden church from Cojocna, Cluj county, Romania. The original design (2018, Aqua Prociv Proiect Romanian company's project) assumed all ICOMOS's charters and the recommendation from this area in quality design, and it is in the stage of the execution auction. After nowadays standards, the restoration work does not need to achieve any form of energy efficiency, and its primordial target is the preservation of historical values and many other essentials for Humanity.
The risk of museification of the heritage buildings with this architectural function, church, can sustain different and relevant points of view about the restoration, as could remark in the Leeuwarden Declaration (23 November 2018). There are some essential theoretical concepts linked or not to this specific domain, as art, history, or philosophy, otherwise that can sustain the potential of this kind of intervention. The insertion of new materials in heritage works is not in the current practice of restoration. However, there is a need to adapt to the in changing world and within his changing needs—evaluation on the evolution of some building parts in the context of the technological revolution. We propose a study for the change of finishing roof material with the maintenance of the roof geometry or structure. The new material is the PV solar roof tiles. The numerical values for electrical energy produced with photovoltaic technology will appear evaluated with a homemade computer program validated by comparison with dedicated software (PHPP_V9.6; PVsyst 6.8.6). Other arguments from theoretical and more subjective points of view will also notice.
Conclusion: The research started in the nowadays context from the sustainability area, and one question that appears natural was about how close to regenerative design can be achieved through restoration works.