## 4 Strategies and Solutions  
The strategy implemented in this project was first to study the building in a non-invasive way via the use of the above-mentioned studies (thermal calculations, indoor measurements, and thermal camera photos). Identified SolutionsTaking into consideration the energy audit and the in situ studies, a series of solutions were identified as proper for the intervention. They are as follows:  
* Proposed solution 1: Changing the entire window as a result of the minimum thermal resistances provided for the external window frame (R'min > 0.9 m\({}^{2}\)K/W);
* Proposed solution 2: Keeping the wood frame with restoration measures but replacing the glass with a high-performance example, namely, 4-12-4 type with low-e. After changing the windows, the following must be taken into account:
* The sealing of cold air infiltrations in the joints of carpentry contours between the skirting board and the wall gap with a sealing film on the outside (width 29 cm), and filling the remaining spaces after installing the new windows with polyurethane foam and closing the joints with plaster;
* The water-repellent sealing of the joints on the outer contour of the frame with special materials (silicone putty, exterior sealing film, hydrophobic mortars, etc. ), as well as covering the joints;
* Where necessary, replacing the existing galvanized sheet joists on the external horizontal gable at the bottom of the wall gaps with aluminum gables; the slope, the existence and shape of the teardrop, the sealing against the frame (nails with a wide head at small distances), the sealing against the wall (the edge of the board raised and covered with plaster on the upper part), etc., will be ensured;
* The unclogging (or creating, if there are none) of the holes at the bottom of the skirts intended for the removal of condensed water between the sashes. The thermal modernization of the exterior window frame is proposed to be carried out in the following manner: changing the entire glazed surface with glass of type 4-12-4 energy performance to prevent the building's cooling requirement from increasing during the hot season; the solar coefficient of the glass will be g < 0.35. Adopting the solution of the total replacement of the existing windows involves sealing the interior space and drastically reducing the number of air exchanges below the value necessary to dilute the CO\({}_{2}\) concentration and indoor humidity. Thus, before the rehabilitation, the air exchange was partially achieved through the leaks in and around the window frames. In addition, by providing sealing gaskets, air freshening must be conducted in other ways, namely, by installing hygro-adjustable grid systems in the color of the wooden frame. The solutions identified for the doors at the entrance of the building are to be equipped with automatic, mechanical, or electric closing systems. For the door at the main entrance, it is recommended to choose a configuration similar to the existing one, consisting of two successive doors between which a buffer space from the outside environment is created. The rehabilitation solutions chosen for the attic slab include insulating the floor towards the unheated bridge; the heat-insulating layer will be applied to the outer face of the support layer after uncovering the ballast and/or waterproofing layers as appropriate. The hydrothermal insulation solution will be made with a layer of fireproof mineral wool of a minimum 30 cm and a maximum conductivity of 0.04 W/mK. Regarding the modernization solutions proposed for the interior lighting, the proposed strategy was to replace the interior lighting luminaires, which currently have fluorescent lamps, with efficient LED lighting luminaires. The increased efficiency of LED luminaires would lead to energy savings and therefore the achievement of another desired outcome. Also, their average lifetime is substantially longer than any classic source, operating for up to 30,000 h without the luminous flux diminishing.