## 3 Case Study: Campulung Town Hall Building
### Identified Building Problems before the Intervention Process  
The main reason why the building needed to be optimized energetically was the fact that this heritage building has a public function, as this is the location of Campulung's Town Hall. In terms of problems, the building was dealing with high energy bills, unoptimized energy usage, thermal bridges, and interior spaces that could not be utilized as they had not been rehabilitated; hence, the administration decided to modernize the building, making it more accessible and user friendly while also being able to produce its own required energy. Currently, the building faces significant energy efficiency challenges. It is primarily heated through an outdated central heating system, leading to high energy consumption and inefficiency. The building's heating system is centralized and relies on a single gas boiler located in the basement. This boiler operates at high temperatures and distributes heat through water radiators set at 80 \({}^{\circ}\)C. The conventional arrangement, albeit prevalent in older buildings, presents efficiency obstacles and sustainability issues due to its elevated energy usage and substantial heat dissipation.  
The thermal performance of the building is compromised by several factors, including poor insulation in the attic, single-glazed windows, and significant air infiltration through aging window frames and doorways. These issues are enhanced by the building's large volume and high ceilings, which makes it difficult to maintain consistent indoor temperatures.  
The thermal envelope of the structure is the main emphasis of the suggested energy optimization techniques. Among the main procedures meant to lower energy consumption while maintaining the architectural integrity of the building are replacing the window units with double-glazed panels, adding better sealing and insulating materials in the attic, and installing more-efficient heating systems. Along with enhancing the Town Hall's sustainability, these actions are supposed to act as a model for the preservation of other historic structures dealing with comparable issues.  
The exterior walls of the building are made of 45 cm solid brick. The construction is provided with unheated space with a hipped roof. The floor above ground is made of concrete and does not have any thermal insulation in the soffit. The perimeter plinth is not thermally insulated. The joinery of the exterior windows and doors is made of wood. The heels are positioned on the inner face of the parapets.  
Figure 4: Town Hall of Campulung, Romania—side building facade.  
The existing exterior finishes show mechanical wear at the level of the visible layers. Due to atmospheric agents, mechanical agents, and biological agents, as well as occasional rheological phenomena, the finishes have been affected up to now by dirt and discoloration caused by the action of ultraviolet rays, stains, etc. The building has no special shading elements on the facades.  
As can be seen in the image above (see Figure 5), the state of the attic was unkept and no intervention was conducted to insulate the roof space, hence the occurrence of substantial heat loss and thermal bridges.  
However, because the attic had not been in its original form since the building's construction in 1934, this necessitated proper care and proper rehabilitation solutions so as not to lose the historic and architectural value of this interior space, while also enabling us to implement certain changes to the space to incorporate the HVAC elements to properly generate energy efficient results for the building.