# Vulnerability of Buildings to Meteorological Hazards:
## 2 Materials and Methods
### The Selection of Indicators  
#### 2.2.1 Indicators for Windstorms  
A thorough literature review of detailed impacts of windstorms on buildings led to the selection of the indicators demonstrated in Table 1. In more detail, the following indicators are considered:  
_Rood shape_: There are different types of roofs according to their shape and each one of them reacts differently to wind force. According to [PERSON] et al. [27], buildings with a pyramidal roof experience a lower uplift force in comparison with buildings with a gable or a hipped roof. However, wind characteristics (wind direction and angle) [28] as well as the slope of the roof [29] also play a role. A former window can be damaged dramatically by a windstorm if it is not protected by a shutter or with a good glazing type [30].  
_Rood material_: As far as the roof material is concerned, apparently roofs made of asphalt shingles are the least resistant to wind force, whereas metal [31; 32] and concrete roofs [33] perform better than clay or slate tiles.  
_Rood slope_: Many studies [34; 35] investigating the behavior of roofs with different declination to wind suggest that the steeper the roof slope, the lower the vulnerability of the structure to the impact of wind, setting different thresholds ranging from 20 to 45 degrees. Flat roofs are more likely to resist damage due to high wind speed, although they can still experience damage, especially along the corners and perimeter edges where wind pressure can cause uplift by the presence of eaves [21].  
_Length of overhang_: A large roof overhang can cause further damage to the entire roof due to uplift when exposed to wind loads [36].  
_Number of floors_: Several studies have shown that the height of the building may increase the wind pressure not only on the building itself but also on surrounding buildings [7; 37; 38].  
Window glazingThe type of window glazing (single, double, or triple) plays a significant role in the overall vulnerability of the building since a broken window may increase damage in other parts of the building and its interior [7; 39; 40].  
_Presence and type of shutterBased on several research studies, shutters are among the most effective mitigation/adaptation measures [41]; therefore, their presence and their type should be included in the vulnerability analysis._  
_Engineering-based state of the building:_ This indicator expresses the degree to which a building complies with the local building codes and standards. National codes may include standards associated with the connection between the roof and walls, materials used, and the foundation and lateral resistance of the building [42]. We include here three different codes related to wind according to the Austrian National Code. The codes are relate to: (a) the connection between walls and roofs, (b) the building foundation, and (c) the building lateral resistance.  
_State of non-structural elements:_ Non-structural elements such as roof components, antennas, chimneys, gutters, porches, photovoltaic panels, etc. are the most vulnerable features of a building to the impact of wind [43] due to their exposure and may increase the overall damage to the building as well as the related costs.  
_Presence and state of the balcony:_ The existence of balconies and the type of protection (shutter, glass, no protection) contribute significantly to the overall vulnerability of the building [44].