**2. Case study**

*"The houses that are capable of proposing this decisive encounter are, without any doubt, great architecture. AND, like all successful models, they have a broad and mixed* 

**Figure 1.** *Casa Sommer – 3 D model (Geostar, levantamentos arquitetónicos).*

*Structural Consolidation of Architectural Heritage DOI: http://dx.doi.org/10.5772/intechopen.99602*

#### *ancestry where art permanently intersectswith the life(s), which is another noble functionof architecture"* [2].

The case study presented evaluates an important 19th-century example of private housing construction – Casa Sommer (**Figure 1**), in the heart of the historic center of Cascais, Portugal, simultaneously combining two trends - romantic and neoclassical, two most relevant stylistic currents at the international level of the 19th century.

As main characteristics of this type of architecture, it stands out its orthogonal lines, the regular, geometric and symmetrical shapes as well as the columned portico. Consisting of an almost quadrangular plan (10.24x11.73 m), with three overlapping floors, with an approximate area of 132.00 m2 per floor, shown externally on the facades through cornices that form architraves. Its verticality is assumed by the elevation of 2.60 m of the noble floor in relation to the street, imposing itself in this way on the public square.

The vertical communication between the different floors is ensured by the staircase strategically placed under the transversal axis of the building, in which the openings in the east façade ensure the natural lighting and ventilation of the interior space. The portico of columns with a square shaft, based on a square base, supporting the porch balustrade in stone, imposes the main entrance of the House.

#### **3. Structural characterization**

#### **3.1 Exterior and interior walls**

The building was built from an almost quadrangular base (10.24x11.73 m), a geometry that gives it favorable performance in terms of seismic behavior. The outer walls were built in irregular masonry of two-piece stone, cut out on both sides and with horizontal paneled orientation, of the type of masonry with mortar joints, filling the inner core with smaller stones [3]. In this constructive typology, the stones are laid on top of each other - in a joint forest, wrapped in lime and sand mortar - usually at the time with a 1: 2 line, in which ceramic shards and stone frames are transversely inserted in order to fill the gaps. Empty spaces, giving not only better adherence of the elements but also allowing the execution of regular beds for the laying of successive layers.

The walls are supported by direct foundations, in a simple extension of them with widening already in the ground, of identical constructive composition. The thickness of the wall is variable: 0.75 m from the foundations to the level of the landing of the front staircase; 0.65 m from this level to the threshold of Floor 2; 0.60 m in the outer envelope of Floors 2 and 3.

The start of the cornerstones in the form of pilasters, aims to increase their area of contact with the terrain and consequently an improvement in the distribution of loads, takes on a projection resulting from the difference of its base geometry of 1.00x1.00 m, from the foundations to dimension of the level of the frontal staircase, from here it is reduced to 0.80x0.80 m. It was common for lime mortar to be applied to the plaster 1: 3.

The renders were executed in successive layers, thus managing to minimize the cyclical effects of the contractions / expansions to which the different materials are subjected, considerably increasing the durability of the work as a whole. The interior walls of the Ground Floor (**Figure 2**), are also made of irregular stone masonry, completely identical to the typology of the exterior walls, with the exception of the thickness which is 0.40 m thick, forming the start of the stairwell and the support of the walls of the axial corridor of the house, give the necessary stiffness to the general foundation of the building.

The interior walls in wooden partition (**Figure 3**) of the remaining floors have not only the usefulness of compartmentalization of spaces but also the function of structural locking of the building *"in the old buildings they almost always play a structural function of relief, since the building itself the architecture of the buildings, the organization of the spaces and the structural limitations of the available elements cause the resistant capacity of most of the walls to be mobilized* "[4].

The partitions made up of a structure made of wooden cones, in a set of vertical, horizontal and diagonal pieces - crosses of St°. André (**Figure 3**),

**Figure 3.** *Wood partition wall structure.*

*Structural Consolidation of Architectural Heritage DOI: http://dx.doi.org/10.5772/intechopen.99602*

carved and nailed so as to allow them to fit simultaneously with each other and with the braces, establishing the connection to the floors. The horizontal lath of trapezoidal section, also in a little house, serves as a support for the plastering of weak sand mortar and aerial lime, whose usual feature at the time was 1: 3, (weak retraction and weak mechanical resistance, giving good adhesion to the base and good workability) [5].

#### **3.2 Floors**

The structure of the pavements of the raised floors is composed of elements in white wood, applied in the form of Portuguese-style flooring, with a thickness of 0.03 m and a variable width (0.12 / 0.15 m), resting on beams with 0.17x0.08 m arranged in the direction of the smallest span, built into the outer walls, with a distance of 0.36 m from each other (**Figure 4**).

#### **3.3 Roofs**

The roof is made of white cone wood, with symmetrical hipped roof, with a structure made up of two trusses, fixed to the crevice existing in its perimeter, interconnected by bars and slats to support the ceramic tiles (**Figure 5**).

The structural typology of the roof, together with devices for connection to the exterior walls, using metal parts called bolts (**Figure 6**), anchored on the outer side of the wall, in the transverse direction of the beams, as a whole guarantees the necessary bracing of the building [6].

**Figure 4.** *In situ survey of the wooden floor structure.*

**Figure 5.** *Wooden structure of the roof.*

**Figure 6.** *Metal bolt.*
