Journal of Sustainable Architecture and Civil Engineering 2018/2/23 16 Corresponding author: jcardoso@ubi.pt Haussmann Structural Floors Repairs and Strengthening Techniques Received 2018/08/17 Accepted after revision 2018/09/26 Journal of Sustainable Architecture and Civil Engineering Vol. 2 / No. 23 / 2018 pp. 16-24 DOI 10.5755/j01.sace.23.2.21426 Haussmann Structural Floors Repairs and Strengthening Techniques JSACE 2/23 http://dx.doi.org/10.5755/j01.sace.23.2.21426 Rui Cardoso C-MADE, Civil Engineering and Architecture Department, Beira Interior University 6201-001 Covilhã, Portugal Introduction Haussmann buildings architecture spread throughout the city of Paris. Those buildings were constructed in the 19th century, being now centenarians. However, they present several pathologies which prevent their adequate use, moreover, an update regarding users security, sound, thermal and fire requirements is, among others, urgently needed. Additionally, there is actually, in Paris, an increasing demand for hotel rooms. For those previous reasons, Haussmann buildings are nowadays submitted to heavy operations related to use change, conservation, and rehabilitation. In this paper, repair and strengthening techniques used in old timber and metallic floors and retaining a great amount of the original structure are introduced. This presentation is the result of a technical survey realized during a heavy rehabilitation operation which takes place between 2015 and 2017 in a Haussmann building complex located at La Madeleine. The knowledge from this study could be very useful for the development of sustainable rehabilitation and strengthening techniques, aiming to preserve this important building heritage or similar ones existing in other countries. Keywords: floor rehabilitation, Haussmann buildings, strengthening, structural characterization. A huge quantity of rehabilitation and strengthening works are being realized actually in Paris Haussmann buildings. In fact, those buildings being old, since built or rebuilt around the 19th cen- tury, present nowadays a very poor state of conservation and several pathologies affect their main structure. Furthermore, the environmental issue related to energy consumption for cooling and heating make them obsolete. Beyond that, the Haussmann buildings are representative of the Paris architecture, (Jombert C.A., 1764), (Froidevaux Y., 1986), (Lepoutre D., 2010), (Jordan D.P., 2015) since all the city is based on that architecture, which was used until the introduction of con- crete and steel in the 20th century. It is of vital importance to preserve and protect this legacy and demolition can´t be a solution. Furthermore, there is a huge demand for hotel rooms in the city of Paris due to a growing tourism activity. All the reasons present previously justify the urgent need to realize rehabilitation and strengthening works. This scenario related to traditional building her- itage state of conservation is not unique and can be found in several European countries, (Branco J. et al., 2006), (Catarig Al. and Kopenetz L., 2007), (Cardoso R. et al., 2015, 2016, 2017). This article characterizes the strengthening techniques applied to the floors of a Haussmann building com- plex located at La Madeleine, based on information gathered during the rehabilitation works that were performed between 2015 and 2017. This complex is located at La Madeleine near the Saint Marie Madeleine Church. Fig 1-a) shows an aerial view of the complex implantation and Fig 1-b) shows a front view of the existing facade. 17 Journal of Sustainable Architecture and Civil Engineering 2018/2/23 The Haussmann floors This article is original because the technical obser- vations were made during the rehabilitation working stage, by the author, which was simultaneously the strengthening project designer. Proper investiga- tions were realized in the existing superstructure, on the foundations and particularly in the floors structural elements, before and after strengthening. Complementary, an assessment of the geometric characteristics of the structural floor elements was realized. Resulting in a step description of the floors strengthening technique used. We strongly believe this paper will allow to better un- derstand the actual floor strengthening construction techniques which minimize the introduction of new elements, (Tuba Sari, 2017) (Akadiri P.O., 2012), al- lowing further studies related to numerical modelling, heritage rehabilitation and strengthening and also sustainability issues. The organization of the paper is the following: firstly the Haussmann building complex is defined, secondly, the metallic and timber floors are described and the strengthening techniques are ex- plained. Finally, some conclusions are indicated. Fig. 1 The Haussmann building complex a) Aerial view b) Front view geometric characteristics of the structural floor elements was realized. Resulting in a step description of the floors strengthening technique used. We strongly believe this paper will allow to better understand the actual floor strengthening construction techniques which minimize the introduction of new elements, (Tuba Sari, 2017) (Akadiri P.O., 2012), allowing further studies related to numerical modelling, heritage rehabilitation and strengthening and also sustainability issues. The organization of the paper is the following: firstly the Haussmann building complex is defined, secondly, the metallic and timber floors are described and the strengthening techniques are explained. Finally, some conclusions are indicated. a) Aerial view b) Front view Fig. 1. The Haussmann building complex 2- The Haussmann floors The building complex is constituted by two Haussmann buildings, built between 1830 and 1841. Malhesherbe building on the left and Madeleine building on the right in Fig. 1-a). Malhesherbe building as a gross floor area of 365 m2 and 7 stories and Madeleine building as a gross floor area 416 m2 and 6 stories. The ground floor of the two buildings has a commercial use and the basement floor is used as a storage and to the technical equipment. The other floors are used for office purposes and housing. Site observations allowed to conclude that the structure is highly composite and conceived essentially with local materials. The main Haussmann facades are made of dressed stone, excepted the two upper floors which are made with a timber frame solution. The facades located in the backside are made with a timber frame or steel frame solution. Fig. 2-a) shows Malhesherbe and Madeleine buildings facades viewed from Malhesherbe boulevard, this is a typical Haussmann facade and Fig. 2- b) shows an elevation along the building complex. a) Front facade b) Elevation Fig. 2. Malhesherbe and Madeleine building complex geometric characteristics of the structural floor elements was realized. Resulting in a step description of the floors strengthening technique used. We strongly believe this paper will allow to better understand the actual floor strengthening construction techniques which minimize the introduction of new elements, (Tuba Sari, 2017) (Akadiri P.O., 2012), allowing further studies related to numerical modelling, heritage rehabilitation and strengthening and also sustainability issues. The organization of the paper is the following: firstly the Haussmann building complex is defined, secondly, the metallic and timber floors are described and the strengthening techniques are explained. Finally, some conclusions are indicated. a) Aerial view b) Front view Fig. 1. The Haussmann building complex 2- The Haussmann floors The building complex is constituted by two Haussmann buildings, built between 1830 and 1841. Malhesherbe building on the left and Madeleine building on the right in Fig. 1-a). Malhesherbe building as a gross floor area of 365 m2 and 7 stories and Madeleine building as a gross floor area 416 m2 and 6 stories. The ground floor of the two buildings has a commercial use and the basement floor is used as a storage and to the technical equipment. The other floors are used for office purposes and housing. Site observations allowed to conclude that the structure is highly composite and conceived essentially with local materials. The main Haussmann facades are made of dressed stone, excepted the two upper floors which are made with a timber frame solution. The facades located in the backside are made with a timber frame or steel frame solution. Fig. 2-a) shows Malhesherbe and Madeleine buildings facades viewed from Malhesherbe boulevard, this is a typical Haussmann facade and Fig. 2- b) shows an elevation along the building complex. a) Front facade b) Elevation Fig. 2. Malhesherbe and Madeleine building complex The building complex is constituted by two Haussmann buildings, built between 1830 and 1841. Malhesherbe building on the left and Madeleine building on the right in Fig. 1-a). Malhesherbe building as a gross floor area of 365 m2 and 7 stories and Madeleine building as a gross floor area 416 m2 and 6 stories. The ground floor of the two buildings has a commercial use and the base- ment floor is used as a storage and to the technical equipment. The other floors are used for office purposes and housing. Site observations allowed to conclude that the structure is highly com- posite and conceived essentially with local materials. The main Haussmann facades are made of dressed stone, excepted the two upper floors which are made with a timber frame solution. The facades located in the backside are made with a timber frame or steel frame solution. Fig. 2-a) shows Malhesherbe and Madeleine buildings facades viewed from Malhesherbe boulevard, this is a typical Haussmann facade and Fig. 2-b) shows an elevation along the building complex. Fig. 2 Malhesherbe and Madeleine building complex a) Front facade b) Elevation geometric characteristics of the structural floor elements was realized. Resulting in a step description of the floors strengthening technique used. We strongly believe this paper will allow to better understand the actual floor strengthening construction techniques which minimize the introduction of new elements, (Tuba Sari, 2017) (Akadiri P.O., 2012), allowing further studies related to numerical modelling, heritage rehabilitation and strengthening and also sustainability issues. The organization of the paper is the following: firstly the Haussmann building complex is defined, secondly, the metallic and timber floors are described and the strengthening techniques are explained. Finally, some conclusions are indicated. a) Aerial view b) Front view Fig. 1. The Haussmann building complex 2- The Haussmann floors The building complex is constituted by two Haussmann buildings, built between 1830 and 1841. Malhesherbe building on the left and Madeleine building on the right in Fig. 1-a). Malhesherbe building as a gross floor area of 365 m2 and 7 stories and Madeleine building as a gross floor area 416 m2 and 6 stories. The ground floor of the two buildings has a commercial use and the basement floor is used as a storage and to the technical equipment. The other floors are used for office purposes and housing. Site observations allowed to conclude that the structure is highly composite and conceived essentially with local materials. The main Haussmann facades are made of dressed stone, excepted the two upper floors which are made with a timber frame solution. The facades located in the backside are made with a timber frame or steel frame solution. Fig. 2-a) shows Malhesherbe and Madeleine buildings facades viewed from Malhesherbe boulevard, this is a typical Haussmann facade and Fig. 2- b) shows an elevation along the building complex. a) Front facade b) Elevation Fig. 2. Malhesherbe and Madeleine building complex geometric characteristics of the structural floor elements was realized. Resulting in a step description of the floors strengthening technique used. We strongly believe this paper will allow to better understand the actual floor strengthening construction techniques which minimize the introduction of new elements, (Tuba Sari, 2017) (Akadiri P.O., 2012), allowing further studies related to numerical modelling, heritage rehabilitation and strengthening and also sustainability issues. The organization of the paper is the following: firstly the Haussmann building complex is defined, secondly, the metallic and timber floors are described and the strengthening techniques are explained. Finally, some conclusions are indicated. a) Aerial view b) Front view Fig. 1. The Haussmann building complex 2- The Haussmann floors The building complex is constituted by two Haussmann buildings, built between 1830 and 1841. Malhesherbe building on the left and Madeleine building on the right in Fig. 1-a). Malhesherbe building as a gross floor area of 365 m2 and 7 stories and Madeleine building as a gross floor area 416 m2 and 6 stories. The ground floor of the two buildings has a commercial use and the basement floor is used as a storage and to the technical equipment. The other floors are used for office purposes and housing. Site observations allowed to conclude that the structure is highly composite and conceived essentially with local materials. The main Haussmann facades are made of dressed stone, excepted the two upper floors which are made with a timber frame solution. The facades located in the backside are made with a timber frame or steel frame solution. Fig. 2-a) shows Malhesherbe and Madeleine buildings facades viewed from Malhesherbe boulevard, this is a typical Haussmann facade and Fig. 2- b) shows an elevation along the building complex. a) Front facade b) Elevation Fig. 2. Malhesherbe and Madeleine building complex Journal of Sustainable Architecture and Civil Engineering 2018/2/23 18 The interior walls are made with bricks or a timber structure filled with limestone. The basement walls located in the building complex perimeter are limestone rubble masonry, while the interior walls can be made with limestone rubble masonry or clay bricks. Foundation investigations re- vealed that the foundations of the existing walls are essentially realized extending downward the walls from 15 cm to 1 meter below the ground. Sometimes a concrete or limestone masonry strip footing or a limestone footing is placed beneath the walls. The floors structural system are of two types. The first type refers to floors made of a timber joist with floorboards attached to it and the second type is related to a floor system realized with a metallic joist and plaster interjoists. All the stories of Malhesherbe building are made with timber floors, while in Madeleine building and Fig. 3 Timber floors a) Laths and plaster under beams b) Laths and plaster bellow beams Fig. 4 Timber floors a) Timber floor view b) Timber floor detail The interior walls are made with bricks or a timber structure filled with limestone. The basement walls located in the building complex perimeter are limestone rubble masonry, while the interior walls can be made with limestone rubble masonry or clay bricks. Foundation investigations revealed that the foundations of the existing walls are essentially realized extending downward the walls from 15 cm to 1 meter below the ground. Sometimes a concrete or limestone masonry strip footing or a limestone footing is placed beneath the walls. The floors structural system are of two types. The first type refers to floors made of a timber joist with floorboards attached to it and the second type is related to a floor system realized with a metallic joist and plaster interjoists. All the stories of Malhesherbe building are made with timber floors, while in Madeleine building and starting in the third floor, IAO metallic profiles, the existing metallic profiles prior to the actual IPE/IPN profiles, are the solution considered for the floors. this distribution clearly indicates a technical evolution from timber floors to metallic floors. 2.1 Timber floors The investigations have shown that the timber floors do not have more the required resistance and stiffness to safely carry the loads. Several beams present large deformations or have extensive cracks. A weakening due to attacks by wood-eating insects and fungi is also evident. Furthermore, the floorboards are clearly deformed by the normal decay. These floors are made with resistant timber beams made of massif oak, below theme there is the floor ceiling made with laths and plaster attached and under the beams, Fig. 3-a), laths and a mortar support the floorboard revetment, as shown in Fig 3- b), (Cardoso R. and Pinto J., 2015). a) Laths and plaster under beams b) Laths and plaster bellow beams Fig. 3. Timber floors The technical survey performed on several timber floors, Fig. 4-a), allow identifying different typologies along the stories. More than sixteen type of floors were identified, varying the dimensions of the timber beams and their spacing, Fig. 4-b). The spacing (L) between beams varies 16 to 30 cm, the width (B) of the beams varies between 7 cm and 12 cm and can exceptionally reach 24 cm and finally, the beam height (H) varies from 15 cm to 26 cm. H B L a) Timber floor view b) Timber floor detail Fig. 4. Timber floors The interior walls are made with bricks or a timber structure filled with limestone. The basement walls located in the building complex perimeter are limestone rubble masonry, while the interior walls can be made with limestone rubble masonry or clay bricks. Foundation investigations revealed that the foundations of the existing walls are essentially realized extending downward the walls from 15 cm to 1 meter below the ground. Sometimes a concrete or limestone masonry strip footing or a limestone footing is placed beneath the walls. The floors structural system are of two types. The first type refers to floors made of a timber joist with floorboards attached to it and the second type is related to a floor system realized with a metallic joist and plaster interjoists. All the stories of Malhesherbe building are made with timber floors, while in Madeleine building and starting in the third floor, IAO metallic profiles, the existing metallic profiles prior to the actual IPE/IPN profiles, are the solution considered for the floors. this distribution clearly indicates a technical evolution from timber floors to metallic floors. 2.1 Timber floors The investigations have shown that the timber floors do not have more the required resistance and stiffness to safely carry the loads. Several beams present large deformations or have extensive cracks. A weakening due to attacks by wood-eating insects and fungi is also evident. Furthermore, the floorboards are clearly deformed by the normal decay. These floors are made with resistant timber beams made of massif oak, below theme there is the floor ceiling made with laths and plaster attached and under the beams, Fig. 3-a), laths and a mortar support the floorboard revetment, as shown in Fig 3- b), (Cardoso R. and Pinto J., 2015). a) Laths and plaster under beams b) Laths and plaster bellow beams Fig. 3. Timber floors The technical survey performed on several timber floors, Fig. 4-a), allow identifying different typologies along the stories. More than sixteen type of floors were identified, varying the dimensions of the timber beams and their spacing, Fig. 4-b). The spacing (L) between beams varies 16 to 30 cm, the width (B) of the beams varies between 7 cm and 12 cm and can exceptionally reach 24 cm and finally, the beam height (H) varies from 15 cm to 26 cm. H B L a) Timber floor view b) Timber floor detail Fig. 4. Timber floors The interior walls are made with bricks or a timber structure filled with limestone. The basement walls located in the building complex perimeter are limestone rubble masonry, while the interior walls can be made with limestone rubble masonry or clay bricks. Foundation investigations revealed that the foundations of the existing walls are essentially realized extending downward the walls from 15 cm to 1 meter below the ground. Sometimes a concrete or limestone masonry strip footing or a limestone footing is placed beneath the walls. The floors structural system are of two types. The first type refers to floors made of a timber joist with floorboards attached to it and the second type is related to a floor system realized with a metallic joist and plaster interjoists. All the stories of Malhesherbe building are made with timber floors, while in Madeleine building and starting in the third floor, IAO metallic profiles, the existing metallic profiles prior to the actual IPE/IPN profiles, are the solution considered for the floors. this distribution clearly indicates a technical evolution from timber floors to metallic floors. 2.1 Timber floors The investigations have shown that the timber floors do not have more the required resistance and stiffness to safely carry the loads. Several beams present large deformations or have extensive cracks. A weakening due to attacks by wood-eating insects and fungi is also evident. Furthermore, the floorboards are clearly deformed by the normal decay. These floors are made with resistant timber beams made of massif oak, below theme there is the floor ceiling made with laths and plaster attached and under the beams, Fig. 3-a), laths and a mortar support the floorboard revetment, as shown in Fig 3- b), (Cardoso R. and Pinto J., 2015). a) Laths and plaster under beams b) Laths and plaster bellow beams Fig. 3. Timber floors The technical survey performed on several timber floors, Fig. 4-a), allow identifying different typologies along the stories. More than sixteen type of floors were identified, varying the dimensions of the timber beams and their spacing, Fig. 4-b). The spacing (L) between beams varies 16 to 30 cm, the width (B) of the beams varies between 7 cm and 12 cm and can exceptionally reach 24 cm and finally, the beam height (H) varies from 15 cm to 26 cm. H B L a) Timber floor view b) Timber floor detail Fig. 4. Timber floors The interior walls are made with bricks or a timber structure filled with limestone. The basement walls located in the building complex perimeter are limestone rubble masonry, while the interior walls can be made with limestone rubble masonry or clay bricks. Foundation investigations revealed that the foundations of the existing walls are essentially realized extending downward the walls from 15 cm to 1 meter below the ground. Sometimes a concrete or limestone masonry strip footing or a limestone footing is placed beneath the walls. The floors structural system are of two types. The first type refers to floors made of a timber joist with floorboards attached to it and the second type is related to a floor system realized with a metallic joist and plaster interjoists. All the stories of Malhesherbe building are made with timber floors, while in Madeleine building and starting in the third floor, IAO metallic profiles, the existing metallic profiles prior to the actual IPE/IPN profiles, are the solution considered for the floors. this distribution clearly indicates a technical evolution from timber floors to metallic floors. 2.1 Timber floors The investigations have shown that the timber floors do not have more the required resistance and stiffness to safely carry the loads. Several beams present large deformations or have extensive cracks. A weakening due to attacks by wood-eating insects and fungi is also evident. Furthermore, the floorboards are clearly deformed by the normal decay. These floors are made with resistant timber beams made of massif oak, below theme there is the floor ceiling made with laths and plaster attached and under the beams, Fig. 3-a), laths and a mortar support the floorboard revetment, as shown in Fig 3- b), (Cardoso R. and Pinto J., 2015). a) Laths and plaster under beams b) Laths and plaster bellow beams Fig. 3. Timber floors The technical survey performed on several timber floors, Fig. 4-a), allow identifying different typologies along the stories. More than sixteen type of floors were identified, varying the dimensions of the timber beams and their spacing, Fig. 4-b). The spacing (L) between beams varies 16 to 30 cm, the width (B) of the beams varies between 7 cm and 12 cm and can exceptionally reach 24 cm and finally, the beam height (H) varies from 15 cm to 26 cm. H B L a) Timber floor view b) Timber floor detail Fig. 4. Timber floors starting in the third floor, IAO metallic profiles, the existing metallic profiles prior to the actual IPE/ IPN profiles, are the solution considered for the floors. this distribution clearly indicates a technical evolution from timber floors to metallic floors. Timber floors The investigations have shown that the timber floors do not have more the required resistance and stiffness to safely carry the loads. Several beams present large deformations or have extensive cracks. A weakening due to attacks by wood-eat- ing insects and fungi is also evident. Furthermore, the floorboards are clearly deformed by the nor- mal decay. These floors are made with resistant timber beams made of massif oak, below theme there is the floor ceiling made with laths and plas- ter attached and under the beams, Fig. 3-a), laths and a mortar support the floorboard revetment, as shown in Fig 3-b), (Cardoso R. and Pinto J., 2015). The technical survey performed on several timber floors, Fig. 4-a), allow identifying different typolo- gies along the stories. More than sixteen type of floors were identified, varying the dimensions of the timber beams and their spacing, Fig. 4-b). The spacing (L) between beams varies 16 to 30 cm, the width (B) of the beams varies between 7 cm and 12 cm and can exceptionally reach 24 cm and finally, the beam height (H) varies from 15 cm to 26 cm. Strengthening technique The rehabilitation works plan to this complex con- sider the rehabilitation and strengthening of sev- eral timber floors because they do not have the necessary load carrying capacity, but also because regarding the overall building stability they do not brace correctly the structure against possible hor- izontal movements of the facade, (Branco, 2006). The strengthening work consists in pouring a new concrete slab under the existing timber beams. In 19 Journal of Sustainable Architecture and Civil Engineering 2018/2/23 this operation, all the connected slab have 8 cm thickness. In order to realize this work, we must consider 6 steps. The initial state of the timber pavement is illustrated in Fig. 5 and represented by the existing timber beams and a lath and plaster layer. Fig. 5 Initial state 2.2 Strengthening technique The rehabilitation works plan to this complex consider the rehabilitation and strengthening of several timber floors because they do not have the necessary load carrying capacity, but also because regarding the overall building stability they do not brace correctly the structure against possible horizontal movements of the facade, (Branco, 2006). The strengthening work consists in pouring a new concrete slab under the existing timber beams. In this operation, all the connected slab have 8 cm thickness. In order to realize this work, we must consider 6 steps. The initial state of the timber pavement is illustrated in Fig. 5 and represented by the existing timber beams and a lath and plaster layer. Fig. 5. Initial state In the first step, the existing lath and plaster layer elements are eliminated, a shoring tower tour is necessary. This shoring tower has beams and a lost formwork, Fig. 6. Fig. 6. Existing timber pavement elimination In the second step, timber boards are put laterally on the timber beams which will be connected to the future concrete slab and cushioning timber elements are put on the timber beams which will be not connected, as illustrated in Fig. 7. Fig. 7. Timber boards In the third step, a lost formwork is put under the timber boards and on the cushioning timber elements to pour the concrete slab. Finally, the shoring tower is moved to another area and the previous operations are repeated, Fig. 8. 2.2 Strengthening technique The rehabilitation works plan to this complex consider the rehabilitation and strengthening of several timber floors because they do not have the necessary load carrying capacity, but also because regarding the overall building stability they do not brace correctly the structure against possible horizontal movements of the facade, (Branco, 2006). The strengthening work consists in pouring a new concrete slab under the existing timber beams. In this operation, all the connected slab have 8 cm thickness. In order to realize this work, we must consider 6 steps. The initial state of the timber pavement is illustrated in Fig. 5 and represented by the existing timber beams and a lath and plaster layer. Fig. 5. Initial state In the first step, the existing lath and plaster layer elements are eliminated, a shoring tower tour is necessary. This shoring tower has beams and a lost formwork, Fig. 6. Fig. 6. Existing timber pavement elimination In the second step, timber boards are put laterally on the timber beams which will be connected to the future concrete slab and cushioning timber elements are put on the timber beams which will be not connected, as illustrated in Fig. 7. Fig. 7. Timber boards In the third step, a lost formwork is put under the timber boards and on the cushioning timber elements to pour the concrete slab. Finally, the shoring tower is moved to another area and the previous operations are repeated, Fig. 8. 2.2 Strengthening technique The rehabilitation works plan to this complex consider the rehabilitation and strengthening of several timber floors because they do not have the necessary load carrying capacity, but also because regarding the overall building stability they do not brace correctly the structure against possible horizontal movements of the facade, (Branco, 2006). The strengthening work consists in pouring a new concrete slab under the existing timber beams. In this operation, all the connected slab have 8 cm thickness. In order to realize this work, we must consider 6 steps. The initial state of the timber pavement is illustrated in Fig. 5 and represented by the existing timber beams and a lath and plaster layer. Fig. 5. Initial state In the first step, the existing lath and plaster layer elements are eliminated, a shoring tower tour is necessary. This shoring tower has beams and a lost formwork, Fig. 6. Fig. 6. Existing timber pavement elimination In the second step, timber boards are put laterally on the timber beams which will be connected to the future concrete slab and cushioning timber elements are put on the timber beams which will be not connected, as illustrated in Fig. 7. Fig. 7. Timber boards In the third step, a lost formwork is put under the timber boards and on the cushioning timber elements to pour the concrete slab. Finally, the shoring tower is moved to another area and the previous operations are repeated, Fig. 8. Fig. 6 Existing timber pavement elimination Fig. 7 Timber boards In the first step, the existing lath and plaster layer elements are eliminated, a shoring tower tour is necessary. This shoring tower has beams and a lost formwork, Fig. 6. In the second step, timber boards are put laterally on the timber beams which will be connected to the future concrete slab and cushioning timber elements are put on the timber beams which will be not connected, as illustrated in Fig. 7. In the third step, a lost formwork is put under the timber boards and on the cushioning timber elements to pour the concrete slab. Finally, the shoring tower is moved to another area and the previous operations are repeated, Fig. 8. In the fourth step, connectors are put in place, their spacing and number are obtained after calcu- lations, Fig. 9. In the fifth step, the reinforcement corresponding to the concrete slab is put in place, Fig. 10. Each time the shoring tower is not used it must be validated by the design office. Journal of Sustainable Architecture and Civil Engineering 2018/2/23 20 Finally in the sixth step, after putting in place the shoring tower under the beams, following the studies performed by the design office, the slab is poured with a concrete pump, Fig. 11. Fig. 10 Reinforcement introdution Fig. 9 Connectors Fig. 8 Lost formwork Fig. 8. Lost formwork In the fourth step, connectors are put in place, their spacing and number are obtained after calculations, Fig. 9. Fig. 9. Connectors In the fifth step, the reinforcement corresponding to the concrete slab is put in place, Fig. 10. Each time the shoring tower is not used it must be validated by the design office. Fig. 10. Reinforcement introdution Finally in the sixth step, after putting in place the shoring tower under the beams, following the studies performed by the design office, the slab is poured with a concrete pump, Fig. 11. Fig. 11. Concrete slab connected Fig. 11. clearly shows that this technique allowed to maintain an important quantity of existing materials and therefore it can be classified as a sustainable strengthening technique. This will not have been the case if instead a complete 20-25 cm thickness traditional concrete slab should have been poured. Fig. 8. Lost formwork In the fourth step, connectors are put in place, their spacing and number are obtained after calculations, Fig. 9. Fig. 9. Connectors In the fifth step, the reinforcement corresponding to the concrete slab is put in place, Fig. 10. Each time the shoring tower is not used it must be validated by the design office. Fig. 10. Reinforcement introdution Finally in the sixth step, after putting in place the shoring tower under the beams, following the studies performed by the design office, the slab is poured with a concrete pump, Fig. 11. Fig. 11. Concrete slab connected Fig. 11. clearly shows that this technique allowed to maintain an important quantity of existing materials and therefore it can be classified as a sustainable strengthening technique. This will not have been the case if instead a complete 20-25 cm thickness traditional concrete slab should have been poured. Fig. 8. Lost formwork In the fourth step, connectors are put in place, their spacing and number are obtained after calculations, Fig. 9. Fig. 9. Connectors In the fifth step, the reinforcement corresponding to the concrete slab is put in place, Fig. 10. Each time the shoring tower is not used it must be validated by the design office. Fig. 10. Reinforcement introdution Finally in the sixth step, after putting in place the shoring tower under the beams, following the studies performed by the design office, the slab is poured with a concrete pump, Fig. 11. Fig. 11. Concrete slab connected Fig. 11. clearly shows that this technique allowed to maintain an important quantity of existing materials and therefore it can be classified as a sustainable strengthening technique. This will not have been the case if instead a complete 20-25 cm thickness traditional concrete slab should have been poured. Fig. 11 Concrete slab connected Fig. 8. Lost formwork In the fourth step, connectors are put in place, their spacing and number are obtained after calculations, Fig. 9. Fig. 9. Connectors In the fifth step, the reinforcement corresponding to the concrete slab is put in place, Fig. 10. Each time the shoring tower is not used it must be validated by the design office. Fig. 10. Reinforcement introdution Finally in the sixth step, after putting in place the shoring tower under the beams, following the studies performed by the design office, the slab is poured with a concrete pump, Fig. 11. Fig. 11. Concrete slab connected Fig. 11. clearly shows that this technique allowed to maintain an important quantity of existing materials and therefore it can be classified as a sustainable strengthening technique. This will not have been the case if instead a complete 20-25 cm thickness traditional concrete slab should have been poured. Fig. 11. clearly shows that this technique allowed to maintain an important quantity of existing materials and therefore it can be classified as a sustainable strengthening technique. This will not have been the case if instead a complete 20-25 cm thickness traditional concrete slab should have been poured. The metallic floors Some floors are made of metallic beams, in fact, starting on the 3rd floor of Madeleine building, the floors are realized with metal beams constituted of IAO cross-sections, Fig.12 a). Between 21 Journal of Sustainable Architecture and Civil Engineering 2018/2/23 Fig. 12 Metallic IAO floors a ) Metallic floor b) Metallic floor detail 2.3 The metallic floors Some floors are made of metallic beams, in fact, starting on the 3rd floor of Madeleine building, the floors are realized with metal beams constituted of IAO cross-sections, Fig.12 a). Between those beams, plaster interjoist elements are set, Fig. 12-b). The investigation on metallic IAO profiles indicated high deflections and plaster cover deterioration. Furthermore, the design calculations indicate also that those floors do not have the necessary resistance to withstand the new loads rising from the new regulations (EN 1991-1-1, 2002) and due to the new service conditions, corresponding to a hotel. a ) Metallic floor b) Metallic floor detail Fig. 12. Metallic IAO floors Investigation on the metallic IAO profiles allowed to identify three types of metallic floors, depending one the IAO dimensions, the results are indicated in Table 1 and relative to Madeleine building. Table 1. IAO cross-section dimensions Cross-section dimensions (cm) Floor Designation Flanges width Height Spacing 4th D1 6 16 63 5th D2 6 16 60 D3 6 16 58 The flanges width of the IAO profiles is equal to 6 cm, the height to 16 cm and the spacing between beams varies from 58 to 63 cm. Beyond that, tensile tests ordered to Veritas office and realized in IAO cross-section beams indicated a yield strength varying from 258 MPa and 283 MPa, and a Young modulus varying from 179 to 187 GPa. These results indicate that the metallic profiles still present good mechanical characteristics, in fact, the actual minimum tensile yield strength for metallic profiles is 360 MPa and the Young modulus is 200 GPa, (EN 1993-1-1, 2005). The protection given by the existing plaster infill around the metallic profiles certainly justifies those values (Cardoso et al., 2016). 2.4 Strengthening techniques The strengthening technique for the existing metallic floors consists in maintaining the IAO profiles and creating a new concrete slab. Three solutions can be considered, in the first a concrete slab is connected to the metallic IAO profiles, the existing plaster interjoist is kept in place, Fig. 13 illustrates this solution. The thickness of the connected concrete slab can vary between 8 and 12 cm. 2.3 The metallic floors Some floors are made of metallic beams, in fact, starting on the 3rd floor of Madeleine building, the floors are realized with metal beams constituted of IAO cross-sections, Fig.12 a). Between those beams, plaster interjoist elements are set, Fig. 12-b). The investigation on metallic IAO profiles indicated high deflections and plaster cover deterioration. Furthermore, the design calculations indicate also that those floors do not have the necessary resistance to withstand the new loads rising from the new regulations (EN 1991-1-1, 2002) and due to the new service conditions, corresponding to a hotel. a ) Metallic floor b) Metallic floor detail Fig. 12. Metallic IAO floors Investigation on the metallic IAO profiles allowed to identify three types of metallic floors, depending one the IAO dimensions, the results are indicated in Table 1 and relative to Madeleine building. Table 1. IAO cross-section dimensions Cross-section dimensions (cm) Floor Designation Flanges width Height Spacing 4th D1 6 16 63 5th D2 6 16 60 D3 6 16 58 The flanges width of the IAO profiles is equal to 6 cm, the height to 16 cm and the spacing between beams varies from 58 to 63 cm. Beyond that, tensile tests ordered to Veritas office and realized in IAO cross-section beams indicated a yield strength varying from 258 MPa and 283 MPa, and a Young modulus varying from 179 to 187 GPa. These results indicate that the metallic profiles still present good mechanical characteristics, in fact, the actual minimum tensile yield strength for metallic profiles is 360 MPa and the Young modulus is 200 GPa, (EN 1993-1-1, 2005). The protection given by the existing plaster infill around the metallic profiles certainly justifies those values (Cardoso et al., 2016). 2.4 Strengthening techniques The strengthening technique for the existing metallic floors consists in maintaining the IAO profiles and creating a new concrete slab. Three solutions can be considered, in the first a concrete slab is connected to the metallic IAO profiles, the existing plaster interjoist is kept in place, Fig. 13 illustrates this solution. The thickness of the connected concrete slab can vary between 8 and 12 cm. those beams, plaster interjoist elements are set, Fig. 12-b). The investigation on metallic IAO pro- files indicated high deflections and plaster cover deterioration. Fur- thermore, the design calculations indicate also that those floors do not have the necessary resis- tance to withstand the new loads rising from the new regulations (EN 1991-1-1, 2002) and due to the new service conditions, corre- sponding to a hotel. Investigation on the metallic IAO profiles allowed to identify three types of metallic floors, depending one the IAO dimensions, the results are indicated in Table 1 and relative to Madeleine building. The flanges width of the IAO pro- files is equal to 6 cm, the height to 16 cm and the spacing between beams varies from 58 to 63 cm. Beyond that, tensile tests ordered to Veritas office and realized in IAO cross-section beams indicat- ed a yield strength varying from 258 MPa and 283 MPa, and a Young modulus varying from 179 to 187 GPa. These results indicate that the metallic profiles still present good mechanical characteristics, in fact, the actual minimum tensile yield strength for metallic profiles is 360 MPa and the Young modulus is 200 GPa, (EN 1993-1-1, 2005). The pro- tection given by the existing plaster infill around the metallic profiles certainly justifies those values (Cardoso et al., 2016). Strengthening techniques The strengthening technique for the existing metallic floors consists in maintaining the IAO profiles and Table 1 IAO cross-section dimensions Cross-section dimensions (cm) Floor Designation Flanges width Height Spacing 4th D1 6 16 63 5th D2 6 16 60 D3 6 16 58 Fig. 13. Connected concrete slab The second solution, consider the elimination of the plaster interjoist, only the metallic IAO profiles are maintained in place. A traditional reinforced concrete slab is put in place. In this solution, the resistance of the floor is the sum of a concrete slab plus the resistance obtained from the IAO profiles, Fig.14. Fig. 14. Full concrete slab Finally, a third solution, intermediate between the first and the second solution can be considered. The plaster interjoist is partially eliminated and a concrete slab is poured. In terms of resistance, we can also consider that the resistance of this floor is given by the sum of the IAO resistance and the reinforced concrete slab, Fig. 15. Fig. 15. Concrete slab In the followings, we introduce the several steps regarding the strengthening of a metallic floor with a connected concrete slab, corresponding to the first solution, Fig.13. In the first step, the metallic floor is cleaned and only the IAO profiles and the plaster interjoist are maintained, this corresponds to the initial state, Fig. 16. Fig. 16. Initial state Secondly, a lightweight concrete is added in the volume between the interjoist and the top of the IAO profile, Fig. 17. creating a new concrete slab. Three solutions can be considered, in the first a concrete slab is con- nected to the metallic IAO profiles, the existing plaster interjoist is kept in place, Fig. 13 illustrates this solution. The thickness of the connected concrete slab can vary between 8 and 12 cm. The second solution, consider the elimination of the plaster interjoist, only the metallic IAO profiles Fig. 13 Connected concrete slab Journal of Sustainable Architecture and Civil Engineering 2018/2/23 22 are maintained in place. A traditional reinforced con- crete slab is put in place. In this solution, the resistance of the floor is the sum of a concrete slab plus the re- sistance obtained from the IAO profiles, Fig.14. Finally, a third solution, intermediate between the first and the second solu- tion can be considered. The plaster interjoist is partially eliminated and a concrete slab is poured. In terms of resistance, we can also consider that the resis- tance of this floor is given Fig. 14 Full concrete slab Fig. 15 Concrete slab Fig. 16 Initial state Fig. 17 Lightweight concrete Fig. 18 Steel connectors Fig. 13. Connected concrete slab The second solution, consider the elimination of the plaster interjoist, only the metallic IAO profiles are maintained in place. A traditional reinforced concrete slab is put in place. In this solution, the resistance of the floor is the sum of a concrete slab plus the resistance obtained from the IAO profiles, Fig.14. Fig. 14. Full concrete slab Finally, a third solution, intermediate between the first and the second solution can be considered. The plaster interjoist is partially eliminated and a concrete slab is poured. In terms of resistance, we can also consider that the resistance of this floor is given by the sum of the IAO resistance and the reinforced concrete slab, Fig. 15. Fig. 15. Concrete slab In the followings, we introduce the several steps regarding the strengthening of a metallic floor with a connected concrete slab, corresponding to the first solution, Fig.13. In the first step, the metallic floor is cleaned and only the IAO profiles and the plaster interjoist are maintained, this corresponds to the initial state, Fig. 16. Fig. 16. Initial state Secondly, a lightweight concrete is added in the volume between the interjoist and the top of the IAO profile, Fig. 17. Fig. 13. Connected concrete slab The second solution, consider the elimination of the plaster interjoist, only the metallic IAO profiles are maintained in place. A traditional reinforced concrete slab is put in place. In this solution, the resistance of the floor is the sum of a concrete slab plus the resistance obtained from the IAO profiles, Fig.14. Fig. 14. Full concrete slab Finally, a third solution, intermediate between the first and the second solution can be considered. The plaster interjoist is partially eliminated and a concrete slab is poured. In terms of resistance, we can also consider that the resistance of this floor is given by the sum of the IAO resistance and the reinforced concrete slab, Fig. 15. Fig. 15. Concrete slab In the followings, we introduce the several steps regarding the strengthening of a metallic floor with a connected concrete slab, corresponding to the first solution, Fig.13. In the first step, the metallic floor is cleaned and only the IAO profiles and the plaster interjoist are maintained, this corresponds to the initial state, Fig. 16. Fig. 16. Initial state Secondly, a lightweight concrete is added in the volume between the interjoist and the top of the IAO profile, Fig. 17. Fig. 13. Connected concrete slab The second solution, consider the elimination of the plaster interjoist, only the metallic IAO profiles are maintained in place. A traditional reinforced concrete slab is put in place. In this solution, the resistance of the floor is the sum of a concrete slab plus the resistance obtained from the IAO profiles, Fig.14. Fig. 14. Full concrete slab Finally, a third solution, intermediate between the first and the second solution can be considered. The plaster interjoist is partially eliminated and a concrete slab is poured. In terms of resistance, we can also consider that the resistance of this floor is given by the sum of the IAO resistance and the reinforced concrete slab, Fig. 15. Fig. 15. Concrete slab In the followings, we introduce the several steps regarding the strengthening of a metallic floor with a connected concrete slab, corresponding to the first solution, Fig.13. In the first step, the metallic floor is cleaned and only the IAO profiles and the plaster interjoist are maintained, this corresponds to the initial state, Fig. 16. Fig. 16. Initial state Secondly, a lightweight concrete is added in the volume between the interjoist and the top of the IAO profile, Fig. 17. Fig. 13. Connected concrete slab The second solution, consider the elimination of the plaster interjoist, only the metallic IAO profiles are maintained in place. A traditional reinforced concrete slab is put in place. In this solution, the resistance of the floor is the sum of a concrete slab plus the resistance obtained from the IAO profiles, Fig.14. Fig. 14. Full concrete slab Finally, a third solution, intermediate between the first and the second solution can be considered. The plaster interjoist is partially eliminated and a concrete slab is poured. In terms of resistance, we can also consider that the resistance of this floor is given by the sum of the IAO resistance and the reinforced concrete slab, Fig. 15. Fig. 15. Concrete slab In the followings, we introduce the several steps regarding the strengthening of a metallic floor with a connected concrete slab, corresponding to the first solution, Fig.13. In the first step, the metallic floor is cleaned and only the IAO profiles and the plaster interjoist are maintained, this corresponds to the initial state, Fig. 16. Fig. 16. Initial state Secondly, a lightweight concrete is added in the volume between the interjoist and the top of the IAO profile, Fig. 17. Fig. 17. Lightweight concrete Thirdly, Hilti X-HVB steel connectors are put in the top of the IAO profiles, the spacing and number of connectors being calculated by the design office, Fig. 18. Fig. 18. Steel connectors Fourthly, since the IAO profiles do not have necessarily the same height, polystyrene boards are put in place in order to create a perfectly horizontal surface, Fig. 19. Fig. 19. Polystyrene boards Fifthly, the slab reinforcement is added, Fig. 20. Fig. 20. Slab reinforcement Finally, the concrete slab is poured, Fig. 21. Fig. 21. Concrete slab It should be noted that the connectors used are 50 mm, 80 mm, 125 mm or 140 mm height, depending on the IAO profiles height. Conclusions The planning and design of strengthening techniques play a very important role in the global sustainable development. The demand for strengthening has increased in the last years as renewals and refurbishment of old buildings have gained popularity, mainly in the European oldest cities. This type of work requires skilled labor, not only constructors but also in the planning stage, since there is not a universal solution applicable to all cases. The rehabilitation and strengthening work realized in the floors intended among others to eliminate their pathologies and increase their resistance and stiffness. The strengthening technique described for the floors is essentially based on pouring a concrete slab connected to the timber beams or to the IAO by the sum of the IAO resistance and the reinforced concrete slab, Fig. 15. In the followings, we introduce the several steps regarding the strengthening of a metallic floor with a connected concrete slab, corresponding to the first solution, Fig.13. In the first step, the metallic floor is cleaned and only the IAO profiles and the plaster interjoist are maintained, this corresponds to the initial state, Fig. 16. Secondly, a lightweight concrete is added in the volume between the interjoist and the top of the IAO profile, Fig. 17. Thirdly, Hilti X-HVB steel connectors are put in the top of the IAO profiles, the spacing and number of connectors being calculated by the design office, Fig. 18. 23 Journal of Sustainable Architecture and Civil Engineering 2018/2/23 Fig. 19 Polystyrene boards Fig. 20 Slab reinforcement Fig. 21 Concrete slab Fig. 17. Lightweight concrete Thirdly, Hilti X-HVB steel connectors are put in the top of the IAO profiles, the spacing and number of connectors being calculated by the design office, Fig. 18. Fig. 18. Steel connectors Fourthly, since the IAO profiles do not have necessarily the same height, polystyrene boards are put in place in order to create a perfectly horizontal surface, Fig. 19. Fig. 19. Polystyrene boards Fifthly, the slab reinforcement is added, Fig. 20. Fig. 20. Slab reinforcement Finally, the concrete slab is poured, Fig. 21. Fig. 21. Concrete slab It should be noted that the connectors used are 50 mm, 80 mm, 125 mm or 140 mm height, depending on the IAO profiles height. Conclusions The planning and design of strengthening techniques play a very important role in the global sustainable development. The demand for strengthening has increased in the last years as renewals and refurbishment of old buildings have gained popularity, mainly in the European oldest cities. This type of work requires skilled labor, not only constructors but also in the planning stage, since there is not a universal solution applicable to all cases. The rehabilitation and strengthening work realized in the floors intended among others to eliminate their pathologies and increase their resistance and stiffness. The strengthening technique described for the floors is essentially based on pouring a concrete slab connected to the timber beams or to the IAO Fourthly, since the IAO profiles do not have necessarily the same height, polystyrene boards are put in place in order to create a perfectly horizontal surface, Fig. 19. Fifthly, the slab reinforcement is added, Fig. 20. Finally, the concrete slab is poured, Fig. 21. It should be noted that the connectors used are 50 mm, 80 mm, 125 mm or 140 mm height, de- pending on the IAO profiles height. Fig. 17. Lightweight concrete Thirdly, Hilti X-HVB steel connectors are put in the top of the IAO profiles, the spacing and number of connectors being calculated by the design office, Fig. 18. Fig. 18. Steel connectors Fourthly, since the IAO profiles do not have necessarily the same height, polystyrene boards are put in place in order to create a perfectly horizontal surface, Fig. 19. Fig. 19. Polystyrene boards Fifthly, the slab reinforcement is added, Fig. 20. Fig. 20. Slab reinforcement Finally, the concrete slab is poured, Fig. 21. Fig. 21. Concrete slab It should be noted that the connectors used are 50 mm, 80 mm, 125 mm or 140 mm height, depending on the IAO profiles height. Conclusions The planning and design of strengthening techniques play a very important role in the global sustainable development. The demand for strengthening has increased in the last years as renewals and refurbishment of old buildings have gained popularity, mainly in the European oldest cities. This type of work requires skilled labor, not only constructors but also in the planning stage, since there is not a universal solution applicable to all cases. The rehabilitation and strengthening work realized in the floors intended among others to eliminate their pathologies and increase their resistance and stiffness. The strengthening technique described for the floors is essentially based on pouring a concrete slab connected to the timber beams or to the IAO Fig. 17. Lightweight concrete Thirdly, Hilti X-HVB steel connectors are put in the top of the IAO profiles, the spacing and number of connectors being calculated by the design office, Fig. 18. Fig. 18. Steel connectors Fourthly, since the IAO profiles do not have necessarily the same height, polystyrene boards are put in place in order to create a perfectly horizontal surface, Fig. 19. Fig. 19. Polystyrene boards Fifthly, the slab reinforcement is added, Fig. 20. Fig. 20. Slab reinforcement Finally, the concrete slab is poured, Fig. 21. Fig. 21. Concrete slab It should be noted that the connectors used are 50 mm, 80 mm, 125 mm or 140 mm height, depending on the IAO profiles height. Conclusions The planning and design of strengthening techniques play a very important role in the global sustainable development. The demand for strengthening has increased in the last years as renewals and refurbishment of old buildings have gained popularity, mainly in the European oldest cities. This type of work requires skilled labor, not only constructors but also in the planning stage, since there is not a universal solution applicable to all cases. The rehabilitation and strengthening work realized in the floors intended among others to eliminate their pathologies and increase their resistance and stiffness. The strengthening technique described for the floors is essentially based on pouring a concrete slab connected to the timber beams or to the IAO The planning and design of strengthening techniques play a very important role in the global sus- tainable development. The demand for strengthening has increased in the last years as renewals and refurbishment of old buildings have gained popularity, mainly in the European oldest cities. This type of work requires skilled labor, not only constructors but also in the planning stage, since there is not a universal solution applicable to all cases. The rehabilitation and strengthening work realized in the floors intended among others to eliminate their pathologies and increase their resistance and stiffness. The strengthening technique described for the floors is essentially based on pouring a concrete slab connected to the timber beams or to the IAO profiles. This strengthening technique retains a great amount of the original structure and mini- mizes the intervention and the introduction of new elements which lead to a cost-effective solution. It can be cataloged as a sustainable strengthening technique, ensuring at the same time to fulfill the actual requirements in terms of structural integrity, fire safety, thermal and soundproof insulation. Acknowledgement The author would like to acknowledge Julien Dequeker, site engineer and Paulo Oliveira site man- ager, both from Vinci construction, France, for their technical support. Conclusions ReferencesAkadiri P.O., Chinyio E.A., Olomalaiye P.O. Design of sustainable buildings: A conceptual framework for implementing sustainability in the building sector, Buildings, 2012, 2(1):126-152. https://doi. org/10.3390/buildings2020126 Branco J., Cruz P., Piazza M. and Varum H. Streng- thening techniques of Portuguese traditional tim- ber connections, Structural Analysis of Historical Constructions, P.B. Lourenço, P. Roca, C. Modena, S. Agrawal (Eds.), New Delhi, 2006. https://doi.org/10.3390/buildings2020126 https://doi.org/10.3390/buildings2020126 Journal of Sustainable Architecture and Civil Engineering 2018/2/23 24 Cardoso R., Pinto J. Tabique walls composite earth based material characterization in the Alto Douro Wine Region, Portugal. Constructii Journal of Civil Engineering Research, 2015, 16(2): 03 - 11. Cardoso R., Pinto J., Paiva A. Lanzinha J.C. Tabique walls typologies and building details in the Alto Do- uro Wine Region. Journal WSEAS Transactions on Environment and Development, 2015, Volume 11, Art.11, pp.95-107. Cardoso R., Pinto J., Pinto J., Lanzinha J.C. Cha- racterization of tabique wall nails of the Alto Douro Wine Region, Open Engineering, 2016, 6(1):446-454. Cardoso R., Pinto J., Paiva A., Lanzinha J.C. Earth-ba- sed material field tests characterization in the Alto Douro Wine Region. Open Engineering, 2017,6(1):435- 443. https://doi.org/10.1515/eng-2017-0048 Catarig Al., Kopenetz L., Structural problems of scafolds used in rehabilitation works of historical buildings, Acta Tech. Napocensis: Civil Eng. & Arch., 2007, Vol. 50, 57-67. EN 1991-1-1. Eurocode 1: Action on structures - Part 1-1: General actions – Densities, Self-weight, imposed loads for buildings, CEN Brussels, 2002. EN 1993-1-1 Eurocode 3: Design of stell structures- Part 1-1: General rules and rules for buildings Ru- les, CEN Brussels, 2005. Froidevaux Y. Techniques de l’architecture ancien- ne: construction et restauration [Ancient architec- ture technique: construction and restoration]. ISBN 2-87009-774-3. Pierre Mardaga Editeur, 1986. Jomber C.A. Architecture moderne, ou l’art de bien bâtir pour toutes sortes de personnes [Moderne Architecture or the good construction art for all ty- pes of persons], Tome premier de la construction, Librairie du Génie et de l´Artillerie , rue Dauphine Notre-Dame, Paris, 1764. Jordan D.P. Paris Haussmann and after, Jounal of urban history, 2015, 41(3): 541-549. Lepoutre D. Histoire d‘un immeuble haussmannien: Catégories d‘habitants et rapports d‘habitation en milieu bourgeois [History of a Haussmann building], Revue française de sociologie, 2010, 51(2):321-358. https://doi.org/10.3917/rfs.512.0321 Tuba Sari. Review on High-Rise Housing Projects in Istanbul: Toward a Sustainable Architecture. Jo- urnal of Sustainable Architecture and Civil Engine- ering, 2017, 18(1): 39-49. https://doi.org/10.5755/ j01.sace.18.1.16598 About the Author RUI CARDOSO Ph.D fellow researcher Civil Engineering and Architecture Department, Beira Interior University Main research area Sustainable construction techniques Address Civil Engineering and Architecture Department, Beira Interior University, 6201-001 Covilhã, Portugal Tel. 0033 (0)6 27 85 82 48 E-mail: jcardoso@ubi.pt https://doi.org/10.1515/eng-2017-0048 https://doi.org/10.3917/rfs.512.0321 https://doi.org/10.5755/j01.sace.18.1.16598 https://doi.org/10.5755/j01.sace.18.1.16598