1870 – 1920
Residential building construction (187o–192o)
The first great building boom took place in the era of industrialisation: mass housing construction on the outskirts of cities, which had frequently been left unchanged since the Middle Ages. No consideration was given to the topography and little attention was paid to the needs of the tenants. The beautiful large rooms were, in the best case, the living space for an entire family of four. To set limits to the worst out growths of profit maximisation, building regulations stipulated minimum room heights and prohibited basement apartments, for example. Today, these districts are highly sought-after and they will remain so. That they are now located within the city, in wide streets often lined with trees in a dense urban setting, makes them attractive. The building topology chosen was in line with the interests of the investors at that time. The expensive homes were fitted out with a richly adorned front, a spacious stairwell and oriels or balconies. The windows are generously sized. This contrasts with the rear houses, which were set back from the street and featured unplastered brick facades, narrow stairwells and rooms that were badly lit via courtyards and allowed access only on one side. The advantages and disadvantages of this system can only be balanced out by combining the apartments to make larger homes. In the front houses, it is always the longitudinal walls, two outer ones and one in the middle, that bear the load. The rear houses are the same but often have only two load-bearing walls. Because rigidity is achieved by means of the fire walls and the ceilings (anchored with tie rods to the outer walls), most inner walls have no structural function whatsoever. The large undifferentiated rooms were appropriate to the use which they were put to at the time. Combined with the non-load-bearing inner walls, they are the big advantage of apartments from this epoch today. From a typological point of view, almost any use is conceivable: a large apartment for a family but also for a well-off single person, a doctor’s surgery, the office of a freelance worker or combination of all the apartments to form a prestigious head office for a company. The high ceilings and the elegantly designed front houses result in living spaces that are often far superior to those of a new building. However, there are two weaknesses resulting from the physics of the buildings: the poor sound insulation and fire protection provided by the ceilings between floors. The wooden ceilings were made up to six metres wide and the floorboards were nailed directly onto them. In order to improve protection against air-borne noise and fire, mixed clay and straw or similar heavy building materials were placed on the inserted subfloors. The ceilings were covered with plaster applied to a plaster base. The filling materials mentioned were the best solution at the time and they do not, of course, meet present day standards. This becomes a problem when the apartments are rented out for high-quality lettings and especially when the use changes. In the latter case, they lose their protected status and the architect is tied to today’s building regulations. One of the few solutions is to replace the filling material with sound insulating materials and to add suspended fire ceilings and wash floors. The disadvantage this brings, however, is fairly substantial: floorboards and stucco ceilings are lost, window breast heights after renovation are problematic, as is access from the stairwell and many more formal details. Architects from this epoch used four basic materials: bricks, wood, lime and iron. Apart from the problem of dry rot, there is no need to worry about harmful substances in unrenovated residential buildings: the houses from that time are ‘bio’ through and through. Because the outer walls alone bear the load, they are correspondingly thick and solid on the lower floors. On the top floor, they are at least 25 cm thick and, every second floor downwards, they become 13 cm thicker. Their ability to store heat is very good, with the exception of the attic walls. Together with the solid middle wall and the large amount of space, apartments from this epoch have a very well balanced indoor climate. The thermal insulation, however, is inadequate, and renovation is not completely without its problems. If insulation is applied to the inside of the outer walls so as not to cover the stucco facade, the advantages of heat storage are lost. The thermal bridges, in contrast, can be ignored due to the wooden ceilings. What is more of a problem is the requirement that, after renovation, the new windows be air-tight and water-tight. Inadequate ventilation of the ends of the wooden beams in the outer walls can lead to rotting of the previously undamaged sections and thus to structural hazards.