About 70 “WOODCUBEs” could be produced and constructed using the same amount of carbon emissions as those produced by the construction and use of a conventional building over 50 years.
Carbon balance: due to the measures mentioned above, the proportion of timber used was much greater than originally planned, with the result that the amount of embodied (grey) energy, i.e. that used to construct the building, was greatly reduced. This had an impact on the carbon balance of the building.
The wood façade was originally to have been rear-ventilated and built with horizontal fire-protective sheets. The project was ultimately implemented with a wood façade containing separate air pockets. The coffer arrangement of the substructure meant that each coffer formed a “fire cell”, providing the necessary gaps. This mean that the horizontal metal sheets were no longer required.
The wood was originally to have been made visible through a transparent fire protection layer. This was revised so that additional untreated wood layers would act as sacrificial layers, part of the walls’ fire protection system.
Heat insulation was to be provided by conventional insulation in the load-bearing solid timber layer. This was revised so that the insulation would be provided by additional solid timber and wood fibreboard insulation.
The main changes in the planning phase were:
• Originally, only the structurally necessary parts of the walls were to be constructed with glued solid timber. This was revised so that the whole wall element would be built of glueless solid timber.
As a result of the changes made, the construction of the “WOODCUBE” used about 70 times less energy than the creation of a conventional building. The originally calculated costs had to be adjusted due to these changes. It was therefore agreed with the IBA that the concept would run under the banner of “Smart Materials” rather than “Smart Price”.
the choice of building materials was changed, with the agreement of the IBA, for reasons of sustainability and long-term affordability. Adaptations were made to details relating to the choice of timber construction system, building services, certification for the materials used, and aspects such as ventilation.
DeepGreen developed their solid wood elements in conjunction with various universities and specialists, and came up with a building system that could be replicated elsewhere.
While the project complied with the concept agreed with the IBA and all seven of the “IBA Excellence” criteria,
The Stuttgart-based firm architekturagentur was commissioned to implement DeepGreen’s ideas in planning and technical terms. The company Holz100 was brought in on the manufacturing side, as it had already carried out a number of innovative solid timber projects, particularly in Austria.
Encapsulation was completely avoided for the walls and ceilings (originally only the undersides of the ceilings were to have remained visible). Cooperation between DeepGreen, IfuH, and the rest of the competition team broke down over these decisions.
DeepGreen now took the decisive step of developing the project concept and sought to construct a building that made use of very few different materials, while remaining as free of toxic substances as possible and ensuring that the building components could be re-used.
For this reason, DeepGreen decided to use wood wherever possible. This meant that the original construction concept of additional insulated and glued cross-laminated timber walls had to be revised.
The project was to serve as a model of solid timber construction. It was required to meet the highest noise protection and fire safety requirements, without using conventional encapsulation or compensatory fire protection measures.
DeepGreen put the emphasis on long-term stability, as far as possible, and maximum environmental friendliness. The aim was a largely chemicalfree, single-material timber construction, with simple manufacturing and maintenance processes.
DeepGreen therefore took over all shares in the company and revised the project from scratch with the aim of fulfilling the development goals of the IBA, such as creating a sustainable model building that responded to climate change etc. as fully as possible.
Sound risks could not be eliminated. Fire safety requirements made the project more expensive and would have destabilising effects on the structure.
The construction partners could provide neither guarantees nor cost certainty.
Change from “Smart Price” to “Smart Material” Classification In the first stage it was, however, ascertained that various concepts from the competition submission would not be feasible in construction terms or within the economic constraints of the project. The 2.5 meter freely overhanging balconies, for example, could not pass a statics test.
...under the auspices of the project company WOODCUBE Hamburg GmbH, as investors in the project. Together with the IfuH, the project and the work that had gone into planning it moved from the competition stage to implementation.
For instance, consideration was given to having a mezzanine floor instead of the large communal roof terrace put forward by the joint building venture. In October 2010 DeepGreen Development GmbH entered into partnership with the P&P AG construction company, ...
However, both building contractors and developers voiced concerns about the timber construction in relation to noise protection, fire safety, and the intrinsic value of the material. In the course of these discussions, the planning was revised in various respects.
Constructed for a joint building venture, the project was not associated with a group of developers. As with many other smart material projects, the IBA Hamburg GmbH took on the task of approaching investors about the “WOODCUBE”.
The striking architectural concept and emphasis on the use of largely prefabricated timber as a building material qualified the “WOODCUBE” as a “Smart Price House” in the eyes of the jury. The low-tech charm of the project convinced the Büro Institut für urbanen Holzbau (IfuH) that it merited this distinction, along with the major achievements of making the building Passive House standard, while ensuring flexibility in the layout design and low costs.
The free layouts around a central access core formed part of the initial design. By implementing the building in timber and mixed construction, with an energy standard 30 per cent below the level stipulated in the energy conservation regulations (EnEV), the “WOODCUBE” was to serve as a model design in the “Smart Price Houses” category.
Competition In the first part of the two-stage “Smart Price Houses” competition, launched in late 2009, a planning team of architects and home technology experts developed a concept envisaging the “WOODCUBE” as a cost-effective, four-storey residential building designed especially for joint building ventures, based on glueless cross-laminated timber construction.