Living Box – Prefabricated modular wood-house system - Part IV - KEP energy Magazine - KEP energy

Living Box – Prefabricated modular wood-house system

English translation from a paper published in 'Bollettino degli Ingegneri n. 6/2016 pp. 3-18'

Architectonical and technological design of the Living Box

The design concept has been implemented in a system composed from two cell typologies: an “A-type” cell, having variable planimetric configuration and structurally beared from the “B-type” ones; a “B-type” cell, having fixed planimetric configuration and structurally bearing the “A-type” ones. The bathroom, the plants and the complementary services are inserted into this last cell type. Each “A-type” cell is flanked by two “B-type” cell.

The sizing criteria have been derived from the reference models detected during the preliminary analysis, checking the minimal geometric requirements for households, as the floors area, the rooms height and the aerial-illumination ratio (the daylight factor assessment, also a relevant topic, was not possible because at the design stage are unknow the Living Box geographic location and the possible external shading elements).

A square area having 1,5 m side length has been defined as basic geometric module. The “B-type” cells, serving the “A-type” ones, have net internal height equal to 2,40 m and fixed area surface equal to 1 x 2 modules, that is 1,5 x 3,0 m. The “A-type” cells, served from the “B-type” ones, have net internal height equal to 2,70 m and variable area surface ranging from 2x4 modules to 4x4 modules, that is from 3,0 x 6,0 m to 6,0 x 6,0 m.

The size variability of the “A-type” cell allows to obtain three different living unit configurations, respectively having 18, 28 and 36 m2 net indoor area, beyond the adjacent “B-type” cells areas. A net indoor area equal to 18 m2 is the reference standard size for the temporary housing systems.

A standard utilization pattern has been analysed for each configuration, as one-room dwelling, and also a series of alternatives utilization patterns have been analysed, as multi-rooms dwelling, composed from some living units horizontally and/or vertically combined among them. In this way it is possible configure modulable flats, in compliance with the single-room, two-rooms, three-rooms, etc. typologies. Moreover, the combination among a series of living units, through the insertion of interlinking staircases, allows to obtain multi-flats block buildings, in compliance with the terraced house, linear house, gallery house, etc. typologies.

Materials features. From the preliminary analysis emerged that the prefabricated building industry is currently based on two reference materials sets: multilayer panels having steel framed bearing structure and multilayer panels having timber-plated and/or timber-framed bearing structure. Both these sets are suitable for the Living Box project. Anyway, the project has been developed using the wood as main building material, because it represents an optimal convergence between structural performance and energy performance.

Prefabrication features. The Living-Box is given by two different prefabrication modalities: the “A-type” cells are afferent to the surfaces modality, more flexible, whilst the “B-type” cells are afferent to the volumes modality, less flexible. The choice is due respectively to the high level of compactness and functional seriality that characterizes the “B-type” cells, and to the customizability and functional adaptability that characterizes the “A-type” cells.

The resulting housing system has been checked through the detailed design at architectural, structural and energy level of a single-family detached dwelling, in a standard use pattern. This living unit is composed from a day/night room, flanked by a toilet box on the one side and by a kitchen box (coupled with technical plants casing) on the other side.

The timber bearing structure is framed in the “A-type” cell, and it is plated in the “B-type” cell. This structure is clad from the building envelope components, that is multilayer panels and windows, so to make complete the living unit.

All the building components have been sized in order to be carried through one or more containers “High Cube 40”, having 40 foots length (equivalent to 12,20 m).

Consequently, it is possible their carrying by cargo ships, freight trains and camions. This potentiality highlights the “mounting box” concept as intrinsic property of the Living Box.

The system assembly can be summarized in eight steps:

1) placing of the foundation curbs (built in reinforced concrete, also in prefabricated curbs removable at end-life);

2) placing of the foundations timber beams, over the foundation curbs;

3) placing of the foundation timber slabs, fixed on the foundation beams;

4) placing of the “B-type” cells;

5) placing of the “A-type” cells bearing structure;

6) placing of the roof covering;

7) placing of the walls (multilayer panels) and the windows;

8) completion with internal and external optional components.