Mass Customisation and Sustainability in Housing
ZEMCH2014
INTERNATIONAL CONFERENCE
4th - 6th June 2014
Londrina - Paraná - Brazil
Livingbox Modular Habitative Unit
Antonio Frattari
Civil Environmental and Mechanical Engineering Department,
University of Trento, Italia
Abstract
Introduction
Modular home transportation
Modular home typological solutions
Modular home customization
Modular home constructive solutions
Modular home environmental impact
Modular home bioclimatic solutions
Modular home thermal efficiency
Modular home building automation
Modular home prototype
Conclusion
References
Abstract
The project of a minimum expandable living unit: LIVINGBOX has been developed at the Laboratory of Building Design of the University of Trento (Italy). It can be used as a minimum dwelling for two people (40.50 m2) or as a hotel room (18 m2 + optional spaces) finished in every detail: interior finishing, furniture and technological systems.
The furniture is integrated in walls and the inner space is flexible and changeable. The furniture, the inner spatial organization and the inner and outdoor finishing are customizable. The modular home is built joining two precast modules. The dimensions of a single module are cm 249 x 999 x 300. LIVINGBOX has been designed to minimize the impact of the building on environmental matrixes: water, air, soil. The materials used are natural, recyclable or recycled. It is characterized by extensive use of wood to limit CO2 emission into the atmosphere and it was designed as Zero Energy House. To reach this target it is equipped with systems for producing energy from renewable sources, so as to minimize use of fossil energy. In addition the modular home is a low consumption building. The envelop transmittance value is between 0.20 and 0.25 W/m2
K, and the thermal lag of 10-15 h. To optimize the relationship between comfort and energy consumption LIVINGBOX is equipped with a modular home automation system. A prototype at real scale has been
built as so to verify the real building possibilities. It was displayed in Milano (Italy) at beginning of October 2013 at the “MADE EXPO 2013”. The prototype was transported by 2 trucks from Roma to Milano to Campobasso (more or less 1500 Km) for testing the effective transportability and we could verify no inconvenience or crack on the interior and on the furniture. This is also a real demonstration that it is earthquake resistant building.
Introduction
Livingbox is a minimum expandable living unit developed at the Laboratory of Building Design of the University of Trento (Italy). It can be used as a minimum dwelling for two people, as an hotel room, a student’s room in University campus, a minimum dwelling for older people in protected structures. It is finished in every detail: interior finishing, furniture and technological systems. Several architects and researchers have developed similar ideas realizing small buildings paying attention to the transportability as Lisa Tilder and Stephen Tirk (USA) or ADD-A-ROOM (Sweden architecture studio). Other architects have paid particular attention to the use of dry constructive systems, such as Taylor Smyts Architects (Canada) or Crayg Chatman (Australia). Very interesting are the works of Jo Nagasaka and Schemate Architecture Office (Japan) or of Rintal Eggertsson (Richardson 2011 and Zamora, Sanchez and Paredes 2010).
During the design phase we paid attention to all these characteristics. One of the main features of Livingbox is the customization. The furniture of the prefab modular home is customizable and integrated in the walls so that the inner space is flexible and changeable during the day (living room, study, single or double bedroom). The outdoor walls are customizable with different constructive solutions. As example, they can be coated with different materials or to be built with different thickness of the insulation. One of the other most important aims of this prefab design is the zero energy consumption. This target has been reached by combining the bioclimatic solutions with the good thermal behavior of the modular unit achieved with the constructive solutions, following the main criteria applied in the buildings realized for the "solar decathlon".
Modular home transportation
The modular home is built joining two precast industrialized basic modules (Fig. 1). One is specialized and equipped with the bathroom and the kitchen including pipes, heating pump, tank, heating system, electrical system, control devices panel and touch screen for managing building automation. The second is free and available for any functional attribution (Kaufmann and Remick 2009 and Knaack, Chung-Klatte and Hasselbach 2012).
Figure1: The prototype of the modular habitative unit built with two basic modular modules
The dimensions of a single prefab module are 2.49 m (width) x 9.99 m (length) x 2.99 m (height). With these dimensions (Fig. 2), it can be transported, for the Italian code of the road traffic, with a truck trailer without being classified as a "special cargo". It can also be transported by railway wagons to minimize the CO2 emission.
Figure 2: The two basic modular modules
Modular home typological solutions
The modular home is articulated in a fixed block kitchen-bath and in a large multi-purpose space that can be articulated during the day. The modular home can be expanded from 40.50 to 60.80 m2 net. In this last case the kitchen and the bathroom block are bigger (Mira and Minquet 2012 and Smith 2010). The units can be put together for generating terraced modular houses or block houses up to three floors. The living unit can be organized functionally also in different way (Fig. 3).
One example could be the solution as hotel. In this case the space is articulated in a room of about 15.00 m2, in a multi-functional space between the bedroom and the bathroom access, about 5.00 m2, equipped with a wardrobe (length 2.40 m), and a bathroom, about 5.00 m2. The units aggregation can generate different types of buildings: terraced houses, blocks up to three floors, or small settlements with the units
spread over the land.
Figure 3: Different modular typological solutions
For its typological flexibility, the modular home could be structured as a part of different building, maintaining the base concepts of transportability and modularity. It is possible to redesign the inner space realizing different typological solutions. For example, Livingbox could be used as a core modular unit for open-air restaurants, coffee shops, etc. The free aggregation of several units can realize resort and small settlements. Due to transportability, it can be used as emergency housing after earthquakes or catastrophes. At the moment, the idea of building resorts that, in case of emergency, can be moved into a crisis area in few days is being developed. So it could be possible to have emergency prefab buildings in a few days, and at the same time do not store a large quantity of small manufactured components or tents to use in the case of crisis – this is what several nations are doing at the moment. A small quantity of tents can be used during the first week after the event and then, moving the buildings from the resort, it is possible provide more comfortable living, while waiting for the reconstruction. A negative example: after the last Aquila’s heartquake the population had to live for more than 7 months in tents waiting for new wooden houses.
Modular home customization
Modular home can be customized from different points of view: constructive, technological and furnishings. The layout of the Livingbox walls and floors has been thought to follow the user needs for what concern the inner comfort. It means that it is possible to modify the layouts of the walls maintaining the same wooden panels. As example there is the possibility to maintain the insulation material modifying the thickness or changing totally the material. Significant, for what concern the last one situation, it is possible to have the
external finishing as ventilated wall, or plastered. It is also possible to use rock wool instead sheep wool for insulation. This last choice, as example, could be related to the request fire resistance of the wall. In other cases, economic evaluations could be the basis for different choices. The cost of the unit can be higher or lower depending for the different solutions starting from the basic solution able to ensure the right comfort.
Several solutions have been thought to customize the unit improving the basic version, maintaining always the "concept" without modification to the basic structural solution. For what concern the heating an heat pump (COP=3.8), eventually powered by photovoltaic system (PV), is the base of the heating ventilation system (HV) and the production of sanitary hot water (SHW). At same time the PV system produces electricity for the artificial lighting and for all electrical devices. The water for sanitary use could be harvests from an integrated filtering system connected with the roof garden. Other step towards the customization is the introduction of the building automation to manage the different scenarios for the entertainment and for saving energy managing the daylighting, the heating and the natural ventilation. Equipped with the building automation and realized with sustainable solutions the modular unit is a “smart home”. In this case it could be connect to other similar modular home equipped with analogous system for sharing information and energy and/or with the public net as part a smart district.
Livingbox modular home could be a possible answer to new living behavior of the people of the developed countries and to the needs of the people of the developing countries (Bergdoll and Christensen 2008). For what concern the developed countries we can see that the family, in the patriarchal or matriarchal concept, is just a small part of the families. The new life style of the largest part of the society is more oriented to an individual existence or to the couple life. The actual women economic independence emphasizes this kind of situation. The young new generation does not need a big home, but they want space easy to manage, enough to ensure all the domestic and work activities (Zamora, Sanchez and Paredes 2010).
Figure 4: Flexibility of the inner environment: the living/sleeping area
For this reason the furniture of Livingbox modular home is simple, integrated with the walls for taking less space, ensuring the possibility to carry out all the home activities (Fig. 4). The home must be small but sometime, must show the social level, for this a customized solution can be the answer and Livingbox could be that right. A big part of the people of the developing countries is moving towards the big metropolis and there is the request of small apartments at low cost. Several municipalities are planning new settlements for social housing. Livingbox could be an answer because the basic version (40.50 m2) is a cheap answer for apartments for two people in four-storey buildings. The bigger solution, 60.80 m2, is right for four people.
Modular home constructive solutions
From a constructive point of view the main characteristic of Living Box modular home is that it is built with load-bearing massive panels: Cross Laminated Panels (XLam). The constructive Xlam solution consists in building a load-bearing panel using three or more layers of boards. Each layer is orthogonal to the previous for offsetting the deformation or the movement of the boards (Schrentewein 2008). These last one are connected by glue, aluminum nails or beech pegs. The connections between the panels are with screws, steel corner plates and “hold-down”. In this way it is possible to build a box with good characteristics as earthquake resistant, free to be finished with different solutions for each kind of customization in terms of energy efficiency, aesthetic solutions or economic choices (Fig. 5).
Figure 5: The construction of the load bearing structure with XLam panels
Modular home environmental impact
The constructive solutions for the modular home have been designed to minimize the building impact on the environmental matrixes: water, air, soil (Friedman 2010). The used materials are natural, recyclable or recycled. The extensive use of wood reduces CO2 emission in the atmosphere.
The wood used embodies around 9.5 tons of CO2 giving a positive contribution to reduction the greenhouse effect. Even the other used materials, mostly recycled, were chosen through a Life Cycle Assessment (LCA) including the aspects that minimize the CO2 emitted in the atmosphere during the construction, maintenance and disposal (Fig. 6). The used software for the LCA is “SimaPro2 and Ecoinvent is the used database. For
several product was used the Environmental Product Declaration (EPD).
Figure 6: The LCA results of the LCA for the external walls
All constructive solutions combined with the architectonic choices have been studied to reduce the environment impact trough the best exploitation of the free contributions offered from the surroundings in terms of solar and wind contributions to produce clean energy.
Figure 7: The constructive solution for the garden roof
The roof could be a “garden roof” to reduce the energy losses and at same time to minimize the heat island effect. It could be integrated with different systems for producing energy from renewable sources, as a solar active system or a small wind turbine, in order to minimize the fossil energy consumption (Fig. 7). A PV system can be integrated in the roof. With 16 modules and a surface of 20 m2 it is possible to produce
5368 KWp/a. The heating is achieved with heat pump that produces also the sanitary hot water. All these constructive solutions make of Livingbox an Active House that uses the energy produced by itself giving the extra production to the net or to other users. The total energy demand of the modular house, calculated with Design Builder software, is 1181.11 kWh/a, articulated in 260.00 kWh/a for the lighting, 660.28 kWh/a for the heating and 260.83 kWh/year for the sanitary hot water. The positive balance is 1910.82 kWh/a of extra production. The consumption index for the different typologies are: lighting 6,42 kWh/(m2 x a), heating 16.30 kWh/(m2 x a), SHW 6,44 kWh/(m2 x a). The calculation have been developed simulating the building at Bolzano (Italy), lat. 46°29'53" North, long.11°21'17" East.
The materials employed such as the paints are low-emissivity. An example in this direction is the water paint with acetic acid for aging the larch of the interior fittings or of the battens wooden finishing of the outer walls.
Modular home bioclimatic solutions
The modular home's energy independence is improved upon even by design solutions that maximize the free contributions from the surroundings: solar screens, passive solar systems for SHW, mini-greenhouse, on the south façade, to assist in the winter heating and the natural ventilation for summer cooling. Livingbox is opened to the south, totally closed, without windows, on the north front and partly opened to the east with a screened window to minimize the negative sun in summer (Fig. 8).
Figure 8: Sketch of the sun and wind exploitation
Roof and walls could be ventilated to decrease use of insulating membranes and to ensure the natural breathability (Roaf, Fuentes & Thomas 2003).
Modular home thermal efficiency
The low consumption of the modular home is enhanced by the customizable envelop stratigraphy that can ensure a transmittance value between 0.20-0.25 W/m2 K, and a thermal lag between 10-15 h. The energy demand for the heating, with these constructive solutions, is 16.30 kW/m2 x a).
Particular attention has been paid to the prevention of the thermal bridges realizing a continuous insulated envelope in rock wool (Fig. 9). This thermal efficiency is approaching that of a "Passive Envelope" inspired by the “Passive Haus”.
Modular home building automation
Livingbox is equipped with a modular home automation system to optimize the relationship between comfort and energy consumption. This allows the lighting and the heating, the daylighting, the shading and the natural ventilation to be managed with integrated modular packages.
The scenarios are customizable for the different users and they can be activated from remote. In this way when the user will come home he will have the best inner environmental conditions. At same time the user can manage manually the different functions.
Modular home prototype
A real scale modular home prototype has been built so as to verify the building possibilities. It was developed as one of the possible variants at the "top" level. The prototype was built partially in Rom and finished in Milano for logistic solution (Slawik, Bergmann and Buchmeier 2010).
The walls are in load bearing Xlam panels with glued boards and have a thickness of 90 mm. The same kind of panels, with the thickness of 90 mm, are used as load bearing elements for the floor and the roof. The connections between the panels are made by screws (220 mm), steel angle plates (90x120x240x20 mm), hold-down (90x100x200x20 mm). The rear wall is plastered. The two lateral walls are ventilated finished with aluminum shingles. The layers of the external ventilated walls from inside to outside are: gypsum board (15 mm), sheep wool (50 mm), XLam panel (90 mm), mineral wool (80 mm), cement board (13 mm), aluminum shingles (5/10 mm). The layers of the plastered wall are the same; instead of the external aluminum shingles there is plaster. The roof stratification is from inside to outside is made up by the following layers: gypsum board (15 mm), XLam panel (90 mm), mineral wall (80 mm), boards (20) mm, (2)” roofingreen
system” (120 mm).
The floor stratification is from inside to outside: wooden pavement (14 mm), spruce boards (20 mm), mineral wool (80 mm), Xlam load bearing panel (90mm), expanded clay (90 mm), bituminous membrane (8 mm).
The stresses received during the transportation between Rom and Milano were comparable with at least 15 of the Aquila's earthquake in 2012, and with several lighter earthquakes. After the trip the prototype did not present cracks (Fig. 10).
Figure 10: The arrival at Milano’s building site
Figure 11: Livingbox at Milano’s Expo
The modular home was displayed in Milano (Italy) at beginning of October 2013 at the “MADE EXPO 2013” (Fig. 11). At the end of exhibition the prototype was transported by 2 trucks, from Milano to Campobasso (more or less 900 Km) and it was possible to verify no inconvenience or crack in the interior and furniture (Fig. 12). This was a new demonstration that the building effectively is earthquake resistant.
Figure 12: The first stage of the modular home transportation from Milano to Campobasso
Conclusion
Living Box modular home is a concept, not a single project. It is possible to have more answers designed on the basis of a conceptual singular solution. In this way it allows to have an analogical serial production that allows costs to be reduced, but at same time to have a quality product accessible to different economic possibilities. Through the prototype it was possible to demonstrate the applicability of the concept in a real case showing the main characteristics of the building: the feasibility, the transportability, the earthquake resistance, the efficiency of the building automation in management of the home. Now the modular home prototype will be used to test the real thermal and acoustic behavior and the efficiency of the building automation for energy saving.
References
BERGDOLL, B., and CHRISTENSEN, P., 2008, ‘Home Delivery: Fabricating the Modern
Dwelling,’ The Museum of Modern Art, New York.
FRIEDMAN, A., 2010, ‘Narrow Houses: New Directions in Efficient Design’, Princeton
Architectural Press, New York.
KAUFMANN, M. and REMICK, C., 2009, ‘PreFab Green,’ Gibbs Smith Publishers,
Layton.
KNAACK, U., CHUNG-KLATTE, S. and HASSELBACH, R., 2012, ‘Prefabricated
Systems: Principles of Construction,’ Birkhäuser, Berlin.
MIRA, O. and MINQUET, J.M., 2012, ‘Contemporary green prefab: Industrialized & Kit
Architecture’, Instituto Monsa de Ediciones, Barcelona.
RICHARDSON, P., 2011, ‘Nano House: Innovations for Small Dwellings’, Thames &
Hudson, London.
ROAF, S., FUENTES, M. and THOMAS, S., ‘Ecohouse 2: A Design Guide’, 2003,
Architectural Press.
SCHRENTEWEIN, T., 2008, ‘Casaclima : costruire in legno’, Raetia editore, Bolzano.
SLAWIK, H. and BERGMANN, J. and BUCHMEIER, M., 2010, ‘Container Atlas: A
Practical Guide to Container Architecture’, Gestalten Verlag, Berlin.
SMITH, R. E., 2010, ‘Prefab architecture: a guide to modular design and construction’,
John Wiley & Sons Inc, New Jersey.
ZAMORA, M.F., SANCHEZ, V.A. and PAREDES BENITEZ, C., 2010, ‘Small Eco
Houses: Living Green in Style’, Universe, New York.