The wooden beams are worked using the Festool one-handed planer

Living more fairly – building more sustainably

Three students in Vienna are developing a modular concept for construction and living for the residential constructions of the future. The construction materials are sustainable and the idea seems intelligent – but can the concept really be put into practice? We've asked the three creators.

Creators of the vivihouse project

Paul Adrian Schulz (left), Nikolas Kichler (centre) and Mikka Fürst (right)

Nikolas Kichler (NK): Architecture graduate from the Vienna University of Technology (TU Wien)

Mikka Fürst (MF): Architecture graduate from TU Wien, course for sustainable construction at TU Wien and TU Graz

Paul Adrian Schulz (PAS): Architecture graduate from the Academy of Fine Arts in Vienna

How did the idea of the vivihouse come about?

Nikolas Kichler: Collaboratively constructing several storeys, as well as building in an environmentally friendly way – that was our motto from the beginning of our project. We wanted to use it to find an answer to the growing challenges in urban housing. The residents can contribute to the development of their own building. This means that buildings will be constructed that make sense in the long term, are suitable for daily and changing needs and can be better maintained.

What's behind the name "vivihouse" and what is special about this modular construction design?

NK: "vivihouse" comes from "convivial", meaning "full of life". What's special about it is the combination of natural raw materials, such as wood, straw and loam. Up to six storeys are possible with our modular concept. Thanks to the identical and simple module design, even a kind of DIY is possible in prefabrication for the construction. The modules can be recreated by following the instructions on the website, together with professional guidance. Everything that we build can be fully dismantled and is traceable back to nature. This way, we are doing our bit to ensure the planet is still habitable for future generations.

The construction plans for the vivihouse concept

What are the challenges of building modular houses with over more than one storey?

Paul Adrian Schulz: We see the biggest challenge in logistics, assembly and environmental compliance with fire safety and soundproofing regulations, as well as airtightness and impermeability to driving rain. Another, more general challenge is finding suitable and affordable land.

Who monitors the quality of individual modules and the structural analysis?

NK: The project was conceived such that the outer walls and ceiling elements can be easily assembled. Our workshops are always attended by experts. Since the building is based on prefabrication methods, the elements can easily be checked and removed by maintenance groups. The joints relevant for the structure, as well as the struts, reinforcements, utilities management and the assembly process of the entire building were exclusively carried out by qualified professionals in the case of this prototype.

Insights into the construction design of the vivihouse project

Which Festool tools are particularly popular with the users?

NK: The most important connecting element in vivihouses is the screw, so the Festool cordless screwdrivers are particularly popular in our construction processes, which also have enough power for long screws. The clean, precise cuts made by the plunge-cut saw are also very much appreciated.

Pieces of wood are cut using the Festool portable circular saw

What is your vision of urban living in the future?

Mikka Fürst: Soil sealing and increasingly scarce areas for habitation play a significant role in our vision. Soil sealing should only happen on surfaces where it is absolutely necessary. More and more people are using their time to discover, of their own accord, what they need to live a good life and are making this a reality together.

What role does sustainability play?

MF: A huge one, of course – on all levels: On the environmental level, through the use of renewable raw materials, energy efficiency and reusability of construction elements; and on the social level, through interpersonal relationships which can be created through different forms of participation. The environmental components are ultimately reflected in energy efficiency, construction costs and the longevity of construction elements that maintain their value.

Can modern architecture be combined with sustainability?

MF: More than a third of total CO2 emissions can be traced back to the construction and use of buildings. In order to reduce emissions from the construction sector efficiently, there's nothing else left to do but make sustainable construction tomorrow's modern architecture. That means that sustainable factors should be taken into account at an early stage of the design process, and we need to move away from problematic solutions.

What role will the environment and sustainability play in the construction industry in the future?

MF: In the future, it will probably no longer be possible to build without more in-depth environmental considerations. So we'll have to focus more on raw materials that don't generate waste and only require low quantities of energy to manufacture. We will consider the entire life cycle and ensure that buildings are themselves capable of supplying the energy required to keep them running.

Which materials are mainly used?

MF: The basic elements are mainly made of spruce glued-laminated timber, which we source from Austrian companies from local forests. The façades are currently insulated with straw bales and the inner surfaces are sealed with loam rendering. Cement is only used in the foundations. We completely avoid using insulating materials such as styrofoam and styrodur.

Who are your customers?

NK: People with an environmental conscience and an interest in participation and design.

Do you have technical training?

NK: No, not per se. However, all three of us have worked as assistants on construction sites – primarily in construction using straw bales.

The Festool portable circular saw in operation

How much room for creativity is there in the concept of the modular construction kit?

PAS: In the layout design, the only thing that has to be taken into account is the struts, meaning the vivihouse is suitable for a wide variety of uses and ideas. Furthermore, almost any arrangement is possible for the façade and ceiling structures – depending on your tastes, availability of local materials, the local climate and technical tools available.

Are there assembly instructions or how can it be envisaged?

PAS: Yes, in our workshops we've combined lists of materials with information about types of screws and assembly instructions, for example. This increases autonomy and significantly reduces susceptibility to errors for participants in the workshop. The instructions are additionally available online for anybody to access.

How difficult is it to construct a module like that? Can a layperson do it without professional help?

NK: Our workshops always begin with tool and safety training. The next steps are then demonstrated using our assembly instructions. Our workshops are always run with professional help. People who are interested can join in with construction, or simply watch it being built or help in a different way. There is usually enough to do. Our first prototype was primarily built by architecture students. Almost 20% of the contributors were external people who were interested, including experienced tradespeople.

Can the "experience of living" in a vivihouse be compared to a conventional house? Including in terms of energy efficiency?

MF: The feeling of being surrounded by natural materials is an experience in itself that many people are no longer familiar with. That was one of the reasons why we decided to build a prototype. For example, to make it possible to experience the moisture regulation effect of the loam rendering. It's an opportunity to show urban dwellers an affordable, healthy and sustainable alternative.

How much does it costs to build a single module and how is the entire construction financed?

NK: A façade element in our prototype can cost between 3000 and 4000 euros gross. It very much depends on the size and type of the windows, for example. The outer wall costs between 300 and 400 euros. These calculations also took into account the labour costs of the participants. Our first three-storey prototype was made possible through financial support from the Austrian Climate and Energy Fund, private grants from suppliers, and industrial sponsorship.

What are the future plans for vivihouse?

NK: Assembling a vivihouse costs time if the residents are working on it. However, that can reduce costs. But we can imagine that, in the future, the vivihouse concept could even work as social housing in the long term. It promotes inclusion and is an environmentally friendly version of the housing of the future.