Sustainable buildings using modular construction
What building sustainably means
Sustainable building means considering the building as a whole, from planning through the use of resources to its energy-efficient use. In all phases, the priority is to combine the interests of the environment, society and business as efficiently and as viably for the future as possible. However, the sustainable construction of buildings is often only associated with energy efficiency during operation and use of the building, and the building’s life before and after this is ignored. But the manufacture of building materials in particular along with the construction and dismantling of a building consume vast quantities of energy. In order to assess sustainability in building, it is therefore important to consider the entire life cycle – from integral planning through manufacture, use, multiple changes of use to dismantling – and to minimise the consumption of energy and resources.
As a corporate group, we base our actions on the three aspects of green building, which are founded on the three pillars of sustainability. These aspects are based on the concept that sustainable development can only be achieved if environmental, commercial and social goals are implemented with equal weight and at the same time. For us, this means implementing this approach in the planning and construction process and further developing it in order to promote sustainable development in the building industry and to set a standard for the responsible handling of resources.
The 3 aspects of green building
The ecological aspect covers the protection of the environment and nature. For the building industry, this means reducing the carbon footprint of its buildings, by using environmentally compatible materials, for example, and showing awareness when dealing with finite raw materials.
The economic aspect considers the efficiency of a building during its complete life cycle. This means, firstly, implementing lean production methods in order to use raw materials efficiently and avoid waste and, secondly, using integrated costs management based on a life cycle cost analysis to ensure the cost efficiency of a building project.
The third pillar focuses on social sustainability and thus on people as the users of the building. It includes comfort, with social values such as a healthy living environment, quality of life and attractive design also featuring here. Aspects such as accessibility and the safety of users are also crucial.
Aspects of the ecological quality of modular buildings
To achieve the maximum possible length of use of a building, it must be possible to reuse it. Reusing a building several times reduces the consumption of land for new buildings. One of the crucial criteria with modular buildings: Thanks to their self-supporting steel frame structure with non-loadbearing internal walls, they are very flexible and can be converted, enlarged, reduced in size or given a change of use.
The basic principle of lean production is to minimise waste. All the processes during the prefabrication of the modules are optimised and harmonised, so that optimum use is made of all resources – material, personnel and energy. This reduces the use of resources by 36% and cuts waste by 70% compared with conventional building. The high level of prefabrication of the modules also reduces pollution of the environment by dirt, noise and building waste on site to a minimum. In figures, this means: up to 20% less site traffic and a reduction in noise and building dust by up to 50%.
Steel is the most recycled material worldwide. For example, 99% of building steel is recycled, 88% of which is melted down and turned into new steel. It can therefore be said that, today, essentially every steel product – and thus the basic structure of the steel modules too – is already a recycled product. Steel recycling means that more than 20 million tonnes of CO2 emissions per year are avoided in Germany alone. This is as much as Berlin releases in a year.
Thanks to the integral planning, modular buildings are designed for optimum energy efficiency. Modular buildings can be designed at anything from the KfW 55 efficiency standard through to energy-plus buildings. As part of the “100 EnergyPlus Houses for Dortmund” campaign, 17 residential units which produce more energy than they consume were built by Lake Phoenixsee in Dortmund, plus a modular daycare centre, which naturally meets the same energy requirements. ALHO produced the concept for the EnergyPlus house in collaboration with a thermal engineering and energy technology firm. The requirement to produce an energy surplus of 1,000 kWh/a was actually surpassed.
If a modular building is no longer needed, it can be completely dismantled and then sorted at the factory into its individual component materials. All materials can thus be approx. 90% recycled and returned to the material cycle.
Aspects of the economic quality of modular buildings
The structure and building technology are carefully coordinated in the integral planning process, in contrast to what happens in the traditional planning process. Alongside the building and technical trades and specialists, all the life cycles of the building, plus costs, user comfort and ecology will already have been taken into consideration.
The modular construction method follows the principle of the circular economy. It is thus possible to remove a modular building completely by dismantling it into its individual modules. These can then be reassembled in a different location (“mobile real estate”) – or else the modules can be returned to the factory.
Aspects of the social quality of modular buildings
Healthy living environment
Modular buildings are very comfortable to use and provide a pleasant living and working environment. The optimised insulation creates a pleasant room temperature – cosy and warm in the winter, pleasantly cool in the summer. The double-shell wall and ceiling system provides maximum sound insulation and the best acoustics. Floor-to-ceiling windows bring daylight into the building, creating a feeling of well-being. As a matter of principle, only quality-tested materials made by German brand manufacturers are used in the construction of ALHO modular buildings – providing extra security and ensuring a high quality of air inside the rooms.
Naturally, ALHO modular buildings can be planned for full accessibility according to DIN standards. For this, our customers can make use of DIN-certified specialists in accessible building within our in-house planning team.
ALHO modular buildings – certified as sustainable by the DGNB!
ALHO supports the values and principles of the DGNB and hopes that its membership will help promote sustainability in building. The DGNB has made it its mission to make the public aware of sustainable building methods. For this reason, the DGNB certifies buildings that can be proven to be sustainable. At ALHO, it is not just a single building that has been certified; an entire construction system has received the DGNB Multiple Certificate of Sustainability in gold as proof of its sustainable building methods.
The DGNB certification system for sustainable building is intended to ensure the objective description and evaluation of the sustainability of buildings and accommodation. With DGNB-certified buildings, the quality in the wider sense is evaluated throughout the complete life cycle of the building. The system considers all the major aspects of sustainable building and the sustainability of buildings. Alongside the main themes of ecology, economy, sociocultural and functional aspects from the three-pillar model, the areas of technology, processes and location are also assessed.
The DGNB awards its “Quality Certificate for Sustainable Building” in platinum, gold, silver and bronze. ALHO has been awarded the Multiple Certificate in gold for its building system.