Integrating processes and teams – a key for achieving sustainable buildings
This insight and many others were given during the DIRECTION final event which brought together experts from the field of sustainable buildings to share the outcomes of the four years of work.
Hosted on 17 February 2016 by the Technische Universität München (TUM), in Munich, Germany, the event was also designed to target future architects, developers and engineers including master and doctoral students. Julia Vicente from DIRECTION coordinator CARTIF gave an overview about the project, the demo sites, the partnership and the ambition to bring energy consumption under 60kWh/m2/ year.
Three consecutive roundtables tackled the major outcomes of DIRECTION. The first roundtable was chaired by Carlos Bárcena from Dragados and brought in Oliver Vietgen from Domagk, Michael Krause from Fraunhofer IBP and Ulrich Filippi Oberegger from EURAC . Focussing on the Smart and integrated design-construction-management process, Carlos introduced the current state of affairs. He emphasised that “…despite the construction industry’s capability of delivering complex and novel projects, conventional construction processes tend to be highly inefficient. These are often largely sequential and separated, and the structure of the industry is sustained on a contractual and confrontational culture”.
A mitigating factor would be to focus more on meeting the needs of the end-user, which would lead to more integrated processes. At the DIRECTION demo sites, designers worked in close collaboration with the other partners so that their creative and analytical skills were used to best effect in the project delivery as a whole, and not only in the final building design. Designers, constructors and suppliers need to work together across the whole value chain.
Other important factors in the process are product development and building life cycle. Product development requires detailed knowledge of clients and their aspirations, a factor which is particularly borne in mind with the processes implemented during the project. Designers need to integrate the costs of the whole life cycle, including costs of energy consumption and maintenance. Simulation models to measure end-product performance before and after actual construction are highly recommended. Wrapping up this first roundtable, Carlos concluded: “We must bear in mind that real change will not just be about getting the construction partners to meet the client’s demands, but also about pushing back the boundaries of client aspirations” and he continued “We need to make sure our products incorporate the most innovative and efficient technologies, and that the client will be willing to invest in these technologies.”
The second roundtable examined how to control costs during the building and operational phases. It was chaired by Oliver Vietgen from FACIT and was composed of Sergio Sanz CARTIF, Norberto Gonzalez Hildalgo 1AI, Alexander Alber BLS, and Carlos Bárcena Dragados. Oliver started the discussion by asking “Why control costs at all?” From the perspective of sustainable buildings designers, controlling costs help to generate reasonable profit or to avoid financial loss for the client. It can affect building characteristics and end-users’ business models.
How to estimate the costs? At the DIRECTION demo sites, the cost estimation tools focused on energy costs as these were key to the project. Energy building simulation played a central role at the German demo site as a decision-making tool. As an example, Oliver described the decision about the window sizes on the north façade: “At NuOffice, (we discussed) from an energy efficiency point of view, that small windows were desirable to reduce potential heat loss and increase sunlight capture; from a functional point of view, large windows were preferable to provide optimum day light in all working areas independent of their size and layout; from an economic point of view, identical window sizes on all facades (North, South, East West) were considered to reduce the overall production costs of the product.” In the end, the decision on the quality and quantity of windows was largely based on the energy simulation model, strongly influencing the final design.
Oliver highlighted the unique selling point of the NuOffice in an extremely competitive environment “By reduced operating costs in comparison to competitors we were able to offer an appealing ancillary leasing cost flat rate for the tenants which includes heating, cooling, electricity in all public areas, electricity for HVACR and lifts”. A similar approach was adopted for the Black Monolith in Bolzano. Alexander reported “We had a similar approach that goes even further. All public and private tenants will pay a leasing cost flat rate which includes energy and other ancillary fees in the unit within a service contract. This flat rate could be adapted once real consumption is known, for example after one year. The upside is the cost guarantee for tenants, and the downside is the risk of unfavourable cost variance for public renters.” During discussion, it was underlined that calculable constant costs are attractive for the end-user but not always feasible.
Ulrich Filippi Oberegger from EURAC chaired the third roundtable. It included Norberto Gonzales Hildago from 1AI, Julia Vicente from CARTIF, and Jan Kaiser from Fraunhofer IBP. It looked into Key Performance Indicators (KPIs) for building performance, economic analysis and commissioning. In DIRECTION, the following KPI’s were monitored in real time: thermal comfort, air quality, delivered energy, energy needs, and primary energy and CO2 emissions. With these indicators, the performance of the building could be monitored. As Jan explained “During the planning, we set the requirements for the building’s performance. At this stage of our project, we are now collecting data to evaluate whether the building meets the desired requirements. These pre-defined indicators are also necessary to make the data comparable to those of other buildings.” Norberto adds “Values to use are energy per square metre per year, as well as profitability relating to energy efficiency measures. The latter should be of particular relevance to public contracts. Other suitable indicators are those which are capable of ensuring correct execution, for example in order to avoid thermal bridges.”
The discussion challenged some major issues of the use of KPIs, such as whether the extra efforts for commissioning and monitoring low energy buildings do pay off, or whether low energy consumption is compatible with a high level of comfort. KPIs should always include client satisfaction. The question of standardising KPIs at European level or variable from country to country remained open. A possible starting point could be to identify the right energy and quality indicators, suggest several value references that are not too restricted to facilitate their implementation, along with a series of simple certifications to ensure achievement of the nZEB goal.
At the end of the afternoon, Dr Roland Göttig from Lehrstuhl für Bauphysik (TUM) presented two theses prepared by master candidates at TUM. These dealt with technical solutions for the NuOffice, “Utilization of Renewable Energy – Calculations according to German Energy Regulations and DGNB-LCA” and “Examination of the HVAC-Systems – non-steady ». Both were applauded as adding interesting analysis to DIRECTION.