Up to half of a building’s energy consumption is “locked” into the design, shows a new research collaboration between architects and engineers. The geometric shape of buildings and the influx of daylight are among the key parameters for reducing energy use.
By Jan Aagaard, Focus Denmark no 4, 2012
For many years, sustainable buildings have primarily been a matter of technology. To create buildings that use as little energy as possible, architects and engineers have focused on technological solutions like thicker insulation, lowenergy windows, sunscreening and ventilation.
This approach is worth reviewing however, as new Danish research shows that 40–50 percent of a building’s energy consumption is “locked” into the design. In other words, a building’s design, and the materials of which it is made, limit what can later be achieved in energy savings by means of technology.
Umeå School of Architecture in Sweden has been designed by Henning Larsen Architects, who are
known for making active use of daylight in buildings. Photo: Åke E:son Lindman.
Henning Larsen Architects has conducted research into how design parameters such as daylight, geometry and positioning can be used to create buildings which are both beautiful and energy-efficient.
“Architecture can in itself save energy, if knowledge is properly applied. If energysaving solutions are incorporated into a building from the start, it will be a genuine low-energy construction. These solutions will not become antiquated. It is simply better architecture,” says architect Signe Kongebro, who heads the sustainability department at Henning Larsen Architects.
At the new Danish headquarters of healthcare company Novo Nordisk, the geometry of the building, the influx of daylight and the positioning of the building’s functions will play significant roles in energy consumption. Illustration: Henning Larsen Architects. Novo Nordisk
Theory meets practice
For the last four years, she has been in charge of an unconventional research and innovation collaboration where staff from Henning Larsen Architects have worked with postgraduate engineers at the Technical University of Denmark (DTU). The aim has been to examine the connection between design and energy consumption in buildings.
The engineers conducted “live” research and influenced a number of architecture projects, most of which have been constructed or are under construction. In addition to three doctoral dissertations, the cross-disciplinary collaboration has resulted in a book Design with knowledge. Through articles and cases, the book presents the results, analyses and methods that enable sustainability to be used as a design parameter.
One of the book’s main conclusions is that the best results are achieved when architects and engineers work closely together in the early design phases so that the latest developments in climate and energy science are incorporated in the creative processes.
“Right from the introductory design phases, we need to ensure that a building does not use more energy than necessary. That is the cheapest way to minimise energy consumption, and in future it will be essential. Sustainability requirements are becoming stricter, and these challenges cannot be met by means of technology alone,” says Kongebro.
An important aim of the research was to identify the design parameters with the greatest potential for reducing energy consumption in buildings. The three most important parameters in this respect were identified as the geometry of the building, the influx of daylight and the positioning of the building’s functions.
“Sustainability requirements are becoming stricter, and these challenges cannot be met by means of technology alone,” says Signe Kongebro, head of the sustainability department at Henning Larsen Architects.
The power of daylight
Making active use of daylight in buildings has been one of the trademarks of Henning Larsen Architects since the worldrenowned architect established the firm more than 50 years ago.
“Architecture is the balance between space and light, and daylight is the strongest means to create value for architecture,” states Design with knowledge. Daylight has a prominent role in most of the projects that the book describes.
“The research on which the book is based has shown that daylight is not only an architectural tool, but also one of the best means of reducing energy consumption and CO2 emissions. Used in the right way, daylight reduces the need for artificial lighting and extends the area that can be used. It also has importance for our health and well-being,” says Signe Kongebro.
One of the projects is the new Danish headquarters of healthcare company Novo Nordisk, where the geometry of the building, the influx of daylight and the positioning of the building’s functions play significant roles in energy consumption and sustainability.
The new domicile, which will house the global company’s executive management and 1,100 administrative staff, is designed as a cylindrical six-storey building with an atrium and a spiral staircase at the centre – inspired by the complex structure of the insulin molecule, which forms the foundation of Novo Nordisk’s business.
The cylindrical building has a smaller surface area in relation to its volume, and this helps reduce heat loss and increase the influx of daylight. Three deep recesses in the facade, together with the central atrium, bring the daylight right into the centre of the building.
The building is divided into two indoor climate zones. In the central atrium, the indoor climate varies according to the season of the year. The workplaces on the other hand have a stable indoor climate with local climate zones that can be regulated individually.
“Using different zones that are adjusted to actual needs saves a lot of energy, while creating a pleasant indoor climate,” says Kongebro. If rooms that are not in continuous use, such as meeting rooms and stock rooms, are placed on the sunny side of the building, while workstations are placed on the shady side, the need for mechanical cooling is reduced.
In the Novo Nordisk case, the sustainable elements in the design enable annual energy consumption per square metre to be reduced from 95 kWh (the standard for a conventional new buildings in Denmark in 2008, Ed.) to 71 kWh. By further optimising the building with special glass panes and movement-activated LED lighting, the annual energy consumption per square metre can be reduced to less than 42 kWh (requirement for low energy buildings in Denmark from 2015, Ed.).
In 2011, Henning Larsen Architects won an international architectural competition to design German engineering and electronics company Siemens’ new global headquarters in Munich.
Sustainable urban planning
Incorporating sustainability into the design phase is not limited to the building itself. It can also be incorporated into the planning of cities and districts, as several cases in the book demonstrate.
In a project for a new financial district in Saudi Arabia’s capital Riyadh, Henning Larsen Architects created a comfortable micro-climate in the extremely hot desert environment.
By designing the new district in a profile that is highest towards the centre and lowest towards the edge, hot winds and sandstorms are led above and around the area. A dense structure at the centre provides plenty of shade, and by using light facade materials that maintain humidity, the outdoor temperature can be lowered by 6–8°C (11–14°F).
In northern latitudes, the climatic challenges are very different. Light is much more sought-after than shade. In an urban development project in one of the most densely built quarters of Copenhagen, Henning Larsen Architects have focused on creating better daylight in the existing housing stock.
By removing whole blocks so that the streets become wider, daylight can reach the lowest floors. The buildings are also being renovated with “solar design”, where for example the facades are angled to receive more light, and the windows are replaced with larger panes to allow more daylight into the apartments.
“Through their involvement in our projects, the researchers have shown that urban plans and master plans have far more importance for the energy consumption of cities and buildings than we thought. There is great potential in focusing on more daylight in the planning of cities,” says Signe Kongebro