OFSETTING THE NATURE

OFSETTING THE NATURE

offsetting the environment... Design Philosophy The environments we shape for ourselves and our habits of climatizing them are mainly developed in times when we were not yet aware that our energy sources are finite and therefore our existence on the planet is fragile. The concept of sustainability arises as a response to this on-going risk for our future and is mainly perceived as a mere technical response to tackle the energy consumption of our buildings. Even though it is essential to benefit from technology, we should also consider how we use our spaces and what are our habitual reflexes when we are climatizing our interiors. Why do we climatize our buildings as if every corner of it is homogenously used? Can we invent models that would climatically treat differently, to the parts that are used differently? Can we imagine half opening our buildings to the environment by means of half-climatized, liminal spaces? These are the questions that provided the driving principles of our proposal. We aimed to invent a method that looks to our artificial habitats alternatively and from that perspective suggests a solution that combines innoative engineering wıth betterment of our habits of inhabiting offıce spaces. With this combined effort we have managed to reduce the energy consumption of Posthuset by 55-60%. After all, sustaining our existence is not just a matter of rethinking our material usage, but also rethinking our lifestyle.

OFFICES MALL office mass Office mass of Posthuset is treated equally in every volume in terms of its climatization. As a traditional office building, it is fully dependent on external energy to fully climatize its interior and has a thin skin that insulates the climatized surfaces from the outside. concentrating office areas By rearranging the office floor area, all vertical and some horizontal circulation areas are pushed at the boundaries of the building and the office spaces are pushed inside and seperated by a second skin that is offseted from the main skin. This enables the building to only climatize the areas fully where it is used the most and therefore decrease the heated volume dramatically by keeping the used area the same. environmental zone This operation creates a much thicker shell for the building, increases the insulation performance significantly and creates a unique interior quality. The liminal area, which is named environmental zone, is protected but not heated, therefore it is a piece of the environment outside, offsetted inside. new look New shell of the building is landscaped and this is not only used in order to increase the air quality inside but also to express the renovation from the outside, creating a new facade together with its operable windows; clearly marking its openness to the environment, and highlighting its new character. connection with the outside Ground floor of Posthuset is facing a plaza that is currently under used and strictly seperated from the building as a left-over space. expanded plaza new grid dynamic mall By pushing the facade back, the public plaza in front is expanded through under the building, gaining a character that is more integrated with Posthuset. A new grid aligned with the Biskop Gunneru is juxtaposed with the existing grid of the building, introducing a specific directionality to the space connecting it to the plaza more strongly. Mall areas are created inside and outside the building, blurring the difference between the plaza and the mall. This three floor renovation gives the neighborhood a variety of covered indoor and outdoor spaces of various scales which transforms the site into a dynamic combination of mall areas combined with plaza and central hall of the train station.

GENERAL SCHEME 1 ENVIRONMENTAL ZONE environmental zones are eventually a part of the building but are not directly heated, cooled or ventilated. From a technical perspective, the aim of these new zones is to create more compact office zones and to decrease the area in a floor which requires energy. Another technical advantage is these free standing zones will act as a natural insulation zone. Considering a case where the offices are adjacent to the façade, amount of heat loss and air infiltration are expected to be high, which would cause an increased energy demand. However, when there is a buffer zone in between the façade and the actual office spaces, the heat losses will be reduced as the buffer zone will already be warmer than the outside. 2 SECOND BUILDING SKIN the major renovation on the façade will be the removal of the concrete elements and replacing them with glazing material. The thermal performance of the glazing will be similar to the one currently being used. However, the way we define the façade is more likely an entire outer shell. Our outer shell is composed of the renovated façade (app. 70 mm), the environmental zone (thickness of 2 meters) and glazing separating the office zone with the environmental zone (single glazing, 6 mm). 3 CONTROLLED HEAT LOSS With the introduction of the new air tight office zone, the aim is to decrease the thermal bridges and air leaks from the outer façade. Considering the new outer shell as the new facade, the U-value has changed from 1.5 W/m2K to 0.13 W/m2K. Within this shell, a degree of heat loss is tolerated from the first skin to the environmental zone, in order to climatize the area close to the office skin. 4 SUMMER VENTILATION During summer, natural ventilation will be used more frequently. In order to bring the outside air to the building interior we planned to implement windows at the north and south facades. However, to avoid high levels of ventilation, the windows will be controllable. Considering the frequency of the wind direction in Oslo (mainly from Northeast or Southwest) the wind flow cannot penetrate into the building without losing its speed. Reduction of wind speed and a controlled ventilation is essential for personal comfort. During the periods when natural ventilation is dominant, the air will first enter to environmental zone and inside this zone it will contact with vegetation. This will improve the air quality before it is introduced to the office zone. At the times when the wind flow is not sufficient for ventilating the office zone, we are planning to use the stack effect at the southern façade. The windows at the southern façade can be opened only from the top, which allows air to rise up and leave the building, creating a low pressure zone. Then the denser air at the northern region will flow through the low pressure zone, generating an in-floor ventilation. 5 VEGETATION Inside the environmental zone, we designed a vegetated area. This zone is on accordance with our C2C strategy as the earth and plants will be transported back to the environment, to where they actually belong at the end of the building s service time. We are planning to benefit from the vegetation in three ways. First, at the times when the natural ventilation is the dominant ventilation system, vegetation inside the environmental zone will improve the air quality. Secondly, when the user is inside the environmental zone, which will have a very diverse climate, the vegetated area will be on the outer façade side and thus will cover the uncomfortable zone. Last but not least, vegetation inside the environmental zone will be a significant thermal mass and it will be responsible for avoiding the climate in this zone to be at the extremes. 6 WIDENED GLASS SURFACE Our initial goal for this solution was to improve the amount of daylight entering to the office zone. This started with removing opaque materials from the façade and introducing new glazing material as a replacement. Therefore the renovated façade is composed of transparent materials and thus, the amount of daylight entering to the building is increased. Another design choice at this stage was to select a material separating the environmental zone with the office zones. In order to keep the improved daylight use, we have decided to use glass exteriors for the office zone. This choice is important for the use of daylight also at the office zones and working spaces. The planned strategy for daylight utilization is in good agreement with the BREAAM-NOR criteria Hea 1 (Daylighting). 7 PERSONALIZED LED ILLUMINATION STRATEGY for the cases when the daylight is disturbing or not sufficient for working, personalized LED system will be used for illumination. The personalized system is important to separate the office zones to multiple zones so that when the natural lighting is sufficient for one side (for instance, south) and insufficient for another, the users will have the freedom to choose which lighting system they want to make use of. With the personal LEDs, we have aimed to reduce energy consumption and also we have tried to give everyone the freedom to choose what kind of lighting they want in their workspaces. This personalized zones is a good adaptation strategy for the BREAAM-NOR criteria Hea 6 (lighting zones and control). 8 MALL Mall areas are expanded through the outside of the building, creating a composition of mall areas combined with public plaza that becomes one with the mall circulation spaces. Mall s significance and presence is further strengthened by being a junction where access to offices, access to the central hall of the station and the pedestrian bridge are combined, rendering it a lively public space that contributes to its neighborhood with its dynamism, opening the building to the environment and to the public realm. 9 BIKE FACILITIES Bicycles are the most ideal solution when green mobility is considered. Therefore starting from the outside of the shopping mall, we have placed easily reachable bike parks and bike storages. Moreover, for the comfort of cyclists, close to the indoor bike storage area we have placed showers, changing rooms and drying spaces for wet clothes. These measures are in good agreement with the BREEAM-NOR Tra 3 regulation. For the pedestrian and cyclist safety, sufficient space around the building can be found. However, in order to meet with the Tra 4 regulations of the BREEAM-Nor, further meetings with the Oslo Municipality officials are necessary as the regulations demand strict dimensions and cycle access criteria.

MALL-PLAN P1m / MEZZANINE P1 / GROUND FLOOR P2 / MALL & STATION U2 / BICYCLE PARK

Wınter Ventılatıon Summer Ventılatıon The system works by extracting the indoor air from the southern region and it introduces new fresh air from the ventilation inlets at the northern side. The extracted air, before it is released to outdoor, will be subject to heat exchange (via pipes) with the incoming, fresh but cold air. Therefore the cold air will be heated to a warmer condition before it is utilized by the ventilation system. Thus, the system re-uses the thermal energy consumed earlier. By coupling the extraction and inlet system, the aim is a mild air flow through the office floors. During summer, natural ventilation will be used frequently. In order to bring the outside air to the building interior we planned to implement windows at the north and south facades with different characteristics and to avoid high levels of ventilation, controllable. typical office floor plan

outer shell FACADE Automatized system to control airflow from natural ventilation by operable windows. Environmental zone heated indirectly by the office area. Warm part of the zone is dedicated for circulation whereas the cold part is for plants. Office zone is seperated from the environmental zone through single glazing glass, allowing the environmental zone to be influenced by the climate of the office zone. Glass surface on the facade is expanded for daylight utilization. Vegetation increases the air quality and thermal mass, simoultaneously giving a new presence to the building. By changing the position of one facade cladding element and removing the other, window area has been expanded 0 50 100 200