Sustainable High Rise
September - November 2011
In a group of six students, we developed a High Rise building in the center of London. Each group member fulfilled a different role in the design process. The group consisted of an architect, BIM architect, structural engineer, building services ingineer, facade engineer, and process manager and real estate advisor. As building services and sustainability consultant, my main objective was to create a sustainable building. With this multidisciplinary set-up the needs of all group members were equally important, and therefore the design is not as sustainable as it could have been.
Growing City architectural concept
The high rise complex is located in the city of Westminster, in the city center of London. As London is a growing metropolitan the concept of the GROWING CITY came into being. The configuration of the building blocks expresses a fast growing city. Buildings become higher and higher and even have to be placed on top of each other due to lack of space.
The ground floor public area is created by lifting up de blocks, leaving the ground floor space open. With different facades, the building blocks can really be identified as separate blocks. However, the facades show similarities to unite the buildings.
Cultural attractions and main routes in the area
Building facade directions according to plot lines
Left: the CO2 production during the lifespan of a CO2 neutral building.
Sustainability research goals
Right: the CO2 production during the lifespan of a common building.
Sustainability in buildings is primarily about CO2 emission. By reducing the CO2 emission, the building becomes more environmental friendly. But sustainability is also about creating a building people feel comfortable in. The better the design, the less changes the building
will need to undergo and the longer the building will last.
CO2 emission is both a result of energy consumption in buildings and a result of the production and transportation of building materials and the construction on site. Generally, in buildings the CO2 emission only rises during its lifespan, due to the lack of CO2 absorption (by plants) and energy consumption. In the ideal situation the CO2 emission is minimized during the construction period and the building absorbs CO2 during its lifespan, so when the building is demolished it's fully CO2 neutral. In the design for the Growing City the goal was to stay as close to the ideal situation as possible.
Aims and design solutions for sustainability
To create a sustainable design and thus reduce the CO2 emission, the design was based on 9 aims:
1. reduce footprint by lifting some building blocks. With a reduced footprint more space is left on ground floor level for trees and plants.
2. reduce the amount of materials used and use of materials with less CO2 emission, thus use local materials to reduce transport distance and use of wood because of its negative CO2 emission.
3. natural ventilation has a lower the energy consumption compared to a mechanical ventilation system and improves psychological health.
4. placing trees and plants in and around the building to absorb CO2 during the lifespan of the building and to improve the user's psychological health and productivity.
5. force waste separation onto the buildings' users by separate collection of glass, paper, green waste and other waste on each floor.
6. rain water collection on the building facades and used as grey water in the building.
7. open floorplans will allow the interior to be changed without the need to build new buildings.
8. reducing energy consumption by allowing as much natural light as possible to enter the building, reusing heat in the building by heat exchange between functions, using produced heat in the atria, and use more energy efficient appliances.
9. production of green electricity on the building plot by solar panels and transparent pv cells on the south and west facades of the building.
The 3 sustainability functions of the atria
The atria support the architectural design in the sense of interesting views through the building. But they were also of vital importance to achieve multiple of the 9 sustainability goals.
1. The building allows for natural ventilation with stack effect occuring in the atria. The stack effect of the atria will suck the air from the sourrounding rooms into the atria. As a result, the rooms will take in fresh air into the building through the facade.
2. The stack effect occurs because hot air rises in the atria. The temperature will rise towards the top of each atrium. The building exploits this effect: at the top of the atrium the heat is extracted and used to heat the rooms in the building.
3. Natural light enters the atria by the use of heliostats positioned on the roof, to provide the building with as much natural light as possible.
9th floor: offices and low end residences
The design decisions for sustainability are visible in the wooden flooring in the offices and residences. The atria in the office space and in the hallway towards the residences guide daylight into the space and provide space for trees at ground floor level.
20th floor: transfer floor
The transfer floor is a public floor level. It contains an exhibition space, fitness, spa, eating facilities and a nice view of the city. The floors are made of wood, and the space is filled with trees and green walls. The atria provide the large space with natural light.
45th floor: high end residences
The most expensive residences are on the higher floors. Each floor contains two apartments. Each apartment has a view of it's 'own' atria, which feels like a small green patio in the middle of the apartment.
How sustainable is this high rise building? How much does the design approach a CO2 neutral building? Here a few of the conclusions of this project:
- Rough calculations conclude that the solar panels and solar cells annualy produce more electricity than necessary, so users of the buildings only consume green electricity. This is partly possible due to reduction of the energy consumption for heating and cooling.
- Trees and plants and vertical vegetation attached to the walls in the atria allow for nice views in the building. This part of the design is both a sustainable and an architectural design solution.
- Generally, about sixty percent of energy used by residences and offices is to heat and cool the buildings. Using a system of heat exchange between cooled and heated functions reduces that energy consumption by 89%.
- The amount of rainwater collected on the facades only covers about 10% of the water consumption in the buildings. Reuse of grey water is therefore important.
- Rough calculations conclude that the building will be completely CO2 neutral in case it has a lifespan of over 400 years. CO2 is absorbed during the lifespan of the building by the vegetation and (theoretically) by production of green electricity.
1. reduced footprint by lifting building blocks. 2. heat is exchanged between functions that generally require cooling (blue) and functions that generally require heating (red). 3. greenery in and around the building. 4. natural light enters the building through the atria. 5. the hot air in the atria is extracted to heat up the building. 6. natural ventilation through the facade and the atria.
Transfer floor: the large atrium guides natural light into the space from the top, and provides nice views of the floors above the atrium.
High end apartment: the atrium on the left side guides natural light into the apartment and provides a nice view on plants attached to the atrium wall.
See more of my research and projects on sustainability:
© Copyright Lara Tomholt 2015