We all know that sustainability is one of the biggest topics to be discussed and developed throughout many different industries. Although the AEC industry contributes up to 40% of the carbon emissions responsible for climate change, there is also an amazing opportunity to rethink and redesign the way we build.
That is why, a while back, I have completed a course on Sustainable Building Design hosted by MITx on the EDX platform. I wanted to learn more.
The goals of this course were very straightforward, which should be reflected in my final project.
- understand and apply the scientific principles underlying the thermal and luminous behaviour of buildings,
- learn to evaluate the pros and cons of a range of technologies for creating comfortable indoor environments,
- conduct a series of design analysis workflows regarding climate, building energy use and daylighting,
- acquire the knowledge required to critically discuss/present the environmental concept of a building.
If you are curious about the course, or you want to follow along and share your insight or feedback, you can have a look at my final presentation below.
The presentation
The design philosophy is based on Nordic architecture with a strong sustainable profile. The focus of our design is the duality between open and closed spaces — which is also prevalent in the location of our choice — Ørestad. The Business District Ørestad lies across from new residential neighbourhood, creating both public and private spaces. One of the main features of this neighbourhood is the presence of large windows so that the office building take advantage of the daylight.
Two of the most well know offices in Øretad are Sweco headquarters that has achieved a gold DGBN prequalification, and the new Nordea headquarters with a platinum LEED certificate.
Energy Utilization Index (EUI)
Given that the Ørestad neighbourhood is fairly new, with the first office building completed in 2001, it is expected that the buildings are built to the latest standard with clear sustainability goals.
Based on the Danish Building Regulations (BR18), the target site EUI for an office building is 41,4 kWh/m2, which is below the minimum according to The Building Performance Database website. It is important to note that The Building Performance Database website takes its data from US buildings, while the Start-Up Space is located in Copenhagen, Denmark.
The settings for the database are set to reflect as close as possible the conditions in Copenhagen.
Climate analysis
The location of the Start-Up Space is set in the southern part of Copenhagen, Denmark, which is a temperate oceanic climate (Cfb according to Köppen climate classification). With the coldest month averaging above 0 °C (32 °F) (or −3 °C (27 °F)) and 1–3 months averaging above 10 °C (50 °F) — also as shown in the ClimaPlus outdoor temperature graph.
Copenhagen, and Ørestad, in particular, is fairly well connected to the city, averaging a good walking score according to Walkscore. It is in the heart of The Business District Ørestad and it is connected to the city through a metro line. It also has bike lanes that encourage the locals to bike — which takes approx 20 min to get to the city centre.
As shown before, the climate in Denmark is temperate oceanic, which means mild weather but high humidity. There is also a fair amount of wind, which is also accentuated by the corridor-shaped boulevard as well as the grid system of the neighbourhood. This means that the building has to particularly airtight, with a good envelope. Due to Denmark being fairly up north in Europe, the days are quite long during the summer and very short during winter. This suggests that the buildings can have large windows that allow daylight during the cold season, while a good shading system helps during the summer.
Site analysis — Location
The location is in the southern part of Copenhagen, on the island named Amager. In terms of surrounding buildings, many of them are newly built. Today, there is a good mix of both residential and commercial buildings, no higher than 13 floors due to strict local urban regulations. There is also a nature park right next to Ørestad which increases the appeal of the neighbourhood.
Site analysis — shading study
The sun shading study is made using SketchUp and it shows the shadows for the two solstices and two equinoxes at noon. The models show the closest structures that potentially affect the building. Because of the low height of the surrounding buildings, there is minimal shading on the building, except for December. This further shows the need for appropriate sized windows.
Building massing
Based on the shading study, we can also see the importance of building shape and its placement. The three possible massing models show a two-floor classic rectangular shape, a two-floor building with an atrium (a very common solution in Denmark), and an asymmetric L shaped building with 2 and 3 floors.
Daylight availability
To be able to further decide which option to choose, we did a daylight availability calculation. The first option is the typical “box” shaped building and it shows that the daylit area is only 66% of the total floor area which is below what we want. The second option is the two-floor building with an atrium.
Without taking the atrium into account, the daylit area is less than the first option. The third option proves to be the best with up to 90% of the floor area being daylit.
The width of the daylit area is 2.5 x wind head height = 2.5 x 2.6m = 6,5m
Visual comfort
Because of such a high percentage of daylight availability, visual comfort is highly important and is emphasized by the Danish Working Environment Authority. It is important to be mentioned that the height of a floor is 3.5m, with a window height of 1.7m. From here we made glare analysis for a person on the south façade of the bottom floor of our building — as shown on the highlighted plan.
Requirements for lighting
- As a general rule, there must be a view of the surroundings from workspaces through windows or the like.
- The light must not dazzle, cause annoying reflections or annoying heat.
- Both general lighting and spotlighting must be flicker-free.
- Windows must have a screen that can dim bright daylight that falls on the screen workplace.
- Light sources must be cleaned and maintained, otherwise, they do not provide optimal light.
Avoid annoying reflections on the screen
Position the monitor to avoid annoying glare. This can be done by placing the screen on the side with the light incidence. At the same time, the screen surface and edges should be matte so that they do not reflect light.
Glare can be reduced by:
- Use of bright colours in the room.
- Use of screened fixtures that also illuminate the ceiling.
- Avoid placing luminaries immediately above or in front of the workplace.
To calculate the visual comfort, we used both ClimaPlus and Andre Marsh’s sun path app. We made glare analysis for a person on the south façade of the bottom floor of our building. From the analysis, we can see that there is a great chance for the glare in the wintertime and most of the spring and autumn days. This supports our hypothesis that there will be a need for shading because of glare.
- March: In March, the sun is visible between 6:00–10:15 and between 14:15–18:30 pm local time.
- June: The sun is visible between 4:30–7:25 and between 17:00–22:00 local time.
- September: The sun is visible between 7:00–9:55 and 14:05–19:00 local time.
- December: The sun is visible between 8:30 and 15:30 local time.
Electric lighting — option 1
The lighting options were decided using the DIALux mobile app. The first option is a Regiolux recessed luminary and the calculation was done for only a part of the building. From this, we can extract a specific lighting power density of 6.65 W/m2, which would amount to 6.65W/m2*2500m2 = 16,625 W for our building.
Electric lighting — option 2
The second option is a Fagerhult recessed luminary and the calculation was done for the same part of the building as before. From this, we can extract a specific lighting power density of 5.44 W/m2, which would amount to 5.44 W/m2*2500m2 = 13,600 W for our building. The difference is clear in power consumption as the second option is more power-efficient.
EUI study — Base Condition
The base condition of the building is set to the standard regulatory requirements and we can see that it is lower than the average EUI, but does not comply with our target EUI. The heating is also set up for ground source heat pump as the heating in Denmark is mainly through district heating.
The Window to Wall Ratio (WWR) is also set to 50%, except for the northern wall as it is connected to the rest of the building. An important aspect of the calculation is that there is no gas used in the energy calculation, as Denmark uses predominantly electricity and district heating.
The price and CO2 emissions for electricity were set based on local key figures.
EUI study — Window change
The first upgrade made was for the windows as they are a key part of the design concept. Optimised windows to double low E and low solar gain windows decreased heating but increased operational costs and emissions.
EUI study — Envelope change
The next change is having a better envelope. The total EUI decreased to 34 kWh/m2. A drastic change for the better can be seen in the heating, as well as in the cost and emissions.
EUI study — Thermal mass
The last upgrade tested is taking advantage of thermal mass. Here we can see a slight increase in heating and as a consequence, an increase in cost and emissions.
EUI study — Comparison
At first glance, it seems that it would have been enough to change the windows and envelope as the second scenario gives the best EUI, which is below our target.
Thermal comfort — cooling
Here we can clearly see that scenario 2 is not enough and that it has more hours with a temperature above 27° than our base. However, even with the thermal mass upgrade, there are still 45 hours with a temperature above 27°. So cooling must be considered.
Thermal comfort — Best choice
Finally, the best choice includes all upgrades and cooling for optimal energy use. As we can see the final EUI is 38 and below our target. This has been achieved through simple steps and rules of thumb applied to a simple design. The result is satisfying and we hope that it will create a great environment for future start-ups.
Finally, thank you for reading this article! 😁
If you want to get in contact with me, you can find me on LinkedIn, Twitter, and of course on my personal website.
