In 'depth': living underground

Imagine opening your eyes to the smell of gravel and sand. You know it’s the morning but your room is in complete darkness. Your hand feels around for the button conveniently located at the side of your bed. The light flicks on. You wince at the sudden assault of light rays from the bulb. Your head instinctively turns to the window where the trees would be swaying in the morning breeze, cars would be zooming by and housewives would be scuttling to the market, giving a vivacious review of last night’s drama. But then to your horror, you are reminded of the fact that you don’t even have a window.

This is probably a scenario which we would associate with living underground. After all, we are moving below the surface, covered by layers of silt and soil, far away from surface life. We think about the animals adapted to living underground such as the naked mole rat. Aren’t they a bunch of odd-looking creatures? Would we turn out like them if we live underground for too long? Apart from the fear of storing explosive or toxic chemicals in underground caverns, people are distressed over the potential health complications of long-term residence underground (Evans et al., 2009). Claustrophobia may be possible, since there is no stimulus from the outside environment. Living below ground also means that we won’t get our daily dose of sunlight and the calcium retaining vitamin D that comes with it. According to Michael J. Breus, diplomate of the American Board of Sleep Medicine, natural light helps reset our internal biological clock every day which in turn affects our mood, metabolism, body temperature and immune system. We need to see and feel sunlight to be able to have some form of a sleep pattern. Ventilation is also a concern as we need to make our underground homes feel less like a stale prison cell. What about green spaces? We certainly cannot live with just looking at concrete every day. Thankfully, there are solutions to all these worries with technological advancements which could minimise the difference between underground residences and those on the surface.

Sadly, there are barely any studies done on the psychological impacts of living underground. But with today’s people already working and studying in windowless environments, or have their blinds down and windows blackened out, they probably would have no problem adjusting to life underground. A study on the attitudes and satisfactions of earth-sheltered housing to a group of people in Minneapolis-St Paul, Minnesota found that the earth-sheltered residence was generally desirable. Their attitudes towards underground living improved after they had lived in the houses (Bartz, 1986). However, 50% of townhouse residents in the survey felt like escaping from their house, and 21% of the single-family group had the same feeling. Their reasons include not wanting to finish the house and household chores (I’d run out of my house anytime if I have household chores to do).

Most important is the impact on the environment when we excavate the ground. Evans et al. (2009) pointed out that if not done properly, underground development could result in damage to the constructions above ground, exposing overhanging pieces of land, stopping groundwater flows, causing wells to dry up or allowing seepage of pollutants that lower groundwater quality. By moving underground, we may also be competing with the animals that have long exploited the underground space as their habitat.

With the tightening squeeze we are facing on our lands, living underground may not even be up to our choice. It’s either that or an underwater city, right? And let’s not go into the sensibility and practicality of that.

Literature cited:

Bartz, J., 1986. Post-Occupancy Evaluation of Residents of Single- and Multi-Family Earth Sheltered Housing. Tunnelling and Underground Space Technology, 1(1): 71-88

Breus, M. J., 2010. The effect of circadian rhythms on the sleep cycle. Sleep Newzzz, 11 November 2010. URL: http://www.psychologytoday.com/blog/sleepnewzzz/201011/underground-and-out-sight. Last accessed 20 September 2014.

Evans, D., M. Stephenson, & R. Shaw, 2009. The present and future use of ‘land’ below ground. Land Use Policy, 26: 302-316

Build it like the termites

Termites are often called the architects of the insect world. Standing at a whooping height of 7.5m (Anitei, 2007), termite mounds are definitely much more than your average anthill. Who says we can’t make a mountain out of a molehill? What lies inside the mound is a bustling city of tunnels and shafts where the termites store everything from their larvae young to their agriculture (not just food, but agriculture!). The picture below shows the structure inside a termite mound.

(Picture from Nature, n.d.)

A single vent comes down from above the mound and is connected to various tunnels that air from the whole nest can flow into (Nature, n.d.). The warmer air from the nest rises up to be expelled out of the mound while cooler air sinks. This ensures that the air circulating in the nest is maintained at a tolerable temperature. The termite city is actually located underground (number 3 as shown in the picture). There, you can see large networks of tunnels and little ‘rooms’ partitioned by thin walls. These small critters even have a fungal garden where they grow fungus that they consume. The fungus requires a steady temperature to thrive, hence it is crucial that the nest has a stable temperature. How then do the termites enter and leave the nest? There are entrances at the base of the mound (labeled number 4 in the picture). The last part of the mound is the cellar, the bottom-most structure in the mound. The top of the cellar contains a layer of thin plates that absorb moisture from the nest above. Evaporation of this moisture helps to reduce the temperature of the whole nest.

Ingenious, isn’t it?

Perhaps we can learn something from the design of the termite’s mound to create an underground city for ourselves!


Literature Cited:
Anitei, S., 2007. The Largest Natural Buildings. Softpedia, 20 June 2007. URL: http://m.softpedia.com/the-largest-architectonic-buildings-in-nature-57816.html. Last accessed on 13 Sep 2014.
Nature, n.d. The Incredible Termite Mound. Nature, The Animal House. URL: http://www.pbs.org/wnet/nature/episodes/the-animal-house/the-incredible-termite-mound/7222/. Last accessed on 6 Sep 2014.

Green Engineering! (journal review)

Benardos, Athanasiadis and Katsoulakous (2013) discussed the benefits of underground buildings as a modern residence with green engineering. An overview of the benefits of underground constructions were given, such as freeing up surface land and having low visual impact on the landscape The benefits focused on energy savings and they are presented in two ways, namely through a comparison between an underground dwelling and an equivalent surface building and through explaining the Science behind earth insulation properties. Other aspects of comparison included cost of construction, materials used and aesthetics. The journal cited previous studies that all consented with the trend of decreasing heat transfer with increasing depth. It is clear that thermal lagging is more effective with thicker earth cover. The journal then describes the geographic conditions of the experimental site as well as the designs of the underground building. It is important to note that careful details were given on how natural illumination and ventilation were achieved. Data on the heating and cooling demands of the two types of buildings were recorded on a monthly basis. The journal can be summed up to comprise of four key sections: the comparison assessment, living environment, energy usage and cost.


The comparison assessment was conducted at Kea Island, a popular tourist destination. The island already boasts some semi-underground houses, so an underground building would be no shock to the locals. The area receives plenty of sunlight, with warm temperatures, little rainfall and high humidity. The conditions are mostly similar to that of Singapore, which allows for extrapolation of the results. The comparison assessment is a fair one, as the characteristics of the two buildings are kept mostly the same. The thermal insulation used for the aboveground building was much better than stated in relative legal standards. Bernardos et al. (2013) noted some differences in variables, including excavation, building structure and material use, waterproofing and thermal insulation (waterproofing is needed for underground building, but thermal insulation is only needed for the surface building). Underground buildings require ventilation systems and light chimneys but surface buildings need more windows and doors. These were all calculated towards the cost of construction. However, it would be preferable to compare with different depths of buildings and across a wider range of comparison factors like energy consumption, living conditions, air quality and accessibility, since Singapore would likely need to explore the pros and cons of digging deeper. The study in this journal had some comparison of living environment, energy use and cost between the two types of houses. Living environment is the main consideration for any residence, much more since it is below the surface, a very unfamiliar experience to many.

(The interior of the earth-sheltered building used in the study)

Bernardos et al. (2013) acknowledged the problem of claustrophobia from living underground. It can be resolved by having a direct view of the outdoor landscape and a minimum height of at least 2.8m in the building. However, an outdoor view would only be possible if the underground building had some parts exposed. This would pose a difficulty for moving deeper underground and adding many levels. It would not be feasible and practical in Singapore and defeats the primary purpose of mitigating land constraints.


It is argued that underground buildings use up less energy in heating and cooling as compared to surface buildings. The total reduction in energy demand for cooling was greater than that for heating. The EN 13790 methodology was used to estimate energy demands and it was recognized that this method is not able to accurately calculate heat transfer due to heat capacity of the building shell of the aboveground building. This means that the energy demand of the underground house would be theoretically even lower than what was calculated (since the underground building does not have a building shell). Two solutions were even provided for covering heating and cooling loads (oil fired central heating system and central heat pumps). It can therefore be concluded that underground living reduces energy consumption and saves electrical costs. This is useful for considering underground residences in Singapore where air-conditioning takes up the lion’s share of electricity consumption (Energy Market Authority, 2001).

(The total energy demand of the underground and aboveground buildings over the months. Green represents the underground building while orange represents the aboveground building)

Construction costs were shown to favour the surface building. This is expected due to the extra cost for excavation. Bernardos et al. (2013) argued that the total cost for the underground building would be lower than the aboveground in the long run due to less maintenance cost. However, they failed to provide evidence for this claim. Underground structures might need some maintenance and regular quality checks and it is early to state that they would be cheaper than that of surface buildings.


In conclusion, the comparison assessment present in this journal is useful in proving the massive savings in energy from cooling needs. It also shows the possibility of building a livable underground home without negating aesthetics and comfort. However, little was mentioned about the disadvantages of underground buildings, which would better help in assessing the viability of underground buildings in Singapore.




Article reviewed:
Benardos, A., I. Athanasiadis & N. Katsoulakous, 2013. Modern Earth Sheltered Constructions: A Paradigm of Green Engineering. Tunneling and Underground Space Technology, 41: 46-52.