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.