This article aims to be the first of its kind to assess the sustainability of Hobbit holes as it is becoming increasingly important to find new and sustainable living alternatives.
The Hobbits’ ‘down to (middle) earth’ approach to housing is characterized by organic shapes and the fact, that they are typically located underground on hillsides. Materials used are wood, brick, stone, grass and sod.[1] When evaluating their sustainability, wood is a renewable resource, which can act as a carbon sink and requires less energy to produce than other materials. The Hobbit population is comparatively small, but should it grow significantly, deforestation could become a problem and the biodiversity might be affected.[2] Stoneware excels as a building material through its durability and ease of handling with almost no negative side effects. Bricks, like stone, are very durable and have good thermal mass properties, resulting in better control of indoor temperature and therefore lower energy consumption.[3] The grass that grows over the Hobbit holes can photosynthesise and therefore act as a carbon sink.[4] In addition, it should be noted that the digging process itself can release greenhouse gasses bound to the soil. However, this is an almost negligible amount.[5]
Thermodynamically, the earth can act as an insulator against freezing winter air, but only up to the point where the air temperature in the Hobbit hole reaches the temperature of the surrounding earth. Thereby, the energy which is required for heating might depend on the region, where the Hobbit hole is built. As the weather in the Shire is described as mild and temperate with hot summers and cold winters, it is similar to the English countryside. That means that temperatures might range from -26 °C to 40 °C with the ground temperature being up to 8°C lower than the air temperature.[6] [7] To calculate the energy that would be necessary to heat such a space, the heating degree days, the shape form, base temperature, heat output of the wood stove and hours of use per year have to be determined. As Hobbit holes are underground the outer area is comparably small and the shape form was assigned a small value of 0.5. As no architectural measurements are known about this type of housing this value is merely an educated guess. Data from England was used for the estimation of heating degree days (summations of negative differences between the mean daily temperature and a 15.5 °C base), which is 2,463 °C days.[8] The other values needed, were approximated using reasonable values for the heat output (21 MJ*h-1) and hours of use ( 1232 h) for a wood stove resulting in a required heating energy of 26,026 MJ*yr−1, which is similar to a single-family home. However, it is worth mentioning that wood split logs as a feedstock involve a higher emission of gaseous pollutants per MJ than other alternatives like, for example, a pellet stove, which has a higher energy conversion efficiency.[9]
When thinking about sustainability, it is important to note, that several Hobbit generations live in one Hobbit hole.[10]
This decreases the demand for area, that is needed for housing and results in less usage of resources compared to single-family homes. It is also important to note that Hobbit houses play a vital role in their community and part of the sustainable building mission is to preserve culture, as this promotes a sense of community and appreciation among the population. Through the level design of the Hobbit’s house, which is an inclusive architectural feature, both older generations and physically challenged groups can be accommodated.[11]
In conclusion, it can be said, that Hobbit holes are a simple, sustainable living alternative. However, only the feedstocks, required heating energy and social aspects were taken into account. Other aspects like water, location, affordability and durability were beyond the scope of this article and are content for further research.
[1] Tolkien, J. R. R. (1991). Der Herr der Ringe. http://ci.nii.ac.jp/ncid/BA23541284
[2] Forestry, Wood and Paper products sector information. (2024). United States Environmental Protection Agency. https://www.epa.gov
[3] Home – the official International Brick Collectors Association. (2019, 11. August). The Official International Brick Collectors Association. https://www.internationalbrickcollectorsassociation.com/
[4] Forage and Turf Grass Research: USDA ARS. (o.D.). https://www.ars.usda.gov
[5] Rodríguez-Montañés, R. \& Pérez, F. R. (2021). Carbon foot print evaluation in tunneling construction using conventional methods. Tunnelling And Underground Space Technology, 108, 103704. https://doi.org/10.1016/j.tust.2020.103704
[6] UK climate extremes. Met Office. https://www.metoffice.gov.uk/research/climate/maps-and-data/uk-climate-extremes
[7] Deutscher Wetterdienst – Frostgefährdung. https://www.dwd.de/DE/fachnutzer/landwirtschaft/dokumentationen/allgemein/frostgefaehrdung\_doku.html
[8] UK standard degree days. (o.D.). https://vesma.com/ddd/std-year.htm
[9] Martín-Gamboa, M., et al. (2019). Multi-Criteria and Life Cycle Assessment of Wood-Based Bioenergy Alternatives for Residential Heating, 12(22), 4391. https://doi.org/10.3390/en12224391
[10] Tolkien, J. R. R. (1991). Der Herr der Ringe. http://ci.nii.ac.jp/ncid/BA23541284
[11] A Handbook of Sustainable Housing Practices in Developing Countries | UN-Habitat. https://unhabitat.org/going-green-a-handbook-of-sustainable-housing-practices-in-developing-countries
