Greenhouses
Indoor food gardens and interior greenhouses have been around for thousands of years. As far back as the Roman Empire, there have been attempts at systems to cultivate plants all year round by monitoring indoor climates and temperatures. Early examples of greenhouses appeared in the 17th century in Europe; in the Palace of Versailles and in Leiden in Holland (ClimaPod, 2024).
In its most simple form, a greenhouse is a metal framed building used for the cultivation and/or protection of plants. Covered in translucent material like glass, plastic or polycarbonate, the internal conditions can be managed to ensure they are the most suitable for growth and development of the plants (Cepeda et al., 2012).
The greenhouse’s structure protects the crops from the elements, while allowing solar radiation in, creating a heat exchange. Adjustment of climate conditions, nutrient cycling and irrigation control can improve the production and increase the yield of crops (Cepeda et al., 2012). Additional methods to improve interior conditions are ventilation, heating systems and shade systems.
As people around the world become more attuned to the climate crisis, there is a growing movement towards sustainable architecture and renewable energy models. The greenhouse has now become a strategy not only for reliable food sources, but for a new, integrated way of living. Greenhouses can now be found in design movements like ‘Earthship’, where they are integrated into residential dwellings, contributing to the heating, cooling and ventilation systems.
The Earthship Model
The Earthship concept was developed by Michael Reynolds, an American architect. It is an autonomous home, constructed sustainably from natural and repurposed materials that can be built by the owner using common tools (Freney, 2012). The home is designed to be passively heated, cooled and ventilated, with self contained sewage treatment and water recycling, as well as internal food production.
The greenhouse can become a key component of an Earthship house, wrapping around the front, drawing in the sun that is then managed through convection. Additionally, the production of food on-site, means the occupants can be completely self-sustainable.
The Earthship concept is growing around the world, and creates possibilities for climate change adaptation, energy decline, resource scarcity and the future of the humble greenhouse, as part of a wider system that creates renewable energy, and net-zero carbon ways of living.
Name of NbS
Indoor (food) gardens/Interior greenhouses
Type of NbS
Combination
Location
Building/single site
Case Study
Earthship Te Timatanga (atrium)
Relationship to Indigenous knowledge
Beliefs of Indigenous people in Oceanic nations hinge on a reciprocal relationship with the land. Nature is the source of all life, the core of culture and intrinsic to identity. It is a source of medicinal and spiritual healing (Dickie, 2005). Growing one’s own food, caring for it as a precious, local resource, and growing it naturally without chemicals is aligned completely with indigenous beliefs and knowledge. A greenhouse can be a source of self-sufficient resource, at a time when resources are scarce.
Beyond a greenhouse’s ability to grow food, they can be a way to conserve and research native and endemic plants – to care for our natural world and find ways to protect them.
- Changes in phenology (changes in plants and animals)
- Loss of food production
- Reduced soil quality
- Wind / storm damage
- soil erosion and landslides
- increased temperatures
- increased pests / weeds
- Flooding
- Drought
- Desertification
- salt water intrusion into aquifers
- changes in rainfall
The annual cycles of plants (phenology) are extremely sensitive to changes in climate and adjust their flowering or production based on the weather and temperatures (Climate Adaptation Science Centers, 2016). The natural world is all connected – plants, pollinators, animals, people are all interacting and influencing each other’s growth. If conditions change, or we experience extreme weather events, our traditional farms and crops are affected. Greenhouses provide a climate controlled alternative to grow and support produce.
As the world’s population grows and our energy consumption increases, there is a need for reliable, healthy produce, grown with renewable energy sources. A greenhouse can grow food by taking advantage of climate conditions – air temperature, humidity, ventilation – and keeping operational energy costs at a minimum (Hassanien et al., 2016). Greenhouses are already being used around the world as a source of managed, mass-produced food production. In Aotearoa New Zealand, more than 90% of the tomatoes, capsicum, and cucumbers commercially grown in Aotearoa New Zealand are grown as covered crops in about 310 hectares of greenhouses, mostly in the North Island (Radio New Zealand, 2024). There are now opportunities to find alternate energy sources – research is currently underway to introduce geothermal energy to greenhouse production.
- disaster risk reduction and resilience
- empowerment / equality
- Food security & quality
- Human physical health and wellbeing
Agriculture is undergoing a shift as the effects of climate change continue to be felt. Climate change and extreme weather makes traditional farming less reliable, and increased demand and post-pandemic supply chain weakness create a clear argument for locally sourced, sustainable produce (Dom & Simos, 2024). Greenhouse production is an opportunity for year-round cultivation, using natural, renewable resources.
Economically, as we experience unpredictable temperatures and water scarcity, the controlled environment of a greenhouse is an economically secure investment. An Earthship home is also economically tactical – any initial costs are offset by the fact that energy bills are significantly reduced, or even eliminated completely, food is produced on site in the greenhouse and so is water.
The controlled environment of a greenhouse, or an Earthship home means that there should be no need for chemicals or pesticides used in traditional farming.
- Food production
- Nutrient cycling
- Biological control (regulation of pests and disease)
- Disturbance prevention
As mentioned above, a greenhouse is a reliable, healthy way to produce food on both local, private home scales, and large commercial scales.
Technical requirements
A simple greenhouse construction is a metal frame with a glass or plastic covering. Various levels of ventilation, shade temperature controls can be introduced. The level of technical expertise can vary depending on size and the requirements of the crops.
The Earthship principles
The six main principles of an Earthship home (Earthship Biotecture, 2024) are:
- Use of natural and recycled materials: Affordable, easily accessible building materials.
- Passive heating and cooling: Thermal Mass, insulation and passive Solar heating/cooling
- Solar and wind energy production
- Food production: A greenhouse attached to the building for year round crop production
- Water harvesting
- Contained sewage treatment
Each of these principles has its own technical requirements. More information about Earthship can be found on the Earthship Biotecture website.
Issues and Barriers
A barrier to the greenhouses is that it requires space. As cities densify, land is increasingly precious and scarce. An apartment complex or housing development might prioritise carpark space over a greenhouse, for example. However, this is part of a wide issue of prioritisation as we build. The value of having an on-site source of produce could be considered more valuable than a car park to some people.
Additionally, managing a greenhouse does require some knowledge of gardening, and the willingness to manage one’s own crops. If there was more education about where to begin, individual households might be more willing to give it a go.
Opportunities
As the climate in Oceania becomes more changeable and unpredictable, greenhouses can be a useful tool in localising produce and ensuring its quality. Greenhouses are simple to make and reasonably cheap to buy, and can be a useful addition to any residential home – private dwellings or in shared spaces in housing developments. They are ideal places to learn and teach about growing and gardening. In cities where large scale, dense housing developments are being built, greenhouses can be incorporated, to create an on-site food source, and a sense of community and connection as people garden together.
On larger scales, greenhouses can house scientific research and management and protection of specific species. For example, in Fiji in 2022, the Centre for Pacific Crops and Trees was opened – a greenhouse facility to support regeneration activities and research. In New Zealand, 80% of our trees, ferns and flowering plants are endemic (Department of Conservation, 2024). Storing and banking seeds, propagating plants and supporting growth are key ways to create a sustainable future for our flora and fauna (Massey University, 2024) – all of which can take place in a greenhouse.
Earthship design is an exciting methodology that can be incorporated into the design of new homes in Oceanic regions.
Financial case
There is a strong financial case for greenhouses, on all scales. In a private home, having a local and healthy source of produce is undeniably cheaper than buying it, especially in the current cost of living crisis. On larger scales, local produce eliminates transport costs and environmental impacts.
Energy is the largest overhead cost in the production of agricultural greenhouse crops in temperate climates (Hassanien et al., 2016), but there is an opportunity to implement solar energy into greenhouses as a renewable alternative.
References
- ClimaPod. (2024). The History of Greenhouses. ClimaPod. https://climapod.com/the-history-of-greenhouses/#:~:text=In%20the%2013th%20century%2C%20greenhouses,mentions%20date%20back%20to%201450
- Climate Adaptation Science Centers. (2016). The Impacts of Climate Change on Phenology: A Synthesis and Path Forward for Adaptive Management in the Pacific Northwest . USGS.
- Department of Conservation. (2024). Native plants. Department of Conservation, Te Papa Atawhai.
- Dickie, R. A. (2005). Indigenous Traditions and Sacred Ecology in the Pacific Islands . Journal of Undergraduate Research, 8. https://www.uwlax.edu/globalassets/offices-services/urc/jur-online/pdf/2005/dickie.pdf
- Dom, I., & Simos, N. (2024). The Case for Investing in Greenhouses in the United States. Agritecture.
- Earthship Biotecture. (2024). About Earthship Biotecture. Earthship Biotecture. https://earthship.com/about/
- Freney, M., Soebarto, V., & Williamson, T. (2013). Earthship monitoring and thermal simulation. Architectural Science Review, 56(3), 208–219. https://doi.org/10.1080/00038628.2013.809688
- Freney, M. (2009). Earthships: sustainable housing alternative. International Journal of Sustainable Design, 1(2), 223. https://doi.org/10.1504/IJSDES.2009.028885
- Hassanien, R. H. E., Li, M., & Dong Lin, W. (2016). Advanced applications of solar energy in agricultural greenhouses. Renewable and Sustainable Energy Reviews, 54, 989–1001. https://doi.org/10.1016/j.rser.2015.10.095
- Massey University. (2024). Plant science research , Rangahau Pūtaiao ā-tipu. Te Kunenga Ki Purehuroa University of New Zealand. https://www.massey.ac.nz/about/colleges-schools-and-institutes/college-of-sciences/our-research/themes-and-research-strengths/plant-science-research/
- Nine to Noon. (2024). GNS scientist wants greenhouse growers to consider geothermal heat. Radio New Zealand.
- Parikh, J., & Shukla, V. (1995). Urbanization, energy use and greenhouse effects in economic development. Global Environmental Change, 5(2), 87–103. https://doi.org/10.1016/0959-3780(95)00015-G
- Smith, C. (2017). Houzz Tour: Earthship Te Timatanga. Houzz. https://www.houzz.co.nz/magazine/houzz-tour-earthship-te-timatanga-stsetivw-vs~83031011
- Visser, M. E., & Both, C. (2005). Shifts in phenology due to global climate change: the need for a yardstick. Proceedings of the Royal Society B: Biological Sciences, 272(1581), 2561–2569. https://doi.org/10.1098/rspb.2005.3356