> For the complete documentation index, see [llms.txt](https://4revs.gitbook.io/handbook/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://4revs.gitbook.io/handbook/chapters/bio-based-materials/global-insights.md). # Global insights Let's delve into the thinking behind what makes a bio-based material sustainable and determine whether a bio-material can replace its non-renewable counterpart (for example clothing made of 100 percent cotton or modal, instead of elastane).\ \ Which are the most impressive bio-based materials currently available, that are both innovative and sustainable? What advantages do they have over conventional materials? In what follows, we will particularly explore two sectors working on researching alternatives to synthetic materials: fashion and construction. ## Green innovation in fashion The fashion industry is one of the most environmentally impactful sectors globally, with implications on every stage of the production process: from the complex supply chain to the choice of materials; the type of treatments applied to garments; and the significant amount of waste. According to the[ UN Environment Programme (UNEP)](https://www.unep.org/news-and-stories/press-release/un-alliance-sustainable-fashion-addresses-damage-fast-fashion), the industry is the second-largest consumer of water (after agriculture) and is responsible for about 10% of global carbon emissions. This is more than all international flights and maritime shipping combined! Let’s unpack this. First, the fashion industry requires about[ 2650 litres](https://www.businessinsider.com/fast-fashion-environmental-impact-pollution-emissions-waste-water-2019-10) of water to produce one cotton shirt and 7570 litres to produce a pair of jeans. According to[ Business Insider](https://www.businessinsider.com/fast-fashion-environmental-impact-pollution-emissions-waste-water-2019-10#fashion-causes-water-pollution-problems-too-textile-dyeing-is-the-worlds-second-largest-polluter-of-water-since-the-water-leftover-from-the-dyeing-process-is-often-dumped-into-ditches-streams-or-rivers-19), textile dyeing is the world’s second-largest polluter of water, since the water leftover from the dyeing process is often dumped into ditches, streams or rivers. There’s more: a[ 2017 report](https://portals.iucn.org/library/node/46622) from the International Union for Conservation of Nature (IUCN) estimated that 35% of all[ microplastics](https://earth.org/are-microplastics-harmful/) in the ocean come from the washing of synthetic textiles like polyester. You might have seen one of the many popular documentaries from the past decade, like “[The true cost](https://www.youtube.com/watch?v=r1zzZlLNcSs\&ab_channel=Moconomy)” (Morgan, 2015), showing the mountains of fashion waste caused by the culture of fast-fashion. The fast fashion model is named as such because it involves the rapid design, production, distribution, and marketing of clothing, enabling retailers to offer large quantities of diverse products, giving consumers more fashion and product diversity at a low cost. Multinational companies in this segment, such as Zara and H\&M, have been able to produce between 12 and 24 collections per year. This overproduction that can't be absorbed by demand contributes to the fact that 85% of all textiles go to landfills each year (more data can be found [here](https://shenglufashion.com/)). Often, however, they do not end up in the same countries that generate this volume of waste. Tragically, in the case of the [waste in Chile’s Atacama desert](https://www.aljazeera.com/gallery/2021/11/8/chiles-desert-dumping-ground-for-fast-fashion-leftovers), the piles of fashion waste are so extensive they can be seen from space! Also, Ghana is one of the world's dumping grounds for used textiles.[ A recent article in The Guardian](https://www.theguardian.com/global-development/2023/jun/05/yvette-yaa-konadu-tetteh-how-ghana-became-fast-fashions-dumping-ground) showed that Ghana imports about 15 million items of secondhand clothing each week, known locally as "obroni wawu" or "dead white man’s” clothes (this name came about because people don’t think that anyone ‘living’ would give away such good clothes, so they must be dead!). In 2021,[ Ghana imported $214m (£171m) of used clothes](https://oec.world/en/profile/hs/used-clothing), making it the world's largest importer. Still, the price paid to Ghanaians is minuscule, only 5 pence per garment. Most of these garments end up in Kantamanto in Accra, the world's largest second-hand clothing market. One hundred tonnes of garments leave the market daily as waste. However, the city cannot handle the waste. About 30% is collected by the city, while the rest ends up in illegal dumps, ditches, and drains. Between 2010 and 2020, 10 legal rubbish dumps in the city were closed after reaching capacity. The situation is unbearable, and Old Fadama, a neighborhood of Accra, is the largest unsanctioned dump for clothing waste, with houses built on layers of rubbish. The coasts of Accra are an endless expanse of dunes made of clothes, not sand. The microplastics that end up in the ocean affect the fish, a crucial protein source for the inhabitants. The country is experiencing a severe ecological crisis that seems unstoppable, partly because the global fashion market is not contracting. In fact, the revenue of the global fashion market is expected to show an [annual growth rate (CAGR 2023-2027) of 9.45%](https://www.statista.com/outlook/dmo/ecommerce/fashion/worldwide), resulting in a projected market volume of US$1,103.00 billion by 2027? The number of users is expected to increase to 3.4 billion users by 2027, says[ Statista](https://www.statista.com/outlook/dmo/ecommerce/fashion/worldwide) in a recent report. Other factors include lax trade and manufacturing laws, and lax environmental regulation in countries outside of western countries. In recent years, however, the sector has become increasingly aware of the issues exacerbating these problems, and there are more and more initiatives attempting to address sustainability. Let's start with some initiatives that use by-products from agricultural supply chains. [**Orange Fiber**](https://orangefiber.it/) **(est. 2014) is an Italian company producing a textile that is 100% a by-product from citrus juice.** The founders saw an opportunity, as every year Italy generates over 700,000 tons of citrus waste, and until a few years ago, there wasn't a viable alternative for disposal (which can be prohibitively expensive). The founders hail from Catania, Sicily, a region known for the production of most of Italy's oranges, linking their origins with their studies of Fashion Design in Milan. They connected the dots and developed an innovative process to extract cellulose from citrus juice by-products, referred to as "pastazzo", made of the residues from orange juice production. They transformed this cellulose into a refined, high-quality fabric. The fabrics are produced from a silk-like cellulose yarn that can blend with other materials. In its purest form, the resulting 100% citrus textile is soft and silky at touch, lightweight, and can be opaque or shiny according to design. The example of Orange Fiber is not unique. A flourishing area of research and development in the fashion industry is focused on finding substitutes for leather made from agricultural waste, in the theme of "vegan leather." The original animal-derived leather raises obvious ethical concerns since it contributes to animal exploitation, with approximately 50 million animals killed each year solely for the leather and fashion industry in general. Moreover, this industry wastes 314 billion litres of water every year,[ with 80% of the animal hide going unused](https://www.innovationintextiles.com/leatherlike-materials-dominate-at-biobased-summit/), primarily due to the hides' asymmetric shapes. What are the alternatives? It is essential to distinguish what is sold as “vegan/eco leather”, a material that looks like leather but is synthetically produced from oil-based materials (composed of synthetic fibers such as polyester coated with one or more layers of polymer, most often polyamide and to a lesser extent pcv), from leather made from bio-based materials, like the ones we are discussing in this chapter. Each product and case requires a thorough life cycle analysis, but it can be said that for synthetic leathers, the environmental impact is undoubtedly higher. [**Desserto**](https://desserto.com.mx/home) **is a Mexican company specialized in manufacturing cruelty-free, biodegradable leather made with Nopal cactus.** They grow the cactus in the state of Zacatecas and select only mature leaves, which can be harvested again every 6-8 months. After cutting the cactus, they sun-dry them for three days until achieving the required moisture level to produce plant-based leather. Desserto also patented an organic formula to bind it together. Compared to animal-derived leather, where one cow consumes on average 6813 litres of water, cacti only rely on rainwater. Cactus is a low-maintenance plant, surviving for months in the wild without any water. Additionally, cactus absorbs CO2 and acts as a natural carbon sink with significant CO2 sequestration capacity. From the 5,6 hectares of cactus at the Desserto ranch, they can absorb 8,100 tons of CO2 per year, while the entire farm only generates 15.30 tons of CO2 annually. Another example of leather derived from agricultural waste is **Piñatex, a vegan leather alternative to real animal leather.** The name Piñatex comes from the Spanish word for pineapple, which is the source of this material, produced from the leaves of the pineapple plant. The pineapple industry generates approximately 40,000 tons of leaves every year, which are typically considered waste and left to rot or burn. Its large-scale cultivation is not exempt from many[ dark sides:](https://qcostarica.com/dark-truths-about-the-pesticide-fuelled-pineapple-industry-in-costa-rica/) primarily soil pollution, intoxication of animals and farm workers, and allegations of illegal deforestation. Piñatex reclaims these leaves to create cruelty-free leather. By using around 480 leaves, equivalent to 16 pineapple plants, the manufacturer,[ Ananas Anam](https://www.ananas-anam.com/), produces 1 square meter of cruelty-free leather. In the production phase, there's no material waste, and the residual biomass from the process is used as fertilizer for local soils. Research and development into bio-based alternatives for leather products are exploring agricultural waste from various supply chains in different parts of the world (grapes, apples, sugar cane, etc.), creating a process of raw material recovery, reintegration into production cycles, waste elimination, and cross-fertilization between industries, resulting in numerous advantages. **An example that addresses the issues arising from animal leather production is**[ **VitroLabs**](https://www.vitrolabsinc.com/)**.** Using the same principle that initiated the production of “lab-grown meat”, this company creates animal leather products without the exploitation and killing of animals. With a single, harmless biopsy from a cow, they replicate in their lab the natural conditions that allow skin cells to regenerate indefinitely and produce billions of square feet of leather. Using a specialized bioreactor, they provide the necessary signals and nutrients for the cells to grow into an animal hide. Instead of taking years to grow an animal, VitroLabs’ process takes just three to four weeks. Obviously, for this type of production, it must be taken into consideration that the technology behind the possibility of developing this "cultured leather" is not accessible in every part of the world, due to economic issues and the tightness of the power grid. Not only that, an industry that requires a massive amount of energy can cause other primary services to lack it and, if fossil-fueled, exacerbate air pollution. Therefore, the scalability of such an operation depends on the contingencies of each individual place. VitroLabs' example is interesting to discover, but several controversial aspects make it less preferable than solutions that are more accessible to more people, circular, and environmentally friendly. The last case study concerning bio-based materials in fashion is slightly different. **Spinnova takes cellulose and turns it into textile fiber without using any harmful chemicals.** Their cellulose-based fiber transforms FSC and/or PEFC certified wood and/or cellulosic waste streams (such as wheat or barley straw) into textile fibers, with only water as a byproduct. They have developed and patented a machine to refine raw pulp into spinning-ready fiber suspension using only mechanical strength. The resulting fiber is ready to be used in virtually any type of textile products. The closed process involves zero harmful chemicals, generates zero waste, and produces only water, which can be used in the spinning process. Spinnova's fiber can replace cotton, viscose, and other raw materials in both woven and nonwoven applications. According to the company, the Spinnova value chain results in 99% less water and 65% fewer CO2 emissions than the cotton value chain. Their fiber is also rapidly biodegradable and recyclable within their process again and again. They claim to be the only company in the world capable of converting cellulose into textile fiber this sustainably and call their method "disruptively circular." Indeed, this example has the potential to radically transform global textile production, making it infinitely more sustainable. Of course, it would be necessary for the technology to be accessible to as many people as possible for the process to scale up. Additionally, it is important to keep an eye on the primary or secondary raw materials from which these yarns are produced. When looking at the data from a more critical perspective, some downsides can be found: Spinnova declares that their "main goal is to industrially scale our technology up to big volumes, for all consumers alike to use." Partnerships with the world's largest wood pulp producer, Brazilian Suzano, and substantial fashion companies like H\&M align with that goal. However, both Suzano and H\&M are accused of various environmental issues. [NGOs claim that Suzano appears to exploit lands and workers in Northern Brazil by planting eucalyptus monoculture](https://www.wrm.org.uy/action-alerts/open-letter-to-hsbc-about-suzano-in-brazil), which has displaced traditional populations, caused land conflicts, and cleared large areas of forest. H\&M, despite its commitment to sustainability and the circular economy, still produces around 12-16 micro-collections per year and remains one of the biggest fast fashion companies in the world, contributing to overconsumption. As most of the pollution from fashion manufacturing is going to South Asia, how can people in these regions benefit from bio-based innovations that are not coupled with fast-fashion? ## Green innovation in construction According to[ a recent article about biomaterials in the construction sector](https://link.springer.com/article/10.1007/s40243-023-00234-7#ref-CR1), "the building sector, one of the most energy-intensive sectors, accounts for about one third of global primary energy demand, which represents a major source of energy-related greenhouse gas (GHG) emissions.” The article reported further facts: * The[ United Nations Global Status Report 2018](http://www.unenvironment.org/resources/report/global-status-report-2018) estimates that building construction and operation accounted for 36% of global final energy consumption and nearly 39% of energy-related carbon dioxide (CO2) emissions in 2017. * If current trends continue,[ buildings will be the world's largest energy users by 2025](https://doi.org/10.1016/j.enbuild.2014.07.032), consuming more energy than the transportation and manufacturing sectors combined. * The building industry uses a significant number of raw materials and consumes a lot of resources.[ ](https://doi.org/10.1016/j.buildenv.2010.12.002)Also,[ the manufacturing of construction materials accounts for more than 80% of the energy consumption of building construction](https://doi.org/10.1016/j.enpol.2019.110949). These are just some of the most significant data that illustrate the substantial environmental impact of the construction sector. Therefore, decarbonizing constructions is crucial for the future to come, and bio-based materials offer promising alternative solutions for our houses and offices. Among the case studies we have examined in recent years, we met companies that have partnered with local industries using surplus and waste from agriculture and pastoralism to make building materials, cements that use hemp or rice as a base, and examples of bio-fabrication from mycelium, the vegetative part of fungus. Each of these multiple realities addresses the need to reduce the impact of the construction industry through the use of bio-based materials, and in this section we will look at some of them. \ \ **There is an Italian company that combines construction with an unlikely industry: local agriculture.** "[EDIZERO – Architecture for Peace](https://www.edizero.com/#top)" was founded in 2006 in Sardinia, an island in Italy with a local economy closely tied to agriculture and livestock farming. The founder's goal was to establish a company that creates zero-impact products for the construction and architecture sector, creating reuse supply chains with what was considered surplus or waste in other sectors, all sourced locally. The EDIZERO ingredients are recovered from agro-industry and food supply chains: sheep and vegetable wool, recycled fibers, cork, hemp, straw, aggregates, lime, surplus from mowing and pruning, inedible plant parts production scraps, all which would otherwise become waste. EDIZERO has created 120 different products, ranging from: energy and acoustic insulation panels, paints, skim coatings, finishes, mortars, adhesives, coatings, geo-textiles, agro-textiles. EDIZERO products have excellent economic sustainability and competitive prices on the market, even when compared to synthetic ones (which are polluting and energy-consuming). This is possible thanks to a visionary effort by all participants in EDIZERO supply chains, who share knowledge, time, and mutual help in order to build a true "architecture for peace". EDIZERO creates cross-fertilization with industries from other sectors to manufacture products that help eliminate ocean petroleum pollution. At the end of their life cycle, the products become either fertile soil or reusable, non-toxic materials. EDIZERO (which can be translated as "Zero Construction") presents itself as a company with many “zeros”:
Zero chemicals or toxic substancesZero mineral fibersZero energy- consuming processesZero exploitation
carcinogens, radon, pesticides and residues,CO2, NOx, SO2, PCP, PCB, PAH, ketones, aldehydes (including formaldehyde), endocrine disruptors, acrylic, alkyd petrochemical, and polyurethane resinsno glass wool, rock wool, basalt, and/or asbestosthermal and/ or thermo-fixing processes

zero use of raw materials causing wars;

no exploitation of oil, landscapes, water, and gas;

no land and ocean grabbing;
no use of water in production or added to the product;
zero discriminatory advertising

### **Hemp-based bricks and insulation panels** **These are some of the products produced by Edizero. Let’s delve deeper into the technology behind them, as it is used by many companies globally, like** [**Hampvaruhuset**](https://www.hampvaruhuset.se/) **in Sweden,** [**UK Hempcrete**](https://www.ukhempcrete.com/)**,** [**Hempitecture**](https://www.hempitecture.com/) **in US, and** [**IsoHemp**](https://www.isohemp.com/en) **in Belgium, just to name a few.** This is a widely adopted technology with historical sources dating its use to different parts of the world, including Japan, China, and Egypt since the time of the pharaohs. It is not a proprietary technology but rather an ancient method rediscovered in the 1980s, which has seen a resurgence after the relaxation of restrictions on hemp cultivation in various countries. Known by various names such as Hempcrete, Hemplime, Canobiote, Canosmose, Isochanvre, and IsoHemp, it offers many advantages and application possibilities. Made of a mixture of hemp pulp/hurd, a lime binder, and water, hempcrete is a simple yet excellent insulating building material. The reaction between lime and water acts as a binder that glues the particles together (bonded cellulose). Unlike other construction composites like concrete, the binder is not intended to fill in all the voids but to merely coat the hemp so that the particles adhere to one another. The resultant product, hempcrete, is a bio-fiber insulation with relatively low density, good insulating properties, and superior resistance to moisture, pests, and rot. While hempcrete is not designed as a load-bearing material, it is best used as wall infill and for insulating around windows, floors, and roofs. However, it has both body and integrity that allow it to be formed into bricks and blocks with some structural properties, though limited. Compared to other insulating materials, the increased density structure and rigidity of hempcrete help in structural reinforcement. Hemp can be grown from seeds in as little as four months and requires few resources for harvesting, unlike its timber counterpart, which takes decades to regenerate and significant resources for extraction. Hemp can thrive in a range of climates and elevations and is known to remediate even the poorest quality soils during growth;does not require herbicides or pesticides; and[ requires very little water and a limited amount of land to grow](https://mediamanager.sei.org/documents/Publications/SEI-Report-EcologicalFootprintAndWaterAnalysisOfCottonHempAndPolyester-2005.pdf). Similar to other photosynthetic plants, hemp absorbs, retains, and converts atmospheric carbon, but it is nearly four times more effective at sequestering carbon than trees: one hectare of hemp can absorb up to 22 tons of carbon dioxide. Every part of the hemp plant can be utilized in various ways. The fibrous part on the outside (the bast) is used for textiles, while the inner, woody part (the hurd) is used in construction, such as for hempcrete. From the seeds, oils can be extracted for agri-food production, cosmetics, or biofuels. Other agricultural bi-products that are also used to produce insulation panels include rice and wheat. Rice production waste is often either burned in fields (producing particulate matter and nitrogen oxides) or put on the land to fertilize the soil. However, if the field is flooded again, the buried straw ferments and produces methane (\* The Fukuoka method composts the stalk on the land but doesn’t flood the fields). Residues from the harvest: the straw, the hull (the shell of the rice grain), and the bran (its discarded coating after whitening) – are rich in extractable or usable components following processing, which are valuable in various industries. For instance, the vegetable oil from rice bran can be used to extract sterol acid esters with anti-cholesterol properties and can replace synthetic sunscreens in cosmetics. Similarly, monodiglycerides can serve as emulsifiers and replace trans fatty acids found in many processed foods (often of animal origin), in cosmetics and pharmaceuticals. Rice hulls have mainly been used as animal bedding or for insulating pipes due to their high absorbency, but now there is a study on the possibility of grinding them and introducing them into composite materials – including plastics – used for exterior and anti-slip flooring. Silica extracted from rice hulls can also be used to create new composites with traditional plastics and bio-based plastics. Finally, straw has insulating properties similar to those of hemp and is suitable for the production of panels used in earthquake-resistant construction (like the “ricecrete” and other products made by [Rice House](https://www.ricehouse.it/en/)). ### Are hemp and rice equivalent? Not necessarily. In fact, they have significant differences. We know that rice is one of the most widely grown grains in the world and a staple food for millions of people. However, the environmental impact of its cultivation, in most cases, is substantial. According to the[ Environmental Defense Fund](https://www.edf.org/media/nitrous-oxide-emissions-rice-farms-are-cause-concern-global-climate) (EDF) in the United States, global rice production releases a significant amount of greenhouse gasses into the atmosphere, causing as much harm as 1,200 average-sized coal power stations. Furthermore, according to the[ Food Systems, Land Use and Restoration](https://www.folur.org/rice) (FOLUR) Impact Program, "rice uses vast amounts of water, degrades soil and water quality, accelerating climate change and ecosystem degradation. Agricultural expansion and monocultures have led to deforestation and land degradation, with negative consequences for wildlife habitats and biodiversity. In some areas, peatlands and wetlands have been drained for rice, and the risks are amplified." While there are some cultivation techniques that could make rice production less impactful, they are not yet the majority (see Soil Secrets for some examples). We must ask ourselves: if we want to use agricultural waste to create insulation panels, which material should we choose? There is no one-size-fits-all answer. For example, if we have a thriving rice industry in our area, it's good to use the waste from rice production in other industries like construction to prevent it from becoming waste that needs to be managed. On the other hand, if we choose to invest in waste from intensively cultivated and environmentally impactful rice, we are essentially funding a highly polluting industry. Of course, rice production for food purposes can be reduced or modified in a short time, but in this case, a choice we can make is to engage with the producers we are interested in and encourage them to redesign their production techniques to make them more sustainable in exchange for taking care of their waste - win win! ### Biofabrication and fungal based construction Architecture and construction don't solely rely on waste from other industries to make their production processes more sustainable. In fact, **using living materials has gained significant attention due to its potential to revolutionize the way we build. In this case, we're talking about biofabrication.** This term doesn't simply allude to materials of "biological" origin. Biofabrication involves controlling the growth of these natural materials in a way that they take on specific, finished forms and characteristics they don't necessarily possess naturally. By manipulating how these basic "building blocks" grow, it's possible to obtain finished products that can replace traditional, environmentally impactful materials. Living materials leverage living organisms' inherent properties and abilities to create resilient, adaptive, and biocompatible structures. Biofabrication involves controlling the growth of these natural materials in a way that they take on specific, finished forms and characteristics they don't necessarily possess naturally. By manipulating how these basic "building blocks" grow, it's possible to obtain finished products that can replace traditional, environmentally impactful materials. For instance, fungi-based constructions offer unique advantages such as sustainability, versatility, and regenerative potential, making them an intriguing avenue for innovative architectural solutions. Fungi have the ability to grow and self-assemble, forming complex networks of filaments called mycelium (the vegetative part of a fungus), and hyphae (its network of fine, thread-like structures) which as a holistic system make up a vast network, or “mycelial network.” The mycelial network is the foundation for fungal-based constructions, imparting structural integrity and material adaptability; it can also respond to changes in temperature and humidity, and other conditions, allowing it to potentially self-repair structural damage. The production of fungal-based constructions involves several stages. 1\. Start with designing and preparing a suitable substrate that provides the necessary nutrients for fungal growth. The substrate can range from agricultural waste, such as straw and wood chips, to synthetic materials. 2\. Once the substrate is inoculated with fungal spores or mycelium, optimal growth conditions, including temperature and humidity, are maintained to promote mycelial expansion. 3\. Shaping and forming techniques, such as molding or 3D printing, can be employed to achieve desired structures. 4\. Post-processing steps may include drying, heat treatment, or surface modifications to enhance the material's properties. The resulting material is lightweight, strong, and biodegradable, making it an eco-friendly alternative to materials like concrete (construction), and plastic or foam (packaging). Fungal growth is fueled by organic waste materials such as agricultural byproducts, reducing the reliance on non-renewable resources or resource-intensive manufacturing processes. Moreover, the production process generates minimal carbon emissions, contributing to a reduced carbon footprint. Fungal materials are also biodegradable, supporting the concept of a circular economy and minimizing waste generation. Additionally, mycelium actively sequesters carbon from the atmosphere during its growth. {% embed url="" %} **Some of the companies working most interestingly and promisingly on this material are** [**Biohm**](https://www.biohm.co.uk/about)**,** [**Mogu**](https://mogu.bio/)**, and** [**Ecovative**](https://www.ecovative.com/)**.** These three companies (in the order British, Italian, and U.S.) each work from the mentioned substrates to make mainly insulation panels, acoustic panels, wall coverings, furniture, floors and packaging solutions. They each use mycelium biofabrication to create environmentally friendly and customizable alternatives to conventional materials, not only in construction, but across various industries - like packaging, fashion and food. For example, one of Ecovative's primary products is called Forager foam, a flexible and bio-based foam material that can be used in footwear, upholstery, and packaging applications. Forager provides a sustainable alternative to petroleum-based foams, offering excellent cushioning and shock-absorbing properties. As we have already emphasized, such solutions are currently a minority in the industry. Until we realize that we are surrounded by "zombie" technologies and materials (meaning “already without a future because they are made of unsustainable materials”, as explained in Daring Design), most companies will find it convenient to continue with their business as usual. At the same time, the most promising solutions require investment in research, legislative facilitations for their use, and applicability in regional contexts. Each location should be able to meet housing needs in a way that is most appropriate to the local context in terms of architectural design and readily available materials that respond to current and future climate conditions.