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In the northwest of France, raw earth has been broadly used, especially in Brittany where cob dwellings have been built since the sixteenth century. Today, cob buildings represent 20 % of the built heritage on this territory (Bardel P., Maillard J-L. 2009). The cob technique is also found in the Vendée marshes, where squat dwellings (“bourrines”), dating back to the fourteenth century, bear witness to the use of local, natural resources (Patte E., Streiff F. 2006; Bonnet S., Alzeort D, Poullain P. 2021). Between these two well-documented earth-building territories lies the Guérande Peninsula where earthen heritage, until recently little-known and neglected, has become the object of study.As a result of several inventories undertaken by earth-building professionals, a part of this heritage has been recorded and mapped (Hilton A. 2016; Miranda Santos M. 2016; Humblot D., Josset F., Marquis B. 2018). Two main research methods have been used: · a general audit of the specific areas of the peninsula where earth buildings exist,· a targeted audit of certain villages and their buildings.This latter entailed a comparison of historical maps with current cadastral maps, followed up by on-site verification.Following this inventory work, a sense of the nature and extent of local earthen heritage is beginning to emerge, feeding synergies with renewed local interest in earth construction. The Maison Neuve eco-district in Guérande presents a clear example of this: its objective is to reuse several thousand tonnes of its own site-excavated earth in earth-building projects over the next 5 years. The results of the inventory work helped this local project to understand the nature of the earth available and the different relevant earth-building techniques. The inventory work has also fed into local educational and awareness-raising activities to raise awareness of local earth-built heritage and disseminate best practice in the renovation of earthen walls

The global challenge of large-scale climate change mitigation requires action also in the building and construction sector. From a life cycle perspective, and considering the mitigation timeframe, the issue of reducing embodied GHG emissions is gaining attention. Effective ways to reduce embodied GHG emissions have been proposed by the use of fast-growing, bio-based materials, due to carbon sequestered in the biomass. Another promising, yet largely under-explored option is to harness the environmental potentials and low embodied GHG emissions of earth-based materials for building construction. Earth construction dates back from 10,000 to 8000 BC and has been derived in many vernacular construction techniques. More recently, some earthen techniques have been modified, using stabilizers, mainly cement and lime, to increase strength and water stability. The objective of this article is to compare existing literature performed on the LCAs applied to various earthen construction techniques and seek for key factors. Transports as well as binder stabilizations are very influent on the results. Climate, nature of local soil, and geographical context are very influent on functionalities of buildings, mix design and transports, themselves influencing environmental impacts. According to design choices and local context, earthen construction is not always better than concrete. This means that no universal solution can be recommended with the LCA of an earthen wall. The solution has to be adapted to the local context. All references comparing walls material to conventional materials at the building scale, find better environmental performances of earthen walls compared to fired brick walls. However, a full comparison between earthen construction and conventional materials should account for the use phase: combining LCA models with thermal and durability models is a key research issue. Finally, it certainly would be useful to seek for solutions with best environmental performances in a local context, accounting for the nature of soil, the building's functional requirements as well as geographical and cultural specificities. Such an approach would ensure to lower environmental impacts but represents a drastic change in current construction practices. Whereas today building materials are standardized in order to fit with construction working practices, this paradigm shift would require to adapt construction working practices to the local material and context. As earthen construction is today, in many countries of the world, a re-emerging technique, and new professional practices are yet to be established, it seems possible to make this paradigm shift happen. Certainly, in the current context of the need to substantially reduce building-related GHG emissions, there is still strong potential in earth construction techniques for both research and building practice.

Earth based building materials having low or negligible carbon footprint are looked upon as a sustainable alternative building material in the construction sector. The confidence of using any building material is augmented with through understanding of its mechanical properties. A brief review on the mechanical properties of the building materials such as Rammed Earth, Earth Blocks (Adobe, Compressed Earth Block, and Extruded Blocks) and Cob, which are manufactured using raw earth or by adding very little additives are presented in this chapter. The mechanical behaviour of earth based building material is highly dependent on raw material, manufacturing technique and testing conditions. Therefore it is highly recommended to conduct through experimental campaign for every soil mix. This chapter also presents various experiments recommended to study the mechanical properties of the materials.

Based on the RILEM Technical Committee 274-TCE work, this paper is a discussion of the remaining engineering challenges faced by earthen architecture. The assessment of earth material performances requires the development of appropriate procedures and standards. This is discussed in particular for the characterisation, hygrothermal behaviour, mechanical behaviour, and durability of earth materials. One other important challenge, since one of the main advantages classically put forward, is its ecological performance, is a proper assessment of life cycle assessment of earth materials, elements and buildings. Moreover, the paper develops why the approach to earthen construction must be different compared to the dominant construction materials, to preserve its ability to contribute to the ecological transition in the construction sector. In particular, the needs of using local soils, with an architectural approach coping with the limits of the materials, and developing an architectural optimisation to preserve the earthen materials multifunctionality rather than selecting a sole property to be maximised. Lastly, the findings of the paper can be used to develop a holistic approach to earthen construction to foster the development of new earthen architecture projects.

The need for a vast quantity of new buildings to address the increase in population and living standards is opposed to the need for tackling global warming and the decline in biodiversity. To overcome this twofold challenge, there is a need to move towards a more circular economy by widely using a combination of alternative low-carbon construction materials, alternative technologies and practices. Soils or earth were widely used by builders before World War II, as a primary resource to manufacture materials and structures of vernacular architecture. Centuries of empirical practices have led to a variety of techniques to implement earth, known as rammed earth, cob and adobe masonry among others. Earth refers to local soil with a variable composition but at least containing a small percentage of clay that would simply solidify by drying without any baking. This paper discusses why and how earth naturally embeds high-tech properties for sustainable construction. Then the potential of earth to contribute to addressing the global challenge of modern architecture and the need to re-think building practices is also explored. The current obstacles against the development of earthen architecture are examined through a survey of current earth building practitioners in Western Europe. A literature review revealed that, surprisingly, only technical barriers are being addressed by the scientific community; two-thirds of the actual barriers identified by the interviewees are not within the technical field and are almost entirely neglected in the scientific literature, which may explain why earthen architecture is still a niche market despite embodying all the attributes of the best construction material to tackle the current climate and economic crisis. This article is part of the theme issue ‘The role of soils in delivering Nature's Contributions to People’.

Past builders have developed very low-embodied energy construction techniques optimizing the use of local building materials. These techniques are a source of inspiration for modern sustainable building. Unfortunately, this know-how was orally transmitted and was lost as earth construction fell into disuse during the 20th century in European countries. The absence of written documents makes necessary to use an archaeological approach in order to rediscover these construction strategies. Micromorphological analysis of thin sections collected in earth building walls was used for the first time to describe cob construction technique and highlighted several typical pedofeatures allowing to clearly identifying this process. Finally, a first comparison of the cob and rammed earth micromorphological features permitted to identify two key factors to distinguish these two techniques, the manufacturing state (solid or plastic) and the organization of the material in the wall. Keywords: Cob, Rammed earth, Micromorphology, Architectural heritage, Pedology

In the European Union, most of the wastes from the building sector are composed of earths. Earth construction may be an interesting outlet for the re-use of these wastes, while meeting the challenge of circular economy: in particular, it involves low-embodied energy processes and earth material can be re-used for building by end-of-life. Nonetheless, the identification of suitable earths for construction remains an issue. To overcome this problem, an option may be to analyse earth building heritage, which is at least one-century old in Europe: indeed, earth employed in these buildings can be regarded as “time-tested”, and thus suitable for construction. In this paper, more than 20 different earths collected in rammed earth heritage building in France are presented. The results are confronted both to literature and to several classifications employed in soil sciences. A classification system based on granularity and clay activity will be relevant to address the convenience of earth for building purposes.

Bio-based materials are subject to a growing interest since the nineties to reduce the environmental impacts of the building sector. Light earth is a low impact insulation material. Light earth building methods are based on the use of earth slip, a mix of clayed earth and water, and aggregates or fibers. The earth slip is characterized on site by mason by different means. This study aims to compare different rheological measurements methods in laboratory conditions, and then to define simple and robust tests adapted to any conditions. The study is based on six soil samples. Geotechnical characterizations show that these soils cover a wide range of natural variabilities. Their cohesive behaviors were investigated by measuring the yield stress with a rheometer, a spread test, a dipping test and a rough wall cone test, both developed for the study, and a Marsh cone test. Accuracy and the validity range of each test are presented alongside the needs for light earth applications.

We propose herein the design of a heat exchanger based on clay materials in order to reduce the energy consumed due to data center cooling. Our Thermal Energy Storage (TES) system is to be placed upstream of the CRAC (Computer Room Air Conditioner) unit. A direct contact heat exchanger is thereby built as a vertical packed bed, composed of earthen spheres whose imposed heating/cooling cycles comply with ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) standards. A raw earthen material has been chosen owing to its hygrothermal characteristics, which are recognized as relevant for indoor thermal regulation, in addition to a low embodied energy required for manufacturing. Results show that the pore Reynolds number and sphere diameter exert significant effects on the energy buffering capacity. A simple relationship is thus proposed to link the mass-specific power of the energy storage system, the internal heat exchanger architecture and the pore Reynolds number for purposes of designing raw earth bricks at an elevated scale.

The present study aims to evaluate the impacts of raw material variability (earth and hemp) on hemp–earth performances. This work is performed in the framework of the ECO-TERRA R&D project in collaboration with four French research laboratories, short circuit hemp producers and craftsmen specialized in hemp and earth constructions. This article is focused on the thermal conductivity and mentions preliminary results of the mechanical characterizations. The results are compared to lime–hemp materials. The typical volumetric mass of a dry lime–hemp mixture is about 330–400 kg/m3, which corresponds to a thermal conductivity about λ = 0,11 W m−1 K−1.

Results of a European round-robin aiming to identify and quantify scattering sources impacting the polished stone value (PSV) of aggregates, and to assess the reference PSV of Herrnholzer granite, are presented and discussed. This reference value corrected against quartz dolerite control stone is calculated as PSV ref HE = 56.1 ± 0.5. According to variance analysis calculations, PSV scattering sources breakdown into three main components which have been assessed, a random friction tester term and two biases caused by test specimen preparation and polishing machine. Further investigation carried out on machine parameters using principal component analysis (PCA) reveals that narrowing the tolerance on flour emery flow rate should mitigate the machine bias. The results also evidence a higher scattering for low PSV aggregates, and PCA shows that this relates to their higher sensitivity to wheel speed variability not accounted for by the PSV control stone correcting factor. Besides, the results suggest enlarging the validity range of residual friction measured on PSV control stone prescribed by European standard EN 1097-8:2009, and they raise issues relating to test specimen preparation. Eventually, results and suggestions of the present study will be implemented in the ongoing revision of EN 1097-8:2009.

This experimental study provides complete datasets of hygrothermal properties of numerous hemp-clay with density ranging from 200 to 350 kg m-3 for building thermal insulation. In addition, attention is also paid on protocols and methods, on the measurements repeatability and on the influence of conditioning temperature and relative humidity: mean uncertainties do not exceed 10% for all measurements, while initial conditioning influences at most the results, particularly for the sorption isotherm. Heat and moisture storage properties depend obviously of the constituent (hemp or clay). Furthermore, they can be estimated with a good accuracy with a mixing law. Thermal conductivity of the composites ranges between 0.06 and 0.12 W m-1 K-1 and clearly depends on the density. Water vapor diffusion resistance factor ranges between 2.24 and 4.14, while capillary absorption coefficient ranges between 0.027 and 0.135 kg m-2 s-0.5.

ISI Document Delivery No.: GE4BB Times Cited: 0 Cited Reference Count: 58 Hamard, Erwan Lemercier, Blandine Cazacliu, Bogdan Razakamanantsoa, Andry Morel, Jean-Claude Elsevier sci ltd Oxford; A new methodology based on the cross-referencing of spatialized pedological and heritage data is proposed to identify and quantify soil resources available for earth construction. The paper underlines the pedological particularities of areas containing earth heritage and uses these particularities to propose criteria to assess the suitability of soils for modern earth construction. The methodology applied at the regional scale in France (for a given area of 27,200 km2 in Brittany) enabled to specify five new texture classes (balance between clay, silt, sand and gravel content) of suitability for cob soils. This result calls into question recommendations available in the literature. The methodology also provides data on the scale of availability of the resource to repair earth built heritage (cob) or to build new low impact buildings with integrated modern cob walls. In the studied area the potential waste recovery of 2.8 Mt per year is measured, highlighting the large availability of materials for earth construction. At least 23% of earthwork wastes of Brittany are suitable for earth construction (0.7 Mt). However, earth remains a non-renewable material and this resource has to be properly managed, requiring an appropriate building design and maintenance in order to increase longevity and to avoid the use of admixture, preventing earth reversibility at end of life.

Deformations observed within Quaternary alluvium in the Champagne region (Paris Basin) comprise faults, folds and soft-sediment deformation structures. Their occurrence is linked to the subjacent weathered chalk. Previously interpreted as neotectonic features, the deformations are reinterpreted as karst subsidence features or/and soil displacements due to periglacial processes. Dissolution of chalk has produced superficial subsidence, explaining the geometry of some faults and their large offsets within surface deposits. The freezing-thawing cycles in the porous superficial layers have also favoured gravity instability and deformations, and this can explain local small-scale deformations but also mass movement (sliding). The seismotectonic hypothesis is rejected, because of the absence of regional faults able to generate such large co-seismic offsets. The fault directions and the apparent vertical offsets are not homogeneous at regional scale and they are often inconsistent with the Quaternary stress field. Moreover, the rooting of faults into the basement is not documented and therefore, the neotectonic origin is very doubtful.

This work deals with the characterization of fragmentation of recycled concrete aggregate (RCA) by the Los Angeles test. The standard testing procedure for the Los Angeles index requires the measurement of the mass passing 1.6 mm after 500 revolutions of the drum. Questions arise on the significance of this measure for RCA as the resistances of the mortar, of the original aggregate and of their interface simultaneously affect the measurement result. In order to clarify the interpretation of such a measure, three aspects were investigated: the influence of the number of revolutions, the evolution of the full particle size distribution and the distribution of mortar in the fractions after the test. The results suggested that the fracture mechanisms are similar between recycled and natural aggregates with some quantitative differences. RCA was less resistant to fragmentation and displayed a non linear evolution of mass passing 1.6 mm with the number of revolutions. During fracture of RCA, mortar progressively accumulates in smaller fractions, with coarse fractions asymptotically behaving like natural aggregates. The analysis of the rate of breakage of the coarsest fraction appeared to be a richer indicator of crushability as a function of time and composition than the amount of the mass passing 1.6 mm: its typical evolution allows estimating a rate of breakage which correlates well with indirect measures of composition (water absorption and density). The possible existence of an asymptote in the rate of breakage of the coarsest fraction suggests that it can be used to estimate at the same time the resistance of the recycled aggregate and of its original natural component, and probably give an estimate of the amount of mortar.

In this paper, we compare different methods for determining the water absorption of recycled aggregates (RAs) and, highlighting advantages and critical points, attempt to suggest alternatives for a better way to measure it. Water absorption (WA) capacity has two purposes: (a) measuring the interconnected porosity, which is useful for mechanical concrete analysis and durability issues, and (b) allowing adjustment of the amount of water used in concrete production. Our analysis shows that vacuum during soaking is recommended for the RAs’ interconnected porosity determination. This approach enables shorter testing time (from ⩾24 h to ⩽1 h) and increases the accuracy of the measurement. The saturated surface dry (SSD) state determination can also be fastened using centrifuge, air flow drum, laser scattering, and microwave drying evaporometry, without significant differences. The use of these techniques is still restricted due to such factors as commercial availability, geometric limitations of the sample containers, and difficulty in controlling the temperature and the relative humidity. For concrete production, WA kinetics during the first 30 min is fundamental. Accuracy of the results is arguable regarding the practical issues, for example, vibration or trapped air bubble. Mathematical artefacts can overcome those problems but need to be calibrated with experimental data determined by standard tests over time. Because the WA kinetics probably changes when RAs are in contact with cement paste, a method to understand and quantify this phenomenon is still a research demand.

The will of reducing environmental and social impact of building industry has led to a renewed interest in earth construction. Most of earth construction literature dealt with rammed earth or adobe techniques, but very little with cob. Yet, cob participates in the diversity of vernacular earth construction processes that value local materials and is an alternative to rammed earth and adobe in specific geographical conditions. Conservation of cob heritage also requires a better knowledge of this vernacular construction process. This bibliographical analysis gathered extensive data on cob process and summarized the different cob process variations, attempting to take into account their diversity. This analysis allowed us to provide novel data on cob process, and more specifically, (1) a clear definition of cob with regard to other earth construction processes, (2) a first summarized description of cob process that clearly distinguished its variations, (3) a list of fibres traditionally employed, (4) values and, if possible, average and standard deviation for fibre length, fibre content, manufacture water content, drying times, lift heights and wall thicknesses, (5) a summary of the strategies to manage shrinkage cracks, (6) a criterion on the quality of implementation and/or earth for cob, based on slenderness ration of lifts and (7) a discussion on the evolution of cob process with regard to societal evolutions.

Rammed earth was traditionally used in western European countries before industrial building materials replace it during 20th Century. Construction strategies developed by former builders were dictated by locally available construction materials and engendered local constructive cultures. Unfortunately, this knowledge was orally transmitted and is lost today. The rediscovery of these cultures can provide answers to modern rammed earth construction processes. Micromorphological analysis of earth walls provides information to rediscover traditional rammed earth process. This methodology is applied for the first time, on a rammed earth wall of a farm located in Bresse (France). Thanks to this methodology, pedological horizon, extraction depth and location of the material source are identified. The surface area excavated for the construction of the building is estimated. Micromorphological study gives information on mixing degree and water content at implementation time. Strain features associated with ramming effect and rammed earth boundary layer are also highlighted. Running Head: Rammed earth micromorphological analysis

Physicochemical characteristics of Hibiscus cannabinus (kenaf) fibers from Burkina Faso were studied using X-ray diffraction (XRD), infrared spectroscopy, thermal gravimetric analysis (TGA), chemical analysis and video microscopy. Kenaf fibers (3 cm long) were used to reinforce earth blocks, and the mechanical properties of reinforced blocks, with fiber contents ranging from 0.2 to 0.8 wt%, were investigated. The fibers were mainly composed of cellulose type I (70.4 wt%), hemicelluloses (18.9 wt%) and lignin (3 wt%) and were characterized by high tensile strength (1 ± 0.25 GPa) and Young’s modulus (136 ± 25 GPa), linked to their high cellulose content. The incorporation of short fibers of kenaf reduced the propagation of cracks in the blocks, through the good adherence of fibers to the clay matrix, and therefore improved their mechanical properties. Fiber incorporation was particularly beneficial for the bending strength of earth blocks because it reinforces these blocks after the failure of soil matrix observed for unreinforced blocks. Blocks reinforced with such fibers had a ductile tensile behavior that made them better building materials for masonry structures than unreinforced blocks.

As part of a working definition of a new code of practice, this paper develops a methodology to determine the suitability of plasters manufactured on-site to protect the earthen walls of vernacular architecture buildings. Given the diversity of raw earth construction types, ranging from massive earth to stone masonry with earth mortars, and the variability of the materials used, two on-site tests (a shrinkage test followed by a shear test) were proposed. Those tests, as well as additional tests, were performed with lime/sand, earth/sand and earth with plaster admixtures. Lime/sand plasters do not typically pose shrinkage issues, which is why more earth based specimens were tested than lime based specimens. An analysis of the on-site testing complemented with laboratory tests reveals an antagonistic control of the bond between earth plaster and earthen wall based on clay content: an increase in the plaster clay content leads to increased bending strength, which strengthens the plaster and increased shrinkage, which weakens the plaster-wall interface. The heterogeneity of the wall leads to a wide range of results; therefore, this study was conducted to validate the formulation of plasters by means of shrinkage and shear tests at five different points on the wall. The shrinkage test allows finding the earth plaster formulations. Among all the validated formulations, the mason chooses the best one thanks to two criteria: the best workability (which is variable according to masons) with the highest clay content as possible. Then, when the formulation is chosen, the shear test must be done to verify if the bond between the plaster and the wall is high enough. This series of tests allows masons to validate formulations that will ensure good mechanical resistance of the plasters that protect buildings of vernacular earthen architecture.

As the starting point of this discussion, we would like to congratulate the authors for this interesting review [1] , which defends the use of earth as a building material. Indeed, while this is one of the oldest building materials in the world, it is also one of the less studied by the scientific community, and thus, one of the less understood. However, a s stated by the two authors of this review, the number of scientific studies on this subject has increased dramatically in recent years..

Durability of earthen structures is mainly dependent on the action of water on the walls. In this chapter, the relevance of the current tests measuring the resistance of earthen material to water is analysed and some pertinent tests are suggested to corresponding domains of application. The second part of the chapter deals with the use of plaster to increase durability. The validation of the plaster is proposed thanks to two in situ tests: the shrinkage test and the shear test for surface coatings. The long-term performance of earthen material is then analysed through research that has been conducted on walls exposed to natural climatic conditions for several years.

L'utilisation de matériaux locaux, naturels et non transformés offre des solutions prometteuses de construction à faible impact environnemental. La grande variabilité spatiale de ces matériaux est cependant un obstacle à une utilisation à plus grande échelle. Les stratégies de construction développées par les anciens bâtisseurs ont été dictées par le climat local et la qualité ainsi que la quantité de matériaux de construction disponibles localement. Ces stratégies de construction peuvent être considérées comme une gestion optimisée des ressources locales, naturelles et variables et sont une source d'inspiration pour la construction durable moderne. Malheureusement, cette connaissance a été perdue dans les pays occidentaux au cours du 20ème siècle. La redécouverte des savoir-faire traditionnels requiert le développement de moyens rationnels d'analyse du patrimoine. Un autre problème concernant l'utilisation de matériaux de construction naturels et variables est leur conformité vis-à-vis de la réglementation du secteur du bâtiment. Le développement de procédures d'essais performantiels est proposé comme solution pour faciliter l'utilisation des techniques de construction en terre. Une approche multidisciplinaire est proposée, combinant micromorphologie, pédologie, géotechnique et étude du patrimoine pour analyser le bâti vernaculaire en terre. Cette approche fournit des outils complémentaires pour évaluer la source des matériaux de construction et identifier les caractéristiques géotechniques de la terre employées dans le patrimoine. Il fournit également une description détaillée des processus vernaculaires de construction. En utilisant ces résultats, il a été possible d'élaborer des cartes de ressources et d'estimer l'ordre de grandeur de la disponibilité des ressources à l'échelle d'une région. Deux procédures d'essais performantiels ont été proposées afin de tenir compte de la variabilité naturelle des terres dans le contexte réglementaire actuel. La construction en terre jouera un rôle important dans la construction durable du 21ème siècle si les acteurs du secteur adoptent des procédés de construction capables de répondre à la demande sociale, avec un faible impact environnemental et à un coût abordable. L'étude du patrimoine en terre a démontré la capacité des anciens bâtisseurs à innover afin de se conformer aux variations de la demande sociale et aux développements techniques. La construction en terre bénéficie d'un passé ancien et riche et il convient de tirer profit de ce retour d'expérience. L'analyse du patrimoine en terre et la redécouverte des techniques de construction vernaculaire est une source d'inspiration précieuse pour la construction contemporaine. La valorisation des connaissances vernaculaires permettra d'économiser du temps, de l'énergie et d'éviter de répéter les erreurs passées. L'avenir de la construction de la terre doit s'inscrire dans la continuité de la construction en terre vernaculaire. The use of local, natural and unprocessed materials offers promising low impact building solutions. The wide spatial variability of these materials is, however, an obstacle to a largescale use. The construction strategies developed by past builders were dictated by the local climate and the quality and the amount of locally available construction materials. These construction strategies can be regarded as an optimized management of local, natural and variable resources and are a source of inspiration for modern sustainable building. Unfortunately, this knowledge was lost in Western countries during the 20th century. Vernacular earth construction know-how rediscovering requires the development of rational built heritage investigation means. Another issue regarding the use of natural and variable building material is their compliance with modern building regulation. The development of performance based testing procedures is proposed as a solution to facilitate the use of earth as a building material. A multidisciplinary approach is proposed, combining micromorphology, pedology, geotechnics and heritage disciplines to study vernacular earth heritage. It provides complementary tools to assess pedological sources of construction material and geotechnical characteristics of earth employed in vernacular earth heritage. It also provides a detailed description of the construction process of vernacular earth heritage. Using these results, it was possible to draw resource maps and provide a scale of magnitude of resource availability at regional scale. Two performance based testing procedures were proposed in order to take into account the natural variability of earth in a modern building context. Earth construction will play an important role in the modern sustainable building of the 21st century if the actors of the sector adopt earth construction processes able to meet social demand, with low environmental impact and at an affordable cost. The study of earth heritage demonstrated the ability of historical earth builders to innovate in order to comply with social demand variations and technical developments. Earth construction benefits of an old and rich past and it would be a non-sense to leave this past behind. The analysis of earth heritage and the rediscovering of vernacular construction techniques is a valuable source of inspiration for modern earth construction. The valorisation of vernacular knowledge will save time, energy and avoid repeating past mistakes. The future of earth construction should be a continuation of past vernacular earth construction.