Vernacular Bahareque Architecture and Bioclimatic Performance: Multi-Criteria Assessment of Kichwa-Saraguro Dwellings in the Ecuadorian Andes

Abstract

The construction sector accounts for approximately 36% of global final energy consumption and close to 40% of total CO₂ emissions, making it a primary target of international climate policy. Despite this growing attention, the indigenous building traditions of the Ecuadorian Andes remain virtually absent from the international scientific literature on vernacular sustainability. This study presents a systematic field documentation and bioclimatic assessment of vernacular bahareque dwellings in the Kichwa-Saraguro community of Ilincho, canton of Saraguro, province of Loja, Ecuador (2700 m a.s.l.). A field survey of 30 dwellings identified five morphological typologies—I-1P, I-2P, 2B, L, and C—with typology C, a compact C-shaped block with a three-sided portal, accounting for 53.3% of the sample. A structured multi-criteria framework of 48 bioclimatic indicators distributed across eight categories, adapted to the cold-temperate mountain climate of the study area, was applied to quantify each typology’s bioclimatic performance. All typologies exceeded 75% overall compliance on the global Bioclimatic Performance Index (BPI), with typology C achieving the highest value (88.5%). Categories F (Materials and construction) and H (Cultural and social aspects) scored 100% across all typologies, reflecting system-level properties of the bahareque constructive system rather than morphological differences between typological variants; a supplementary morphological BPI restricted to Categories A–E and G is reported. An exploratory, uncalibrated energy simulation of typology C provided indicative evidence consistent with the expected thermal behavior of a high-thermal-mass bahareque envelope, with simulated minimum temperatures in the sleeping area within the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) 55-2013 comfort range (T-min 18.80 °C). Collectively, these findings contribute quantified bioclimatic documentation of vernacular bahareque architecture in Ilincho, identifying attributes—encompassing solar control, spatial compactness, high-thermal-mass envelope performance, and use of locally sourced low-embodied-energy materials—that may inform sustainable rural housing discussions in the Ecuadorian Andes and comparable high-altitude mountain contexts. Its documentation in the indexed scientific literature constitutes a step toward recognizing this constructive heritage as a practical resource for low-carbon building policy.

1. Introduction

The construction sector currently accounts for approximately 36% of global final energy consumption and close to 40% of total CO₂ emissions, making it one of the primary targets of international climate policy [1,2]. In Latin America and the Caribbean, building-related emissions have risen steadily over the past three decades, driven by rapid urbanization and the widespread displacement of traditional construction systems by energy-intensive industrial alternatives [2]. Against this backdrop, the search for culturally appropriate, low-carbon building solutions has renewed scholarly attention to vernacular architecture—the built tradition arising from the accumulated experience of communities responding to specific climatic, topographic, and cultural conditions using locally available resources [3,4,5,6,7]. A growing body of international research has documented that vernacular building practices across diverse climatic regions consistently incorporate passive bioclimatic strategies, including thermal mass regulation, natural ventilation, solar control, and the use of materials with low embodied energy [7,8,9,10,11]. Studies in cold-climate contexts—the mountainous regions of India [5,6], Central Europe [11], the Iberian Peninsula [12], and cold-region traditional architecture more broadly [10]—have documented the effectiveness of compactness, thermal mass, and solar orientation as dominant vernacular responses to cold-season thermal discomfort. Despite this growing literature, the Andean region of South America remains significantly underrepresented in comparative studies of vernacular bioclimatic performance, and the indigenous building traditions of highland Ecuador have received negligible systematic attention in the indexed scientific literature on this subject.

In Ecuador, vernacular earthen construction has been documented through heritage conservation studies [13] and analyses of passive architectural strategies [14], rather than through systematic bioclimatic assessment. Recent research on rural dwellings in Loja province has examined intermediate spaces as devices of social sustainability [15]; however, the quantified assessment of bioclimatic performance for these typologies remains unexplored. Among earthen construction systems documented in the Andean region, adobe (sun-dried earthen brick) and rammed earth (tapial) have received comparatively greater scholarly attention, with adobe thermal performance studied across diverse Latin American highland contexts. Wattle-and-daub techniques—known as bahareque, quincha, or bahareque across the region—have been less frequently examined in the bioclimatic literature, and their performance in high-altitude cold-temperate mountain environments remains largely undocumented. The bahareque system, a timber-framed wattle-and-daub technique, represents one of the most widespread vernacular construction systems in the southern Andes, yet its bioclimatic attributes have not been formally assessed in the indexed scientific literature.

To the best of the authors’ knowledge, based on a search of Scopus and Web of Science using the terms “bahareque” OR “wattle-and-daub” AND “Ecuador” AND “bioclimatic” OR “thermal performance,” no study has systematically documented and assessed the bioclimatic performance of vernacular bahareque dwellings in an Ecuadorian Andean indigenous community using a structured multi-criteria evaluation framework.

This study addresses the identified gap through a case study in the community of Ilincho, canton of Saraguro, province of Loja, at 2700 m a.s.l. A preliminary version of this work was presented as a conference paper [16], focusing on the documentation of the bahareque self-building process and an exploratory energy simulation. The present study substantially extends that prior work through three original contributions: a systematic typological catalog of five morphologies, a multi-criteria evaluation of 48 bioclimatic indicators with quantified performance indices per typology, and a comparative morphological analysis. Together, these contributions add a structured multi-criteria bioclimatic assessment of Kichwa-Saraguro bahareque housing to the limited indexed literature on vernacular architecture in highland Ecuador.

Three specific objectives are pursued: (1) to characterize the morphological and constructive typologies of the bahareque dwellings of Ilincho through systematic field survey; (2) to evaluate their degree of alignment with established passive bioclimatic design principles through a structured multi-criteria framework; and (3) to discuss the implications of these findings for sustainable rural housing policy in the Ecuadorian Andes and comparable high-altitude mountain contexts across Latin America.

2. Materials and Methods

2.1. Study Area

The community of Ilincho belongs to the Kichwa-Saraguro people and is in the canton of Saraguro, province of Loja, southern Ecuador (latitude 3°38′4′′ S, longitude 79°14′43′′ W, altitude 2700 m a.s.l.). The climate corresponds to the rainy continental mountain zone, with mean annual temperatures of 12–15 °C [17]. The community comprises approximately 160 families distributed across five sectors—San Vicente, Totoras, Ilincho, Cochapamba, and Bura—and covers an area of approximately 419 hectares, established as a consolidated settlement since approximately 1950. Ilincho was selected because it represents one of the few settlements in the southern Ecuadorian Andes where the bahareque system remains actively practiced (Figure 1), with construction processes embedded in community tradition and the broader Andean worldview. The territorial and settlement context of the study area, from regional to community scale, is shown in Figure 2.

2.2. Field Survey and Typological Classification

A systematic field survey of all 158 buildings in the community of Ilincho was conducted by Chalán-Saca [18], in collaboration with community authorities and the community elder (Sabio). Buildings were identified and georeferenced through participatory cartography developed jointly with the community, given the absence of prior cadastral documentation for this settlement. Buildings were classified by constructive system: bahareque, adobe, concrete block, or mixed. Of the 158 buildings, 57 (36.1%) employ earthen construction systems, of which 30 (52.6% of the earthen stock) use the bahareque system. These 30 dwellings constitute the complete census of the bahareque typology in the community; no sampling was applied. For each dwelling, the following eight attributes were recorded through direct field observation and architectural measurement: (1) plan configuration and morphological typology; (2) principal façade orientation; (3) number of stories; (4) portal type and configuration; (5) estimated built floor area; (6) constructive system components and their dimensions; (7) material documentation; and (8) photographic record. Typological classification was conducted inductively from this dataset, identifying recurrent plan configurations across the 30 dwellings and grouping them into morphological variants following established procedures for vernacular typological analysis [12]. The distinguishing criteria for each typological class are as follows: (i) typologies I-1P and I-2P are single-block linear (I-shaped) configurations differentiated by the number of stories (one and two, respectively), each with a portal on one side; (ii) typology 2B comprises two separate built blocks arranged around a partially enclosed exterior space, with a single-sided portal; (iii) typology L is an L-shaped single-block configuration forming two sides of an enclosed courtyard, with portals on two sides; and (iv) typology C is a C-shaped single-block configuration enclosing three sides of a central courtyard, with portals on three sides. The criteria of plan configuration (number of continuous sides forming the built perimeter), number of stories, and portal count thus jointly define the five typological classes. Three of the five identified typologies (I-1P, I-2P, and 2B) are each represented by a single dwelling; performance data for these typologies are reported as documentary records of individual buildings and should not be interpreted as statistically representative typological characterizations. The comparative bioclimatic analysis is centered on typologies C (n = 16) and L (n = 11), which together account for 90% of the surveyed sample. The bahareque system comprises a load-bearing timber frame with a wattle infill of cane and organic fibers (chincha) and a clay-straw plaster coating (embarre), as shown in Figure 1; the main constructive elements and dimensions are summarized in

Table 1. Main elements of the bahareque constructive system in Ilincho.

Constructive Element	Dimension/Description	Function
Corner and minor posts	Buried 50 cm, spacing ~40 cm	Vertical load-bearing structure
Horizontal braces (pilores)	Upper and intermediate levels	Horizontal bracing
Ridge columns (horcones)	0.90–1.20 m above intermediate walls	Ridge beam support
Top plate (solera)	12 × 20 cm square section	Perimeter top closure
Corridor columns	20–25 cm diameter	Portal support
Wattle infill (chaclla/chincha)	Tied at 10–15 cm spacing	Base for clay plaster
Clay-straw plaster (embarre)	~4 cm per face, 15 days drying	Cladding and thermal mass
Roof	Ceramic tile, slope 20–25%	Water and solar protection
Foundation	Stone pads at corners + 50 cm deep holes	Ground moisture insulation

Source: compiled by the authors from Chalán-Saca [18] and Torres-Gutiérrez et al. [16].

. The construction of bahareque dwellings is organized through collective community work practices (minga), including ceremonial stages that mark the principal construction phases; this social and cultural dimension is captured in Category H of the multi-criteria framework applied in Section 2.4 and is described in detail in the prior publication by the research team [16].

2.3. Spatial Pattern Analysis

For the three principal plan configurations (I, L, and C), a qualitative spatial and environmental pattern analysis was conducted, employing the pattern language nomenclature of Alexander et al. 1977 [19] as an analytical structure. The analysis identified recurrent features in: (a) functional spatial organization; (b) the relationship between built form and the agricultural and natural setting; and (c) the implicit passive climate control strategies embedded in the spatial configuration. This phase is qualitative and interpretive in nature; it does not produce quantitative performance data, and its findings are reported as qualitative patterns grounded in direct observation and inform the formulation of bioclimatic criteria in Section 2.4.

2.4. Multi-Criteria Bioclimatic Framework

A structured multi-criteria bioclimatic evaluation framework of 48 criteria distributed across eight thematic categories was applied: (A) site and context; (B) orientation and form; (C) natural ventilation; (D) solar control; (E) thermal mass and envelope; (F) materials and construction; (G) spatial organization; and (H) cultural and social aspects. Framework derivation and adaptation. The categorical structure and multi-dimensional approach to architectural sustainability adopted in this framework draw conceptual inspiration from the sustainability systematization proposed by Castillo Haeger and del Castillo Oyarzún 2015 [20], which organizes architectural sustainability into structured environmental, social, and economic dimensions with associated criteria developed for pedagogical purposes in architectural education. That systematization was not designed as an operational bioclimatic field evaluation instrument for vernacular dwellings and does not contain the specific 48 criteria applied in the present study; its contribution here is the categorical logic for organizing multi-dimensional sustainability criteria. The bioclimatic content of the framework—the specific criteria, their operational definitions, and their calibration to cold-temperate mountain vernacular conditions—was developed through synthesis with three established bioclimatic taxonomies: the comprehensive review of passive thermal comfort strategies by Manzano-Agugliaro et al. 2015 [9]; the cold-climate passive design framework of Tamaskani Esfehankalateh et al. 2022 [10]; and the quantitative typological bioclimatic evaluation approach of Khei et al. 2024 [21]. Three specific adaptations were introduced for the study context: (i) natural ventilation criteria (Category C) were recalibrated to reflect their heat-retention function in cold mountain climates, such that the deliberate minimization of air exchange is scored as a positive bioclimatic strategy; (ii) criterion density in Category E was increased to reflect the centrality of heat storage in the dominant comfort challenge of cold-temperate mountain environments; and (iii) Category H was introduced to capture collective construction practices and Andean cosmological elements embedded in the bahareque system. The complete list of all 48 criteria with operational definitions is provided in Supplementary Materials (Table S1).

Table 2. Summary of the eight-category multi-criteria bioclimatic framework applied in this study. The complete list of 48 criteria with operational scoring definitions is provided in Supplementary Materials (Table S1).

Category	No. of Criteria	Main Evaluated Aspects	Scoring Basis
A. Site and context	8	Topographic suitability; solar exposure; wind protection; relationship to natural landscape; vegetation as climate buffer; land use compatibility; microclimatic context; proximity to productive land	Direct field observation; comparison with climatic context data
B. Orientation and form	6	Principal façade orientation; plan compactness; form factor; roof geometry; self-shading capacity; solar incidence on main openings	Architectural measurement; compass observation; plan analysis
C. Natural ventilation	6	Distribution and size of openings; cross-ventilation potential; prevailing wind alignment; deliberate minimization of air exchange (recalibrated as positive strategy in cold mountain climate)	Field measurement of openings; observation of envelope continuity
D. Solar control	6	Provision of overhangs; portal as multi-façade shading device; window-to-wall ratio; solar gain through east/south openings; horizontal shading elements; seasonal solar geometry appropriateness	Architectural measurement; sun angle calculations for study latitude
E. Thermal mass and envelope	8	Wall thickness and mass; thermal conductivity of envelope materials; floor-to-ground separation; roof thermal performance; envelope air tightness; thermal bridge continuity; buffer zone effectiveness; heat storage and release behavior	Material documentation; dimensional measurement; normative reference (NEC-HS-EE)
F. Materials and construction	4	Use of locally sourced materials; low embodied energy content; absence of industrial processing; material durability and maintenance requirements	Material identification and provenance documentation; observation
G. Spatial organization	6	Functional spatial hierarchy; zone transition gradients from public to private; multi-functionality of interior spaces; integration of hearth as thermal and social center; spatial adequacy for climate-sensitive activities	Spatial observation; architectural plan analysis
H. Cultural and social aspects	4	Collective construction practices (minga); intergenerational knowledge transmission; cosmological and ceremonial elements embedded in construction sequence; community social cohesion outcomes	Ethnographic observation; prior documentation [16]
Total	48

provides a summary of the eight categories, the number of criteria per category, the main evaluated aspects, and the scoring basis applied in each case. Scoring procedure and index calculation. Each criterion was scored through direct field observation. A three-value ordinal scale was applied: 1 (fully compliant); 0.5 (partially compliant); and 0 (non-compliant). A Bioclimatic Performance Index (BPI) was calculated per category and as a global index per typology: BPI_category (%) = [Σ criterion scores in category/(n criteria in category × 1)] × 100 BPI_global (%) = [Σ all criterion scores/(48 × 1)] × 100 Note on invariant categories. Categories F (Materials and construction) and H (Cultural and social aspects) achieve 100% compliance across all five typologies, reflecting system-level properties intrinsic to the bahareque constructive system as a whole—locally sourced materials with low embodied energy, absence of industrial processing, and collective construction practices—rather than morphological differences between typological variants. Because these two categories are structurally invariant across the sample, the global BPI incorporates a system-level component common to all typologies. A supplementary morphological BPI restricted to Categories A–E and G is reported in Section 3.3 to isolate the contribution of plan morphology to bioclimatic performance.

2.5. Exploratory Energy Simulation

An exploratory energy simulation of typology C was conducted using Archicad 26 Building Information Modeling (BIM) software (Graphisoft, Budapest, Hungary; v.26.0.0) and its integrated EcoDesigner energy analysis module. This simulation is designated as exploratory because it is not calibrated against in situ monitoring data and is therefore unable to predict actual thermal conditions with quantitative accuracy; its purpose is to provide indicative evidence on the relative thermal performance of the three principal functional zones. Climatic data were imported from a typical meteorological year (TMY) EnergyPlus Weather (EPW) file obtained from EpwMap (Ladybug Tools; https://www.ladybug.tools/epwmap/, accessed on 15 March 2023) for the nearest available station to the Ilincho study site (3°38′ S, 79°14′ W; 2700 m a.s.l.). The BIM model reproduces the architectural plan of typology C as documented by Chalán-Saca [18]: floor area 67.28 m², treated volume 237.09 m³, exterior envelope area 183.88 m². The treated volume of 237.09 m³ corresponds to the total interior volume of the building model from floor level to the interior apex of the pitched ceramic tile roof (slope 20–25%), as automatically calculated by the EcoDesigner module from the BIM geometry; it incorporates the volumetric contribution of the roof cavity above the habitable floor. Three thermal zones were defined—sleeping area, living room, and kitchen. The three-sided portal is modeled as a semi-exterior zone. Occupancy schedules, metabolic heat gains, equipment loads, and artificial lighting were not modeled; the simulation is restricted to the passive thermal behavior of the envelope under climatic boundary conditions and is explicitly treated as an exploratory assessment of envelope performance rather than a full building energy model. Material thermal properties were assigned in accordance with the Norma Ecuatoriana de la Construcción—Eficiencia Energética (NEC-HS-EE) [22]. The specific thermophysical values applied to each envelope component are reported in Supplementary Materials (Table S2). Infiltration parameters were adopted in accordance with the Manual de Hermeticidad al Aire de Edificaciones [23] and calibrated to reflect the artisanal construction characteristics of the bahareque envelope: 3.3 L/s·m² for walls with openings; 0.7 L/s·m² for solid walls; 7.0 L/s·m² for the roof; and 5.0 L/s·m² for window frames. These values represent conservative assumptions; in situ air permeability measurements were not conducted. The simulation reported in the prior conference paper [16] applied a different parameterization; the present values were revised in accordance with [23], resulting in minor differences in simulated temperatures relative to the earlier report. All results correspond to the revised parameterization. Simulated interior temperatures were compared against the 18–25 °C range specified by ASHRAE Standard 55-2013 [24] for residential occupancy, used as a pragmatic reference threshold not specifically calibrated for this climatic and cultural context.

2.6. Methodological Limitations

The following limitations apply to this study and must be considered when interpreting the results. Three of the five identified typologies (I-1P, I-2P, and 2B) are each represented by a single dwelling; performance indices for these typologies reflect the characteristics of individual buildings rather than typological averages and should not be treated as representative values for those morphological classes. The multi-criteria bioclimatic assessment was conducted by a single evaluator, and inter-rater reliability was not formally tested; criteria based on directly observable physical attributes are less susceptible to evaluator subjectivity than those requiring interpretive judgement. The energy simulation is not calibrated against measured interior temperature or humidity data; results are indicative and cannot be interpreted as quantitative predictions of actual thermal conditions in the surveyed dwellings. The EPW file represents the nearest available meteorological station and may not fully capture the microclimatic variability of the Ilincho site, including topographic exposure effects and altitude-related radiative conditions. Finally, ASHRAE 55-2013 is applied as a pragmatic benchmark; adaptive comfort thresholds calibrated specifically for the Kichwa-Saraguro population in this climatic context have not been established in the scientific literature.

3. Results

3.1. Typological Characterization

Of the 158 buildings surveyed, 36.1% correspond to earthen construction systems, of which 30 dwellings (52.6% of the total earthen stock) employ the bahareque system. The typological analysis identified five distinct morphological variants (

Table 3. Typological distribution of bahareque dwellings in Ilincho (n = 30).

Typology	Description	Est. Area (m2)	Portal	n	%
I-1P	Compact I-shaped block, 1 story	~35	1 side	1	3.3
I-2P	Compact I-shaped block, 2 stories	~60	1 side	1	3.3
2B	Two compact blocks	~55	1 side	1	3.3
L	Compact L-shaped block	~55	2 sides	11	36.7
C	Compact C-shaped block	~70	3 sides	16	53.3
Total				30	100

Source: compiled by the authors from field survey data [18].

; Figure 3). Typology C, a compact C-shaped block with a three-sided portal, is the most prevalent, comprising 16 dwellings (53.3% of the sample), followed by typology L with 11 dwellings (36.7%). Typologies I-1P, I-2P, and 2B each account for one dwelling (3.3% each). All typologies share a general east-facing principal façade orientation, estimated at an azimuth of approximately 90°, consistent with solar gain optimization for morning warming in the cold mountain climate.

3.2. Spatial Patterns

The spatial pattern analysis (Figure 3) reveals consistent recurrences across all surveyed dwellings. All vernacular dwellings are organized around the hearth as a central spatial element, with multi-functional spaces integrating sleeping, storage, and social functions simultaneously. The portal serves as a sun-lit working space and a climate-buffered transition zone, with its greatest spatial development occurring in typology C, where it extends across three sides of the built volume. The plots consistently cultivated crops in the immediate perimeter, constituting a dwelling-agriculture system that responds simultaneously to productive and microclimatic management needs [19].

3.3. Bioclimatic Performance Index

Assessment across the 48 bioclimatic criteria shows that all typologies achieved global BPI values above 75% (

Table 4. Bioclimatic Performance Index (BPI) by category and typology (%).

Category	I-1P	I-2P	L	C	2B
A. Site and context	75.0	75.0	75.0	87.5	75.0
B. Orientation and form	75.0	75.0	83.3	83.3	58.3
C. Natural ventilation	66.7	66.7	66.7	83.3	58.3
D. Solar control	83.3	83.3	83.3	83.3	83.3
E. Thermal mass and envelope	75.0	75.0	75.0	81.2	75.0
F. Materials and construction	100.0	100.0	100.0	100.0	100.0
G. Spatial organization	83.3	83.3	83.3	100.0	66.7
H. Cultural and social aspects	100.0	100.0	100.0	100.0	100.0
Overall index (%)	81.2	81.2	82.3	88.5	77.1
Morphological BPI (A–E, G) (%)	76.4	76.4	77.8	86.4	69.4

Note: Categories F (Materials and construction) and H (Cultural and social aspects) achieve 100% across all typologies, reflecting system-level properties of the bahareque constructive system rather than morphological differences between plan configurations. The morphological BPI (last row) is restricted to Categories A–E and G, excluding the invariant Categories F and H, to isolate the contribution of plan configuration to bioclimatic performance. Source: compiled by the authors from field survey data [18].

). Typology C records the highest global BPI (88.5%) and typology 2B the lowest (77.1%). Categories F (Materials and construction) and H (Cultural and social aspects) achieve 100% across all typologies, reflecting system-level properties of the bahareque constructive system rather than morphological differences between plan configurations (Section 2.4). Because these two categories are structurally invariant, the global BPI includes a component common to all typologies regardless of plan morphology. To isolate the contribution of plan configuration to bioclimatic performance, a supplementary morphological BPI was calculated restricted to Categories A–E and G, excluding the invariant Categories F and H. Under this restricted index, typology C remains the highest performer (86.4%), while typology 2B falls to 69.4%—below the 75% threshold observed in the global index. Typologies I-1P and I-2P score 76.4%, and typology L scores 77.8%. This result indicates that the bioclimatic advantage of typology C is substantially attributable to its plan morphology—the three-sided portal configuration, volumetric compactness, and multi-functional interior organization—rather than solely to the material and cultural properties shared by all surveyed dwellings.

3.4. Exploratory Energy Simulation: Typology C

The energy simulation of typology C, characterized by a floor area of 67.28 m², a treated volume of 237.09 m³, and an exterior envelope area of 183.88 m², was conducted based on the architectural plan shown in Figure 4 and the BIM model presented in Figure 5. The resulting thermal performance is summarized in

Table 5. Energy simulation results by space—typology C (Archicad 26 + EcoDesigner).

Space	ASHRAE 55 Range	T-Min (°C)	T-Max (°C)	Assessment
Sleeping area	18–25 °C	18.80	29.20	Compliant (min.)
Living room	18–25 °C	17.20	33.30	Non-compliant
Kitchen	18–25 °C	15.90	29.90	Partially compliant

Note: all values are outputs of an uncalibrated exploratory BIM energy model and are indicative only; they do not constitute quantitative predictions of actual thermal conditions. Climatic data: TMY EPW file obtained from EpwMap (Ladybug Tools) for coordinates 3°38′ S, 79°14′ W. The treated volume of 237.09 m³ corresponds to the total interior volume of the building model from floor level to the interior apex of the pitched ceramic tile roof and includes the volumetric contribution of the roof cavity above the habitable floor. Source: Archicad 26 + EcoDesigner simulation [18].

; the complete EcoDesigner simulation output is presented in Figure 6.

The sleeping area records the highest simulated minimum temperature (T-min 18.80 °C), within the ASHRAE 55-2013 comfort range of 18–25 °C. This result is consistent with the expected thermal behavior of a zone enclosed by high-thermal-mass bahareque walls, which store heat during daylight hours and release it gradually through cold nights [21,25]. This consistency does not constitute empirical validation of thermal mass effectiveness; the simulation parameters were specified from normative and literature sources, and the model has not been calibrated against in situ measurements. The living room records the largest simulated thermal amplitude (16.10 °C), with a peak of 33.30 °C exceeding the ASHRAE 55-2013 upper threshold. A plausible contributing factor is direct solar gain through the three-sided portal during peak radiation hours; this attribution is interpretive and was not tested through sensitivity analysis. The kitchen records the lowest simulated minimum temperatures (15.90 °C), consistent with the higher infiltration rates applied to this zone in the model; the open hearth was not modeled as a heat source, and actual kitchen temperatures under occupied conditions may differ from the simulated values.

4. Discussion

4.1. Bioclimatic Performance in Comparative Perspective

The bioclimatic performance indices obtained, ranging from 77.1% to 88.5%, are consistent with findings reported in analogous studies conducted in other regions. Chandel et al. 2016 [7] identified thermal mass, compactness, and solar control as the most recurrent passive comfort strategies in cold mountain climates, a finding that aligns closely with the highest-scoring categories observed in this study (solar control: 83.3% uniform across all typologies; thermal mass: 75.0–81.2%). Fernandes et al. 2020 [4] similarly report that high-thermal-mass earthen walls are the primary determinant of interior thermal comfort in mountain climates, an argument directly applicable to the Andean context studied here. Furthermore, Ortiz-Carrillo et al. 2025 [26] confirm, in recent analyses of vernacular construction techniques in southern Ecuador, that bahareque presents lower thermal conductivity than concrete, affording superior insulation and greater indoor thermal stability. Mite-Anastacio et al. 2022 [27] additionally demonstrate that traditional bahareque panels exhibit favorable seismic behavior, including ductile failure modes and energy dissipation capacities comparable to those of reinforced concrete systems of equivalent cost.

The 100% compliance in Categories F (Materials and construction) and H (Cultural and social aspects) across all typologies reflects system-level properties intrinsic to the bahareque constructive system as a whole—locally sourced materials with low embodied energy, absence of industrial processing, and collective construction practices—rather than morphological differences between plan configurations. As established in Section 2.4, these categories are structurally invariant across the sample; the bioclimatic performance differential between typologies is more accurately captured by the morphological BPI (Categories A–E and G) reported in Section 3.3. This finding aligns with Dall’Orto and Monteros Cueva 2025 [15], who documented at the provincial scale in Loja that intermediate dwelling spaces function as key drivers of social sustainability and the intergenerational transmission of constructive knowledge.

4.2. Typology C as the Highest-Performing Configuration Within the Evaluated Sample

Typology C achieves the highest bioclimatic performance on both the global BPI (88.5%) and the morphological BPI (86.4%), with the highest scores in six of the eight evaluated categories. Its spatial configuration provides climate-buffered transition zones across three sides and establishes a graduated spatial hierarchy from the public exterior through the sun-lit portal to the private sleeping area. The three-sided portal functions simultaneously as a solar shading device for multiple façades, a sun-lit working zone, and an element that moderates involuntary air infiltration—a combination of passive functions that contemporary architecture typically achieves only through active mechanical systems [8,9]. The statistical predominance of typology C (53.3% of surveyed dwellings) is consistent with its documented bioclimatic superiority across six of the eight evaluated categories. While this alignment is suggestive, causal attribution requires caution: the prevalence of a given plan configuration in a traditional community may reflect the convergence of bioclimatic, structural, economic, and social factors accumulated over generations. Isolating the specific contribution of bioclimatic performance to the spatial prevalence of typology C would require dedicated ethnographic investigation beyond the scope of this study [12].

4.3. Limitations and Methodological Implications

The natural ventilation category yielded the lowest performance indices across typologies (58.3–83.3%), primarily reflecting the deliberate absence of cross-ventilation openings. This is a design feature intended to retain heat during cold mountain nights rather than to promote active airflow. The finding suggests that established bioclimatic evaluation frameworks require recalibration when applied to cold-climate contexts, assigning greater weight to thermal mass criteria and reduced weight to active ventilation indicators [10].

The exploratory energy simulation reveals differentiated thermal behavior across the three modeled zones that is consistent with the bioclimatic logic of the bahareque typology, though not confirmatory of it. The sleeping area records simulated minimum temperatures within the ASHRAE 55-2013 comfort range, a result consistent with the expected performance of a zone enclosed by high-thermal-mass bahareque walls [21,25]; as stated in Section 2.5, this consistency does not constitute empirical validation given the uncalibrated nature of the model. The living room peak temperatures above 33 °C under simulated peak solar conditions and the kitchen’s below-threshold minima are identified as performance conditions amenable to passive mitigation. The incorporation of deciduous vegetation along the portal perimeter—a strategy fully consistent with the vernacular material palette—represents the most contextually appropriate passive response to living room overheating and constitutes a productive subject for future simulation sensitivity analysis. These interpretations are grounded in architectural reasoning and consistent with the simulation outputs; their substantiation requires in situ monitoring or model calibration.

4.4. Implications for Sustainable Rural Housing Policy

The bahareque system of Ilincho operates simultaneously across material, social, and cultural dimensions. It employs locally sourced, low-embodied-energy materials; transmits technical knowledge across generations through the communal minga process; and produces collective social outcomes through shared construction. The documented BPI values (77.1–88.5%), combined with the material and constructive attributes quantified in Category F, position the system as a low-carbon building solution of documented relevance for the cold-temperate mountain climate of southern Ecuador.

The progressive displacement of the bahareque system by concrete block construction—driven by cultural perceptions of modernity documented across indigenous communities of Ecuador by Morocho Jaramillo et al. 2024 [28]—represents a concurrent reduction in bioclimatic performance, constructive knowledge transmission, and the use of locally sourced low-embodied-energy materials. A constructive system that achieves global BPI values above 77% without active climate control, using locally sourced materials with low embodied energy and through collective construction processes of minimal monetary cost, merits consideration in sustainable rural housing discussions and policy frameworks, as argued by Morales-Cristóbal et al. 2020 [29]. This argument is further supported by the thermal and seismic performance evidence documented for comparable Andean contexts by Ortiz-Carrillo et al. 2025 [26] and García-Espinosa et al. 2025 [30].

5. Conclusions

This study presents a systematic documentation and bioclimatic assessment of vernacular bahareque housing in the Kichwa-Saraguro community of Ilincho (Saraguro, Loja, Ecuador; 2700 m a.s.l.), contributing quantified evidence for a building tradition that, to the best of the authors’ knowledge based on the literature reviewed, has not previously been assessed through a structured multi-criteria bioclimatic framework in the indexed scientific literature.

Field survey of 30 dwellings identified five morphological typologies, with typology C predominating (53.3%) and recording the highest bioclimatic performance index (88.5%). Assessment across 48 criteria and eight categories showed that all typologies exceed 75% overall compliance, with the materiality and cultural aspects categories achieving 100% across all cases.

The exploratory energy simulation provided indicative evidence consistent with the expected thermal behavior of a high-thermal-mass bahareque envelope, with simulated minimum temperatures in the sleeping area (T-min 18.80 °C) within the ASHRAE 55-2013 comfort range. Living room peak temperatures above the upper comfort threshold and below-threshold kitchen minima were identified as conditions amenable to passive mitigation through vernacular strategies, principally the incorporation of deciduous vegetation along the portal perimeter. All simulation results are presented as indicative; no quantitative prediction of actual thermal conditions is intended.

Collectively, these results provide structured evidence that vernacular bahareque architecture in Ilincho possesses documented attributes of passive bioclimatic design—encompassing solar control, spatial compactness, high-thermal-mass envelope performance, and use of locally sourced materials with low embodied energy—that support its consideration as a relevant vernacular case for sustainable rural housing discussions in the Ecuadorian Andes and comparable high-altitude mountain contexts. Its systematic documentation in the indexed scientific literature constitutes a step toward the recognition of this constructive heritage as a practical resource for low-carbon building policy.

Future research priorities include: (i) in situ temperature and humidity monitoring to calibrate the energy model; (ii) blower-door air permeability measurements of the bahareque envelope to validate infiltration assumptions; (iii) inter-rater reliability testing of the 48-criterion evaluation framework; (iv) extension of the typological survey to other bahareque communities in the southern Ecuadorian Andes; (v) ethnographic investigation of the factors underlying the statistical predominance of typology C; and (vi) development of an adaptive comfort model calibrated for cold tropical mountain climates and the indigenous populations inhabiting them.