The review, conducted by Anthony B. Sholanke and David Agbetoye of Covenant University in Nigeria, followed a PRISMA-informed search, screening, and thematic synthesis process. The authors identified 71 records, removed duplicates and off-topic entries, and settled on 37 studies published between 2020 and 2026, drawn from Google Scholar, the Covenant University Repository, the Multidisciplinary Digital Publishing Institute, and ResearchGate. Because the included studies varied so widely in building type, climate, and method, the authors judged a quantitative meta-analysis statistically indefensible and instead organized the evidence around three recurring themes: natural ventilation as a thermal purge mechanism, the strategic placement of thermal mass, and the integration of both with phase change materials.

The core physical logic of the strategy is straightforward. Thermal mass, in the form of concrete slabs, masonry walls, or earth-based construction, absorbs excess heat during occupied daytime hours, delaying the rise of indoor air temperature. Then, overnight, natural ventilation flushes cool outside air across those surfaces, extracting the stored heat and recharging the mass for the next day’s cycle. The review describes this as a thermal purge: the building’s fabric acts as a heat sink by day and is reset by night, potentially lowering the starting temperature of the interior each morning and reducing the burden on any mechanical cooling system.

Several mechanisms drive the purge. Cross-ventilation exploits pressure differentials between windward and leeward facades, while the stack effect, buoyancy-driven flow through solar chimneys, atria, and high-level clerestory openings, sustains airflow even on windless days. Courtyards and atria can act as the building’s lungs, breaking up deep plans and, when landscaped with vegetation or water features, pre-cooling incoming air. The authors note that institutional buildings, with their elongated plans and repetitive spatial modules, may be particularly well suited to such strategies, provided internal partitions do not obstruct the flow.

Placement of the mass matters as much as its quantity. The review emphasizes that unshaded external mass walls exposed to intense tropical sun can become heat reservoirs that radiate warmth into interiors well into the evening, increasing rather than reducing cooling loads. The recommended pattern is therefore to concentrate mass in internal partitions, floor slabs, and structural cores, kept exposed to indoor air rather than buried behind gypsum board or insulation, while external envelopes rely on shading devices, overhangs, ventilated cavities, and double-skin facades to limit solar gain before it reaches the heavy layers.

One of the most striking technical findings comes from a single simulation study included in the review, which modeled internal thermal mass under idealized cyclical design-day conditions. That study found the relationship between mass thickness and peak cooling-load reduction is nonlinear: beyond an optimum of roughly 28 to 45 millimeters for the internal mass layer, additional mass became counterproductive, presumably because the material could not be fully discharged overnight. The same study reported that granite as an internal mass material was about three times more effective than concrete of comparable thickness, and that pairing a lightweight envelope with internal mass cut peak cooling load by a further 35.9 percent. The review’s authors are explicit that this figure is an illustrative, single-study benchmark, dependent on one material, one modeling method, and one set of climate assumptions, and should not be read as a universal design rule.

Phase change materials add a modern twist to the old heavy-wall approach. Rather than storing sensible heat through high density, PCMs absorb large amounts of latent heat as they melt, offering far higher energy storage density in thin layers that can be integrated into ceiling tiles, wallboards, or floor slabs. Materials with transition temperatures near the desired indoor comfort range, around 24 to 26 degrees Celsius, can moderate the temperature spikes that would otherwise trigger air conditioning. But the review stresses that PCMs only work if they fully re-solidify overnight, a regeneration cycle that depends entirely on effective night flushing directed across the PCM-enhanced surfaces. Without that purge, the material saturates and stops performing.

The review is notably candid about the limits and contradictions in the evidence. Only 10 of the 37 included studies, about 27 percent, are directly institutional or tropical in context; the remainder are mechanistically informative but require local validation before prescriptive application. The authors also flag genuine disagreement in the wider literature about whether thermal mass works at all in climates with a narrow diurnal temperature range, a condition common in humid-equatorial settings. A field study of vernacular earth buildings in Costa Rica recorded peak-temperature damping of roughly 5 degrees Celsius in heavyweight construction, moderating but not eliminating that concern. More troubling, a Scopus- and Web of Science-indexed review found that in terraced houses in Johor Bahru, Malaysia, night flushing with high thermal mass reduced peak indoor temperature by about 2.5 degrees Celsius but did not meaningfully improve daytime comfort at 65 to 77 percent relative humidity; ceiling fans were needed to recover an additional 4 degrees of Standard Effective Temperature reduction. In other words, night flushing reliably removes stored heat, but translating that into occupant-perceived comfort in hot-humid climates may require pairing with fan-assisted air movement.

Practical barriers also loom large. Night flushing requires vents or windows to remain open and unobstructed overnight in buildings that may be unattended, raising concerns about security, weather ingress, and insects, which points toward lockable, screened ventilation hardware rather than fully open windows. Effective operation also depends on consistent control, opening vents at the right time and closing them before daytime heat begins, something the review says is poorly served by the heuristic, rule-based scheduling still common in tropical buildings. The authors point to predictive, potentially AI-driven ventilation control as a promising alternative to static schedules.

For architects and campus administrators, the review’s recommendations are framed as evidence-informed starting points rather than validated specifications: concentrate thermal mass in internal partitions and cores, keep heavy elements exposed to indoor air, use mixed-mode ventilation with night flushing to reset thermal inertia before occupancy, and deploy solar chimneys or atria to sustain buoyancy-driven purges during still periods. The authors call for longitudinal field monitoring of tropical institutional buildings integrating PCMs with night ventilation, research into bio-based phase change materials from local resources, and future systematic reviews with registered protocols, full database coverage, and formal quality appraisal. The overall message is that thermal mass and natural ventilation function best as a synergistic, context-dependent pair, a strategy whose benefits are real but whose magnitude depends heavily on climate, humidity, building type, and the discipline of the nightly purge.

Subject of Research: Integration of thermal mass and natural ventilation for passive cooling in tropical institutional buildings

Article Title: Thermal mass and natural ventilation integration for passive cooling in tropical institutional buildings: a systematic literature review

Article References: Sholanke, A. B., & Agbetoye, D. (2026). Thermal mass and natural ventilation integration for passive cooling in tropical institutional buildings: a systematic literature review. Frontiers in Energy Research, 14, Article 1974826. https://doi.org/10.3389/fenrg.2026.1974826

Image Credits: AI Generated

DOI: 10.3389/fenrg.2026.1974826

Keywords: thermal mass, natural ventilation, passive cooling, tropical climate, institutional buildings, night flushing, phase change materials, systematic review, building energy efficiency, sustainable architecture, solar chimney, thermal comfort

Urban and Calder’s extensive research is revolutionary in its approach: for the first time, they have quantified the energy inputs associated with a diverse array of historic architectural marvels. By calculating the embodied energy—the total energy consumed in the construction and operation phases—acrosscivilizations and epochs, they draw a striking correlation between types of fuel and architectural form. Their analysis reveals how energy sources, ranging from human labour and biomass to the advent of fossil fuels, have dictated not only construction techniques but also the spatial and structural decisions that define iconic buildings.

Contrary to popular belief that modern buildings are inherently more efficient, the study underscores a paradox: buildings from the fossil fuel era tend to consume vastly more energy both in their manufacture and operation than their ancient counterparts. The architectural transformation that began in the 17th century, propelled by the rise of affordable fossil fuels, led to an intensive reliance on materials and production processes with steep energy demands. This shift inverted previous norms, where human labour was relatively inexpensive, and heat was a scarce commodity, giving rise to energy-intensive construction that marginalizes manual craftsmanship in favor of mechanized efficiency.

The consequences of this historic pivot are profound. The authors describe today’s architecture as “fundamentally an architecture of intense fossil fuel consumption,” highlighting that even minimalist designs touted for their simplicity often harbor insidious energy footprints. A glaring example is the Seagram Building in New York City, famous for its clean lines and minimalist aesthetic. Despite its celebrated design, it scored a mere 3 out of 100 on the U.S. Environmental Protection Agency’s energy efficiency rating. Astonishingly, the energy required for its construction alone exceeded the total energy outlay needed to quarry, transport, and assemble 5.5 million tonnes of stone for the Great Pyramid of Giza.

This startling revelation reframes the iconic modernist motto “less is more.” Urban and Calder argue it should instead read “less is more carbon,” emphasizing the concealed environmental toll behind ostensibly sparse designs. When normalized per square meter of floor space, the Seagram Building consumed four times more energy than the average American office building in 2012. This uncovers an often overlooked dimension: architectural minimalism does not automatically equate to sustainability, especially when lifecycle energy consumption is taken into account.

In stark contrast, traditional architectures such as the Scottish blackhouse exemplify how passive design and locally sourced materials can achieve exceptional thermal efficiency. These ancient structures relied on intricate knowledge of climate, material properties, and spatial layout to provide durable, comfortable living environments without dependence on fossil fuels or intensive mechanization. This juxtaposition highlights a critical insight: centuries-old vernacular designs hold valuable lessons for contemporary sustainable architecture, particularly in delivering comfort and functionality alongside ecological responsibility.

Urban and Calder’s analysis spans an impressive 4,500 years of architectural history, from the monumental Great Pyramid to the ultra-modern Kuala Lumpur International Airport. Their meticulous breakdown of energy consumption encompasses the entire lifecycle of building materials—mining, processing, transport, assembly, maintenance, and eventual disposal or recycling. This holistic view challenges simplistic sustainability metrics that often focus on operational energy alone, ignoring the significant embodied energy that determines a building’s true environmental impact.

One of the most consequential findings regards the materiality of construction. The authors demonstrate that structural stone tenements require substantially less energy over their lifecycle compared to their brick equivalents. This insight is pivotal for architects and policymakers aiming to reduce carbon footprints pragmatically, as it provides concrete data favoring the use of certain materials over others. By understanding precise energy costs, the industry can move beyond abstract sustainability claims toward quantifiable strategies that mitigate environmental damage.

Professor Florian Urban eloquently asserts that “with regard to energy consumption, the world has never had so many pharaohs.” His metaphor highlights a contemporary irony: ordinary buildings today consume more energy than the most extraordinary structures of the ancient world. This sovereignty of energy use underscores an urgent need to reconsider fundamental architectural paradigms as the construction sector accounts for a staggering 37% of anthropogenic climate emissions.

The call to action embedded in Form Follows Fuel disrupts prevailing orthodoxies about sustainable architecture. It challenges the assumption that technological advancement alone can resolve the climate crisis in the built environment. Instead, by revisiting and adapting principles derived from pre-fossil fuel architectures, designers could develop buildings that operate within the ecological limits of the planet while satisfying modern functional requirements. The authors articulate a vision where sustainability is rooted in systemic energy understanding rather than mere innovation fetishism.

Further, the book poignantly reflects on societal perceptions of sustainability. The authors note that pre-industrial living conditions often appear impoverished when viewed through the lens of energy-rich modernity. Yet, these conditions boasted a critical advantage: they utilized resources at a rate the planet’s ecosystem could sustain. This perspective compels current societies to reconcile their desire for comfort and convenience with the finite nature of energy and material resources, emphasizing resilience and circularity in architectural practices.

Given the building sector’s outsized role in driving climate change, the insights from Urban and Calder provide both a diagnostic and a prescriptive lens. Their research equips architects with rigorous, quantitative tools to dissect energy demands across building components and suggests practical shifts in material choice, design methodology, and energy strategy. By integrating lessons rooted in history and low-tech ingenuity, the discipline could pivot towards truly sustainable futures.

As architects, engineers, and policymakers grapple with the complexities of achieving net-zero emissions, this work underscores the necessity of a paradigm shift. Rather than defaulting to high-tech fixes, the built environment must learn from its history to embrace low-carbon architecture that is informed by empirical evidence, respects ecological boundaries, and ultimately reduces humanity’s carbon legacy.

Subject of Research: Energy consumption and sustainability in historical and contemporary architecture
Article Title: Revisiting Ancient Wisdom: How Energy Shaped Architecture and Can Guide Sustainable Design
News Publication Date: Not specified
Web References: http://dx.doi.org/10.4324/9781032637174
References: Urban, Florian and Calder, Barnabas. Form Follows Fuel: 14 Buildings from Antiquity to the Oil Age, Routledge
Keywords: Natural resources conservation, Climate change, Environmentalism, Architectural design, Building construction, Ancient architecture, Structural engineering, Climate change mitigation