Experimental evaluation of the impact of roofing materials and natural ventilation on attic overheating in a temperate Chilean climate

Arias-Jiménez, N.; Trebilcock-Kelly, M.; Figueroa-SanMartín, R. and González-Cáceres, A. (2026) Experimental evaluation of the impact of roofing materials and natural ventilation on attic overheating in a temperate Chilean climate. Building Research & Information, 54(5), pp. 573-587. ISSN 0961-3218

Abstract

This study presents an experimental evaluation of overheating in habitable attics, examining the combined impact of roofing material and natural ventilation in a temperate climate. 1:5 scale test cells were built in Concepción, Chile (Csb), representative of lightweight housing construction. Asphalt-shingle and Aluzinc (high-reflectance) roofs were compared under two conditions: closed windows and cross-ventilation. Indoor air temperatures were monitored for 15 days in summer and 15 days in winter. Quantitative analysis was carried out using a representative average day for each measurement period. In summer, the test cell with the asphalt-shingle roof reached a maximum temperature of 32.71°C, exceeding that of the Aluzinc test cell by 2.84 K, and exhibited a thermal lag of 2–3 h, maintaining elevated indoor temperatures during the afternoon and delaying night-time cooling. In winter, the differences between materials were considerably smaller (0.84 K), indicating a limited thermal penalty of high-reflectance roofs under low solar radiation. The results confirm that high-reflectance roofs combined with natural ventilation constitute an effective passive strategy for mitigating overheating in habitable attics. This study broadens the regional empirical evidence and highlights overheating as an emerging challenge in temperate climates.

Item Type: Article
Uncontrolled Keywords: cool roofs; natural ventilation; overheating; passive cooling; reflectance
Index terms: natural ventilation, ventilation, roofing, residential construction, cool roof, roof, solar radiation, winter, overheating, summer, air temperature, Chile, penalty, strategy, indoor temperature, quantitative analysis, window, evidence
Subjects: thermal systems, air quality, data analysis and analytics, construction integration, management, regulatory law, energy systems, Geography, environmental engineering, evaluation and assessment methods, architectural elements, design practice, climate science, structural engineering, environmental science
Topics: Business Strategy, Engineering Principles, Legal Issues, Sustainability, Design Practice, Geographical Context, Research Practice
Descriptive scope: 4 PCTA

N.B. Descriptive scope is a count of how many of the five facets of empirical research are indicated by the words used in title, abstract and keywords. It is not intended as a judgement on the research; merely a count of the kind of word we would expect to indicate Phenomenon, Concepts, Theoretical framing, Empirical techniques, Analytical techniques. If all five are present, then a code of “5 PCTEA” will indicate this. If you feel the coding for this record is questionable, we welcome discussion around the terms we matched or the way we categorized them. The facet you would expect may not be coded, or a facet may be coded inappropriately. This can also bear on a larger question, of which facets should be treated as defining in construction management research. Please get in touch, and we will look at it. More details here