Papers by Gian Luca Brunetti
Energy and Buildings, 2025
This article examines the English-language book literature on passive solar greenhouses (PSGs) − ... more This article examines the English-language book literature on passive solar greenhouses (PSGs) − greenhouses heated by solar radiation with no active energy input. It considers both attached/building-integrated and freestanding agricultural types, and is based on the hypothesis that book literature plays a central role in shaping professional practice. The analysis includes both literature explicitly dedicated to PSGs and building design books containing substantial related content.
The study identifies a significant structural gap in the transmission of PSG-related knowledge into contemporary practice. To demonstrate this, it uses both content analysis and statistical elaboration of the subjects covered by the sources. While the 1970 s and 1980 s saw a surge in PSG publications, recent books on the topic are rare, and many existing ones do not reflect technological advances in building components, energy systems, and design standards of PSGs − especially those following the rise of superinsulated buildings. This literary landscape corresponds to a substantial lack of PSG adoption in Western agricultural practices corresponds, in stark contrast to their widespread implementation in China’s agricultural sector.
This situation appears to be linked to cultural factors shaped by broad, long-term policy actions. Within this framework, book availability can be seen both as consequence and cause, forming a reinforcing feedback loop. The scarcity of updated book literature risks hindering the adoption of PSGs in the West and may misguide developments in emerging domains such as vertical farming (crop-growing facilities developed in height), rooftop greenhouses, and other urban systems integrating green matter into indoor environments.
Architectural Science Review, 2025
Download link: https://www.tandfonline.com/eprint/A7KQTYZKTYYDBN7MD44C/full?target=10.1080/000386... more Download link: https://www.tandfonline.com/eprint/A7KQTYZKTYYDBN7MD44C/full?target=10.1080/00038628.2025.2529339
ABSTRACT: Cold-roof finishes and ventilated roofs are widely recognized solutions for mitigating overheating, and their combination offers the potential for enhanced performance. A notable variation of this approach, seen in high-end architectural projects in hot climates, features high-albedo corrugated metal roof canopies positioned above solid flat roofs, creating a wide ventilated space beneath. This configuration merges the simplicity of flat roofs with an extreme form of the attic configuration to effectively dissipate solar heat gain. This study hypothesizes that increasing the number of ventilated thermal barriers beyond one can further improve heat dissipation. To test this hypothesis, the thermal performance of an experimental double- ventilated-cavity roof was evaluated in a school in Mali through monitoring and environmental simulations, complemented by parametric analyses. The results demonstrate that the double- ventilated-cavity roof outperforms conventional single-cavity designs, achieving lower indoor temperatures and greater resilience to the ageing of roof cover materials.
Solar Energy, 2025
In this article, two novel design indicators for solar greenhouses are derived from the solar ape... more In this article, two novel design indicators for solar greenhouses are derived from the solar aperture and the solar fraction. The two so-obtained indicators do not only take into account solar caption, but also thermal losses, and, thanks to this, can predict heat solar gains more effectively than the two indicators from which they have been derived.
The Abstract of the article as published follows:
Preliminary passive solar greenhouse design can be supported by design indicators related to solar access, such as the Solar Aperture (SA) and the Solar Fraction (SF), assuming that net solar heat gains are proportional to net incoming solar radiation. However, since net solar heat gains also depend on thermal losses, SA and SF are effective only for comparing greenhouses with similar shapes and, consequently, similar thermal heat loss profiles. Currently, no design indicator exists that combines SA or SF with thermal loss considerations. To address this gap, this study introduces two new design indicators: the Passive Solar Performance Ratio (PSPR) and the Solar Gain-Loss Ratio (SGLR). These indicators integrate solar gains and thermal losses, enabling their application to a broader range of greenhouse shapes and design scenarios. Benchmarking the PSPR and SGLR against transient simulation results revealed their superior effectiveness in ranking design options by expected net solar heat gains compared to SA and SF. Replacing SA and SF with PSPR and SGLR in design explorations led to optimal solutions with reductions in degree days and thermal loads for heating and cooling ranging from 3% to 30%. Download link: https://authors.elsevier.com/a/1khPT,tRdWCeB
TECHNE, 2025
This paper provides an overview of the state of the art in vertical farming experiments ... more This paper provides an overview of the state of the art in vertical farming experiments that have explored alterna-tive approaches to the prevailing model, which is currently oriented toward active control of nutrient solutions, microclimatic conditions, and lighting, and is often scarcely aware of urban relations. These experiments propose a natural approach as an alternative to the established model, emphasising the creation of elevated soils, closure of biological cycles, passive climate control, maximisation of natural lighting, and establishing relations with the surrounding context. This approach offers significant functional advantages over the prevailing model, including a reduction in overall environmental impacts and the rate of pathogens affecting plants.
Building Simulation, 2020
The ability to take into account reflections from obstructions is of fundamental importance in bu... more The ability to take into account reflections from obstructions is of fundamental importance in building energy simulation (BES), because reflections can have a substantial influence on solar gains. In BES tools, this ability is often implemented duplicating functionalities that have already been solved efficiently in lighting simulation tools. This happens because importing those functionalities from a lighting simulation tool (source) into a BES tool (target) is usually a complex operation producing non-portable results. This article demonstrates that this ability can be imported modularly and portably without intervening in the internals of the two tools. This can be obtained by: (1) creating, in the source tool, pairs of models which are analogue-on the one hand-to the original model in the target tool, and-on the other hand-to the model in the target tool hypothetically enriched with some predictive ability only available in the source tool; (2) measuring, at each time step, the ratio between the performances predicted by the source tool as regards the two analogue models; (3) re-scaling, at each time-step, the performance predicted by the target tool on the basis of that ratio. When appropriate analogue models are utilized, this strategy enables distinct simulation tools to work like an integrated computing unit.
Journal of Building Performance Simulation, 2020
Building performance simulation can support parametric explorations of design option spaces. Reso... more Building performance simulation can support parametric explorations of design option spaces. Resources available for modelling and computing often require the reduction of the descriptive information of a design solution at the level of design-space model rather than at that of building model. To obtain that reduction, two design-space models of different scope (for example, one full-scope and simplified, the other partial-scope and detailed) can be combined to make their responses usable as surrogates of those produced by a full-scope detailed inquiry. But aligning two building models of different scope can be difficult and sometimes impossible. This article presents a design-space 'grafting' technique supported by metamodelling that makes possible to hybridize two non-aligned design-space models so as to obtain a diffusely calibrated conjoint response. The strategy can be integrated into metamodelling and decomposition-based optimization to decrease the information costs entailed by parametric explorations.
Journal of Building Performance Simulation, 2020
This paper introduces a technique for reducing the sampling size necessary to explore a design sp... more This paper introduces a technique for reducing the sampling size necessary to explore a design space via building performance simulation. The strategy is based on a novel algorithmic procedure for creating a metamodel from an incomplete data series of a multivariate design problem. The algorithm interpolates the near-neighbours of the unknown vectors in a design space by the means of the near-neighbouring gradients, and progressively creates a global network of local relations involving vectors and gradients. The procedure produces low deviations with respect to the fully simulated series and performs at its best with sparse clusters of adjacent vectors (of the kind produced by star samplings or block-coordinate searches), unsmooth performance landscapes, and small sampling densities. The technique can also be utilized advantageously in optimization: post-metamodelling on the basis of the samples taken in an optimization search can indeed increase both the breadth of the information produced and the optimization efficiency.
TECHNE, 2023
This paper analyses the evolutionary trends in the application of artificial intelligence (AI) in... more This paper analyses the evolutionary trends in the application of artificial intelligence (AI) in building design, focusing on: a) the decline of knowledge-based expert systems and the rise of systems integrating heuristic and stochastic approaches; b) the increasing use of evolutionary algorithms for optimisation; c) a peak in the influence of probabilistic methods around 2010; and d) the progressive dominance of deep learning since 2012. It is likely that the next significant development will involve the hybridisation of deep learning and symbolic AI, with the contribution of design domain experts in formalising knowledge expected to play a fundamental role in driving this evolution.
Techne. Journal of Technology for Architecture and Environment, 2019
This article explores the possibility of utilizing a game engine to support the description of co... more This article explores the possibility of utilizing a game engine to support the description of construction solutions aimed to self-builders. The results of this experimentation strengthen the hypothesis that game engines would worth to be made a part of the arsenal of resources available to designers for supporting the description of designed objects. In the presented case study, the use of the game engine has allowed the creation of a software application giving users the ability to navigate interactively the construction procedures by choosing the pace of their exploration and their viewpoints during the work phases.
Automation in Construction, 2016
In this article the most fundamental decomposition-based optimization method -block coordinate se... more In this article the most fundamental decomposition-based optimization method -block coordinate search, based on the sequential decomposition of problems in subproblems -and building performance simulation programs are used to reason about a building design process at micro-urban scale and strategies are defined to make the search more efficient. Cyclic overlapping block coordinate search is here considered in its double nature of optimization method and surrogate model (and metaphore) of a sequential design process. Heuristic indicators apt to support the design of search structures suited to that me thod are developed from building-simulation-assisted computational experiments, aimed to choose the form and position of a small building in a plot. Those indicators link the sharing of structure between subspaces ("commonality") to recursive recombination, measured as freshness of the search wake and novelty of the search moves. The aim of these indicators is to measure the relative effectiveness of decomposition-based design moves and create efficient block searches. Implications of a possible use of these indicators in genetic algorithms are also highlighted.
Six Works for Six Architects: Explorations around Invisible Links
Bioclimatic Design for Informal Settlements
Sustainable Urban Development and Globalization, 2017
In this paper, a review of the reasons hindering the use of bioclimatic design principles in info... more In this paper, a review of the reasons hindering the use of bioclimatic design principles in informal settlements is attempted and the perspective of bioclimatic design in those contexts is discussed. Among the main candidate reasons is the habit of mind induced by the belief that informal settlements grow organically, so as to invariably end up being optimized for their functional tasks. Another reason lies in the very nature of bioclimatic design, which is based on integration, that can be perceived as too a “weak” guarantee of perspective features, not very suitable for competing with clear-cut and powerful strategies like active climatic control. A third reason is constituted by the technical challenges which are presently still posed by the environmental simulation of open and intermediate spaces, especially in hot climatic conditions. In this context, some promising research lines related to climatic control and passive cooling are identified in this text. Those approaches are likely to benefit from an integrated blend of practice and theory and may contribute to increase the attractiveness of bioclimatic principles for the rehabilitation of informal settlements.
Conditions for an open-source approach to sustainable architecture (English translation)
TECHNE, 2014
In hot-climate developing contexts, the widespread adoption of profiled metal sheets has driven r... more In hot-climate developing contexts, the widespread adoption of profiled metal sheets has driven radical transformations in roofing systems, often leading to diminished environmental performance. This article examines the thermal behavior of low-cost roofing options for hot climates through computational experiments. These configurations are analyzed and compared to explore practical, cost-effective solutions. The findings underscore the importance of incorporating redundancy in heat-transmission barriers in "cool" roof designs to achieve superior performance at reduced costs. Among the configurations examined, big-size ferrocement tiles ventilated in the hanging-ceiling space emerge as a promising option, particularly suited to regions where wood is scarce.
This paper reports the results of experiences with the use of parallel coordinates plots for the ... more This paper reports the results of experiences with the use of parallel coordinates plots for the analysis of multi-objective, multivariate problems for architectural design at the micro-environmental scale, as possible through the support of thermal and lighting simulation analyses. Parametric analyses applied at the micro-urban level may produce a wealth of information which is difficult to exploit for what both design and decision-taking are concerned. One reason for this is the sheer difficulty of producing convincing visual representations of the complex relations between the most relevant variables in play. Pragmatic strategies for the use of parallel coordinate plots have been experimented by the author to produce pictorially eloquent representations blending quantitative and quantitative information. This was mainly done through three strategies: -texturing, allowing for an increase of understandability of large data domains; -layering, through the superimposition of suitably treated representations of distinct objective functions; -filtering, through the application of threshold levels to objective functions.
TECHNE, 2019
This article presents the results of an experiment testing the feasibility of using a game engine... more This article presents the results of an experiment testing the feasibility of using a game engine integrated into an opensource 3D modeling application-Blender-to describe construction solutions for self-builders and, more broadly, to facilitate assembly processes. In this framework, the game engine component enabled the presentation of assembly operations through an interactive interface, allowing users to explore various aspects of the assembly procedures at their own pace and from chosen viewpoints, synchronized with construction time-steps. The ability to export virtual models as executable files ensures that the resulting games/programs can be used without requiring prior knowledge of the originating software tools or their availability. The reported procedure aligns with an ongoing trend, extending its scope of application. While the use of game engines in architecture has so far been predominantly focused on the interactive virtual exploration of environments and spaces, this work emphasizes their potential for describing and clarifying construction assembly operations.
PLEA 2017 Conference Proceedings, 2017
This paper describes the process followed in designing a low-cost botanical solar greenhouse for ... more This paper describes the process followed in designing a low-cost botanical solar greenhouse for a river park in northern Italy, emphasizing the strategies adopted to ensure robustness under site-specific constraints. The design options were significantly limited by practical factors, including the conditions of the building site, a very tight budget, and the requirement for the greenhouse to be self-built by the design team-comprising six students and two architects (including the author)-within the brief duration (eighty hours) of a building workshop. Furthermore, the decision-making process was structured to be rational, relying on majority voting for each major decision step. The resulting greenhouse demonstrated ease of construction and will serve in the future for assessing the alignment of expected performance-predicted through thermal and lighting simulations-with actual recorded performance. The paper highlights the peculiarities of the decision-making process, shaped by the necessity to optimize within a constrained search space defined by local conditions and the deliberate incorporation of redundancy as a feature to enhance thermal and construction-level robustness. Among the major constraints influencing the decision process, aside from the low-cost requirement, were: the presence of a "C"-shaped uninsulated concrete south-facing wall; solar obstructions from nearby hills and deciduous trees; the need to avoid delays caused by the curing of mortars and concrete; reliance on seasonal manual controls for solar shading devices and ventilation to minimize daily operational demands; and the adoption of construction solutions that could accommodate the limited precision of the builders. .
Sustainable Mediterranean Construction, 2018
This article presents the results of acoustic trials conducted on cladding systems composed of wo... more This article presents the results of acoustic trials conducted on cladding systems composed of wooden planks joined using rigidly bolted steel or wood plate connectors. These connectors are further secured to either heavy steel plates acting as resonators or sand-filled containers functioning as dampers. Both configurations significantly alter the overall acoustic response of the cladding system. This approach enables adjustments to the system's overall mass and compound rigidity, allowing for the tuning of its acoustic performance without modifying its physical layout. The study explores the potential applications of this strategy, particularly in building rehabilitation and re-characterization.
Sustainable Urban Development and Globalization. New strategies for new challenges— with a focus on the Global South, 2018
This paper reviews the challenges impeding the adoption of bioclimatic design principles in infor... more This paper reviews the challenges impeding the adoption of bioclimatic design principles in informal settlements and explores the potential of bioclimatic design in such contexts. One significant obstacle is the relaxed mindset stemming from the belief that informal settlements develop organically and are thus inherently optimized for functionality. Another challenge lies in the intrinsic nature of bioclimatic design, which emphasizes integration-often perceived as a "weaker" approach compared to robust strategies like active climatic control. Additionally, the technical complexities associated with environmental simulations of open and intermediate spaces, particularly in hot climates, further hinder the application of these principles. In this context, promising research avenues related to climatic control and passive cooling are identified. These approaches, which benefit from a synergy of practice and theory, hold potential to enhance the appeal of bioclimatic principles for the rehabilitation of informal settlements.
Uploads
Papers by Gian Luca Brunetti
The study identifies a significant structural gap in the transmission of PSG-related knowledge into contemporary practice. To demonstrate this, it uses both content analysis and statistical elaboration of the subjects covered by the sources. While the 1970 s and 1980 s saw a surge in PSG publications, recent books on the topic are rare, and many existing ones do not reflect technological advances in building components, energy systems, and design standards of PSGs − especially those following the rise of superinsulated buildings. This literary landscape corresponds to a substantial lack of PSG adoption in Western agricultural practices corresponds, in stark contrast to their widespread implementation in China’s agricultural sector.
This situation appears to be linked to cultural factors shaped by broad, long-term policy actions. Within this framework, book availability can be seen both as consequence and cause, forming a reinforcing feedback loop. The scarcity of updated book literature risks hindering the adoption of PSGs in the West and may misguide developments in emerging domains such as vertical farming (crop-growing facilities developed in height), rooftop greenhouses, and other urban systems integrating green matter into indoor environments.
ABSTRACT: Cold-roof finishes and ventilated roofs are widely recognized solutions for mitigating overheating, and their combination offers the potential for enhanced performance. A notable variation of this approach, seen in high-end architectural projects in hot climates, features high-albedo corrugated metal roof canopies positioned above solid flat roofs, creating a wide ventilated space beneath. This configuration merges the simplicity of flat roofs with an extreme form of the attic configuration to effectively dissipate solar heat gain. This study hypothesizes that increasing the number of ventilated thermal barriers beyond one can further improve heat dissipation. To test this hypothesis, the thermal performance of an experimental double- ventilated-cavity roof was evaluated in a school in Mali through monitoring and environmental simulations, complemented by parametric analyses. The results demonstrate that the double- ventilated-cavity roof outperforms conventional single-cavity designs, achieving lower indoor temperatures and greater resilience to the ageing of roof cover materials.
The Abstract of the article as published follows:
Preliminary passive solar greenhouse design can be supported by design indicators related to solar access, such as the Solar Aperture (SA) and the Solar Fraction (SF), assuming that net solar heat gains are proportional to net incoming solar radiation. However, since net solar heat gains also depend on thermal losses, SA and SF are effective only for comparing greenhouses with similar shapes and, consequently, similar thermal heat loss profiles. Currently, no design indicator exists that combines SA or SF with thermal loss considerations. To address this gap, this study introduces two new design indicators: the Passive Solar Performance Ratio (PSPR) and the Solar Gain-Loss Ratio (SGLR). These indicators integrate solar gains and thermal losses, enabling their application to a broader range of greenhouse shapes and design scenarios. Benchmarking the PSPR and SGLR against transient simulation results revealed their superior effectiveness in ranking design options by expected net solar heat gains compared to SA and SF. Replacing SA and SF with PSPR and SGLR in design explorations led to optimal solutions with reductions in degree days and thermal loads for heating and cooling ranging from 3% to 30%. Download link: https://authors.elsevier.com/a/1khPT,tRdWCeB