Abstract
As climate change intensifies the threat of overheating in residential buildings, particularly in vulnerable council housing, traditional simulation tools fall short in adaptability and real-time performance. This article outlines a transformative, data-driven approach using machine learning (ML) to assess and mitigate summer overheating. Drawing from a London council housing study and a 1920s flat case study, we explore supervised, unsupervised, and reinforcement learning methods to enhance predictive accuracy, automate retrofit decisions, and improve occupant comfort. By merging architectural simulation with ML, we pave the way toward intelligent, climate-resilient, and equitable design strategies.
1. Introduction: Climate Change and Overheating in Urban Housing
Overheating in residential buildings has emerged as a pressing issue in the face of rising temperatures and urban densification. Council housing, often occupied by vulnerable populations, is particularly at risk due to outdated designs, limited ventilation options, and poor insulation. A recent study of London council homes revealed that overheating occurs in a significant proportion of purpose-built and converted flats—particularly those constructed pre-1919 or post-2000—and is exacerbated by urban heat islands, poor ventilation, and high occupancy levels.
Traditional thermal comfort models such as PMV-PPD and adaptive approaches often fail in real-world scenarios, with accuracies as low as 34%. Machine learning offers a new paradigm—one that learns from complex datasets, evolves with changing conditions, and supports intelligent intervention strategies.
2. Key Factors in Overheating Risk
Based on the London study and council housing analysis, several contributing factors were identified:
Urban Heat Island Effect:
- Up to 2°C warmer in dense urban regions
- Amplifies nighttime temperatures preventing cooling recovery
- Particularly impacts top floor apartments in high-density areas
Building Typology:
- Purpose-built and converted flats account for the majority of overheating cases
- Single-aspect dwellings show 27% higher overheating frequency
- Corner units with multiple exposures offer better resilience
Construction Method:
- Insulated cavity walls in framed buildings overheat more than solid, uninsulated ones
- High thermal mass without night purging exacerbates heat retention
- Post-2000 apartments with high insulation show 32% increased risk
Ventilation:
- Natural ventilation alone was insufficient in 42 overheated dwellings
- Security concerns often prevent window opening in ground-floor units
- Mechanical ventilation effectiveness varies by system type and maintenance
Occupant Demographics:
- Higher occupancy rates and vulnerable occupants increase risk
- Elderly residents (65+) face 41% higher heat-related health impacts
- Lower socioeconomic groups have limited adaptation resources
ML can integrate these multifaceted data points to model, predict, and prevent overheating more holistically than static simulations.
3. Machine Learning Use Cases in Architecture
3.1 Predictive Modeling of Indoor Temperatures
Supervised learning algorithms (e.g., Random Forest, XGBoost) trained on in-situ sensor data and building characteristics can predict overheating likelihoods such as:
Temperature Forecasting: Indoor temperature prediction models can identify when spaces will exceed 26°C with 92% accuracy using gradient boosting algorithms. These systems generate hourly temperature forecasts up to 72 hours in advance, offering crucial preparation time for facility managers. Advanced implementations provide spatial temperature mapping across multi-room dwellings, revealing how heat flows and accumulates throughout different zones of a building.
Thermal Comfort Assessment: ML models quantify daily discomfort hours based on industry-standard TM59 metrics, providing objective measures of overheating severity. They generate Predicted Mean Vote (PMV) indices specifically calibrated for vulnerable populations, accounting for how elderly residents experience thermal stress differently. The most sophisticated systems implement adaptive comfort thresholds that continually adjust to occupant feedback, creating personalized comfort parameters that evolve over time.
Cooling Strategy Optimization: Machine learning excels at comparative analysis between passive and active cooling strategies, identifying which interventions will be most effective for specific building configurations. Cost-benefit analysis of various intervention combinations helps maximize limited retrofit budgets. Energy consumption predictions for different cooling scenarios enable managers to balance comfort needs against sustainability goals, particularly during peak demand periods when grid stresses are highest.
These models outperform simulation by continuously updating with live data and historical performance.
4.2 Classification Models for Risk Assessment
ML classifiers can categorize homes by overheating risk using:
Building Characteristics: Classification algorithms incorporate foundational data about building type, materials, and orientation to identify inherent vulnerabilities. Window-to-wall ratio and glazing specifications are particularly significant predictors, with south-facing single-glazed units showing the highest risk factors. The age and retrofit history of properties provide crucial context, as certain construction periods (particularly pre-1919 and post-2000) exhibit distinct overheating patterns due to their characteristic materials and construction methods.
Environmental Factors: ML models integrate weather forecasts and solar radiation exposure data to contextualize building performance within its specific microclimate. They capture microclimate variations specific to urban localities—often missed by regional weather models—such as street canyon effects and proximity to large heat-absorbing surfaces. Seasonal analysis reveals probability patterns of overheating throughout the year, identifying vulnerable transition periods when building systems might be unprepared for sudden temperature changes.
Usage Patterns: Advanced classification systems analyze occupant behavior and ventilation patterns to identify how human factors contribute to thermal performance. Appliance usage patterns and resulting internal heat gains can significantly impact overheating risk, particularly in smaller dwellings. Daily occupancy schedules and density information reveal peak usage periods when combined metabolic heat and activity patterns may exacerbate already challenging thermal conditions, especially in overcrowded council housing units.
These models enable prioritization of retrofitting resources and help identify vulnerable populations.
5. ML-Driven Mitigation Strategies
5.1 Optimized Retrofit Strategy Design
Reinforcement learning and optimization algorithms offer powerful tools for evaluating retrofit options in council housing. These ML approaches can determine the best insulation thickness and material combinations specific to each building type, accounting for factors such as wall construction, thermal bridging, and existing moisture conditions. Window glazing solutions can be optimized based on orientation and g-value parameters, allowing for customized recommendations that balance solar heat gain reduction with daylight admittance requirements.
Cost-efficient retrofit packages can be developed through ML algorithms that consider climate zone parameters, building age, and occupant patterns. These models analyze thousands of possible combinations to identify optimal intervention sets that maximize impact while minimizing costs. ML can also simulate retrofit ROI with remarkable accuracy, factoring in upfront installation costs, projected energy savings over time, and quantifiable improvements in occupant comfort levels.
5.2 Passive Cooling Optimization
Generative algorithms and simulation-trained ML models transform passive cooling design from intuitive practice to evidence-based science. These advanced systems can generate and test thousands of shading configurations within minutes, analyzing performance across different seasons and sun angles. The optimal configurations balance cooling performance with other critical factors like daylight access and views.
ML models excel at predicting optimal airflow patterns via window opening schedules, taking into account wind direction, building geometry, and internal heat loads. By simulating complex fluid dynamics at relatively low computational cost, these tools enable architects to make informed decisions about ventilation strategies. Perhaps most significantly, ML approaches can dynamically balance solar protection with daylight and airflow needs, creating integrated solutions that adapt to changing environmental conditions throughout the day and across seasons.
6. Case Study: 5 Town End House, London
Using data from a MSc dissertation, this 1920s council flat serves as a prototype for ML-based analysis:
Building Characteristics: This case study examined a 1920s purpose-built council flat located in North London, typical of the UK's aging social housing stock. The structure featured solid brick walls with poor insulation (U-value: 2.1 W/m²K), contributing significantly to heat transmission during hot weather. Large single-glazed windows comprising approximately 35% of the façade area allowed excessive solar gain during summer months while providing minimal thermal resistance against heat transfer.
Data Collection Infrastructure: The research team installed temperature sensors in all rooms capturing data at 10-minute intervals, providing high-resolution thermal mapping throughout the dwelling over a six-month period. Detailed analysis of EPC ratings and envelope thermal properties provided baseline performance metrics and identified critical thermal weaknesses in the building fabric. Comprehensive appliance audits identified internal heat gain sources and their contribution patterns to overall thermal load, revealing that cooking activities and older appliances created significant hotspots during peak hours.
ML Pipeline Implementation: The research implemented a multi-output regression model predicting room-wise temperatures with remarkable accuracy (R² = 0.87), capturing complex thermal dynamics between interconnected spaces. This end-to-end ML approach demonstrates the tangible benefits of integrating AI into real-world retrofitting efforts, identifying optimal interventions that reduced projected overheating hours by 76% in future climate scenarios.
7. Conclusion: A Smart, Resilient Future for Council Housing
Machine learning represents a transformative approach to addressing overheating in council housing, enabling a leap from reactive to proactive building design. By integrating ML across multiple domains:
Assessment & Prediction: Machine learning techniques are revolutionizing thermal risk identification by more accurately identifying at-risk properties based on comprehensive analysis of building characteristics. These technologies enable forecasting of building-specific thermal performance under various future climate scenarios rather than generic projections. Perhaps most critically, they can predict overheating events days or even weeks before they impact vulnerable occupants, allowing for proactive rather than reactive intervention strategies.
Design & Mitigation: The power of data-driven modeling lies in developing tailored intervention strategies for different building typologies, recognizing that standardized approaches often fail to address unique architectural characteristics. ML simulations optimize passive cooling design elements through exhaustive virtual testing of configurations impossible to evaluate manually. Cost considerations are central to public housing, where ML excels at creating cost-effective retrofit packages that balance performance improvements with affordability constraints.
Monitoring & Adaptation: The implementation of ML-enhanced control systems transforms buildings from static structures into responsive environments that adapt to changing conditions. These systems can automatically regulate ventilation strategies based on predicted conditions and historical performance patterns. When paired with IoT infrastructure, machine learning creates comprehensive thermal management networks that continuously improve through ongoing data collection and analysis, leading to increasingly precise interventions over time.
As heatwaves become more frequent and intense, integrating ML into the architecture workflow isn't just innovative—it's necessary. This convergence of data science and design creates a pathway toward equitable, adaptive, and resilient housing for a warming world, ensuring that our most vulnerable populations are protected from the growing threat of climate-induced thermal stress.
References
- Wang, Z., Hong, T., & Piette, M. A. (2023). "Data-driven predictive control for building thermal comfort and energy efficiency: A review." Applied Energy, 285, 116380.
- Peng, Y., Nagy, Z., & Schlüter, A. (2022). "Machine learning in architectural design: Current state of the art and future potential." Automation in Construction, 133, 103865.
- Seyedzadeh, S., Rahimian, F. P., Glesk, I., & Roper, M. (2022). "Machine learning for estimation of building energy consumption and performance: A review." Visualization in Engineering, 6(1), 5.
- Gao, N., Shao, W., & Rahaman, M. S. (2023). "Machine Learning Applications in Building Energy Systems: A Comprehensive Review." Energy and Buildings, 275, 112136.
- Tuohy, P. G., & Murphy, G. B. (2023). "Using machine learning techniques to identify retrofit solutions for residential buildings: A case study of UK social housing." Journal of Building Performance Simulation, 14(2), 142-159.
- Ramallo-González, A. P., & Coley, D. A. (2022). "Using self-adaptive optimization in genetic algorithms for building thermal design." Building and Environment, 109, 387-398.