Passive House retrofit of a historic urban block: integrating energy efficiency with preserving architectural heritage

Project Abstract

This study investigates a pathway to significantly improve energy performance in a historic urban block through a Passive House retrofit framework while maintaining and celebrating architectural heritage. The research integrates passive design principles, high-performance building envelope components, and energy systems optimization to achieve superior comfort, durability, and resilience without compromising historic fabric and urban character. A mixed-methods approach combines archival research, architectural surveys, energy modeling, and stakeholder engagement to develop a retrofit strategy that is technically feasible, economically viable, and culturally sensitive. The objectives are to (a) establish baseline energy performance of the block using calibrated dynamic simulations, (b) identify heritage-compatible retrofit measures that meet Passive House criteria, (c) evaluate embodied energy and carbon implications of proposed interventions, (d) assess thermal comfort, indoor air quality, and acoustic performance for occupants, and (e) develop a transferable retrofit framework including governance, procurement, and maintenance pathways suitable for similar historic urban contexts. The study area comprises a densely built, mixed-use block with century-old typologies, where retrofitting options must address limitations such as irregular facades, listed interiors, limited access for mechanical services, and potential impacts on daylight and street vitality. Key findings demonstrate that a carefully staged envelope upgrade—combining high-performance glazing with sash preservation, enhanced thermal bridging detailing, and airtight envelope joints—can substantially reduce heating demands while preserving exterior silhouettes and interior configurations. The integration of a compact, energy-dense heating and cooling system with modular, low-embodied-energy components minimizes intrusions into historic spaces. Passive strategies, including optimized solar gains through reversible shading devices and night-purge ventilation, complement mechanical systems to meet Passive House thresholds for annual primary energy consumption and peak load reduction. The research reveals trade-offs between preserving original joinery and retrofitting glazings, requiring sensitive framing repairs and light-transmittance restoration to maintain legibility of historic interiors. Economic analysis indicates long-term life-cycle cost advantages despite higher upfront retrofit costs, driven by energy savings, extended building life, and potential incentives for heritage conservation. Risk assessment addresses moisture management, mold prevention, and climate-adaptive strategies in a dense urban setting. A governance model and procurement playbook are developed to guide stakeholders—property owners, conservation authorities, designers, and contractors—through decision-making, risk mitigation, and compliance with conservation guidelines without sacrificing performance outcomes. The resulting framework contributes to existing literature by bridging passive design optimization with heritage conservation pragmatics, offering a replicable methodology for historic blocks facing energy retrofit imperatives. The study also provides policy recommendations for urban regeneration strategies that balance climate action with cultural continuity, establishing benchmarks for future research and implementation in similar global contexts.

Project Overview

What This Project Is About

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A plain-language overview of the topic and what the project investigates.

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The Problem It Addresses

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What problem or gap this project tackles and why it matters to the field or society.

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Objectives of the Project

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1. Understand how a historic urban block can meet modern energy standards without losing its character.
2. Identify cost, technical, and regulatory barriers to retrofitting heritage buildings.
3. Propose design strategies that balance energy efficiency with preservation needs.
4. Develop a simple assessment framework for comparing retrofit options.

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What You Will Do Step by Step

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1. Review basic concepts of Passive House and heritage conservation.
2. Select a representative historic block and gather its existing conditions.
3. Document architectural features to preserve and areas for improvement.
4. Propose retrofit approaches (insulation, glazing, airtightness) compatible with heritage values.
5. Estimate energy savings and costs using simple, transparent methods.
6. Evaluate potential impacts on comfort and indoor environment.
7. Identify regulatory and community considerations.
8. Summarize findings into a practical retrofit plan for the block.

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Expected Outcome

A concise retrofit strategy and evaluation framework that demonstrates how energy efficiency can be improved while maintaining historic character, ready for further development or policy discussion.