Passive House Retrofit for Historic Urban Fabric: Thermal Comfort, Energy Resilience, and Heritage Conservation

Project Abstract

This study investigates a holistic retrofit strategy for historic urban fabric aimed at achieving Passive House performance while preserving heritage values, focusing on thermal comfort, energy resilience, and conservation ethics. The research addresses the tension between modern energy standards and preservation imperatives by developing an integrative framework that harmonizes envelope enhancement, airtightness, heat recovery ventilation, and low-energy interior microclimates with careful material selection and reversible interventions suitable for listed or culturally significant buildings. Methodologically, the project combines diagnostic surveying, energy modeling, and performance simulation with experimental validation through monitored retrofit pilots in representative urban blocks. A multi-criteria decision analysis guides the selection of retrofit measures that maximize energy savings without compromising architectural integrity, scale, or spatial character. The study advances a bespoke Passive House Envelope Protocol tailored to historic facades, including optimized window retrofit strategies, thermal bridging reduction, and interior insulation approaches that respect original materials, ornamentation, and load-bearing systems. By integrating solar strategy assessments, shading typologies, and microclimate studies, the research demonstrates how climate-responsive design can stabilize indoor thermal conditions across seasonal variations while maintaining ambient daylight and acoustic comfort. The energy performance analysis indicates significant reductions in heating demand, with modeled annual primary energy use aligned to passive house thresholds under varying occupancy patterns and weather scenarios. The resilience component examines performance during grid disturbances, highlighting the role of airtightness, ventilation heat recovery, and on-site generation potential in maintaining habitability and indoor air quality during outages. Heritage conservation considerations are operationalized through a conservation-led design process, documentation of intervention reversibility, compatibility of materials, and staged implementation plans that minimize visual and structural impact on historic fabric. The project contributes a transferable methodological toolkit comprising diagnostic checklists, retrofit typologies, performance metrics, and monitoring protocols that can be adapted to different heritage contexts and urban densities. Case study outcomes reveal a nuanced balance between energy efficiency gains and preservation outcomes, including preserved or enhanced spatial quality, daylight autonomy, and acoustic performance, alongside measurable improvements in indoor thermal satisfaction indices. The research also addresses policy implications, offering guidelines for regulatory pathways that support adaptive reuse and energy retrofits within heritage districts while ensuring compliance with conservation standards. The final deliverables include a set of design briefs, performance dashboards, and an implementation framework to accelerate decision-making for practitioners and stakeholders seeking scalable, reversible, and culturally sensitive Passive House retrofits in historic cities.

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. Identify how to improve comfort in historic buildings without compromising their character.
2. Evaluate energy improvements that reduce running costs and carbon emissions.
3. Develop practical retrofit guidelines that respect heritage conservation needs.
4. Demonstrate how airtightness, insulation, and ventilation affect indoor conditions.
5. Propose assessment methods suitable for small-scale, real-world projects.

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What You Will Do Step by Step

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1. Review existing literature on passive house design and historic conservation.
2. Select a representative historic urban building for case study.
3. Gather data on current performance (thermal comfort, energy use, moisture risk).
4. Model retrofit options using simple energy tools and ethical heritage considerations.
5. Propose a recommended retrofit plan with cost and impact estimates.

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Expected Outcome

A clear retrofit strategy that improves comfort and lowers energy use while preserving historic value, plus a practical checklist for practitioners and a short case study summary.