The Passivhaus Handbook: A Practical Guide to Constructing and Retrofitting Buildings for Ultra-Low Energy Performance
About this book
The Passivhaus Handbook: A Practical Guide to Constructing and Retrofitting Buildings for Ultra-Low Energy Performance Janet Cotterell and Adam Dadeby Green Books, 2012 In an era of rising energy costs, tightening carbon budgets, and growing public awareness of climate change, the question of how to build — and especially how to heat and cool — our buildings has moved from the margins to the center of both professional practice and policy debate. The Passivhaus standard, developed in Germany in the early 1990s by physicist Wolfgang Feist and Professor Bo Adamson, offers one of the most rigorous and thoroughly validated answers yet devised to that question. Rather than adding renewable energy generation to a leaky, inefficient building envelope, Passivhaus takes the opposite approach: it prioritizes getting the fabric of the building so right — so well insulated, so airtight, so free of thermal weak points — that the building requires almost no active heating or cooling at all.
The result is a structure that can maintain comfortable interior temperatures year-round with a fraction of the energy consumed by a conventionally built equivalent. Janet Cotterell and Adam Dadeby are among the United Kingdom's leading practitioners of the Passivhaus standard, and this handbook reflects the depth of their hands-on experience. Their book is pitched at a practical level — it is written for architects, builders, project managers, and self-builders who want not merely to understand what Passivhaus is in theory, but to actually deliver certified projects on real sites with real budgets and real constraints.
The tone throughout is honest and grounded: the authors are as willing to discuss what can go wrong and why as they are to celebrate the performance outcomes that the standard makes possible. The book is organized into two broad parts. The first part addresses the theoretical and contextual foundations of Passivhaus: what the standard is, where it comes from, what it requires, and why those requirements are justified.
Cotterell and Dadeby provide a clear explanation of the building physics that underpin the standard, accessible even to readers without an engineering background. At the core of Passivhaus are five interlocking principles. First, superinsulation: all elements of the building envelope — walls, roof, floors — must achieve very low heat-loss rates, typically requiring insulation thicknesses significantly beyond what conventional construction codes mandate.
Second, the elimination of thermal bridges: every junction in the building envelope where different materials or structural elements meet represents a potential pathway for heat loss; Passivhaus design requires these junctions to be identified and resolved through careful detailing, supported by thermal modeling software. Third, high-performance windows and glazing: triple-glazed units with thermally broken frames are standard; window orientation is carefully optimized to balance solar gain and heat loss. Fourth, rigorous airtightness: conventional buildings leak air through countless gaps and cracks; Passivhaus buildings are constructed with a continuous, tested airtightness layer, verified by a pressurization test (blower-door test) that must achieve no more than 0.6 air changes per hour at 50 pascals of pressure.
Fifth, mechanical ventilation with heat recovery (MVHR): because the building is so airtight, fresh air must be supplied mechanically; an MVHR unit delivers filtered fresh air to living spaces while extracting stale air from kitchens and bathrooms, and crucially recovers 80–95% of the heat from the outgoing air stream, transferring it to the incoming fresh air before it enters the building. The authors give careful attention to the Passivhaus Planning Package (PHPP), the energy modeling software developed by the Passive House Institute in Darmstadt, Germany. Unlike generic building energy simulation tools, PHPP is specifically calibrated to the Passivhaus standard and has been validated against hundreds of monitored buildings, giving it a level of predictive accuracy that standard-issue modeling tools rarely achieve.
Cotterell and Dadeby explain how to use PHPP to test design iterations, model different window configurations and orientations, and verify that a design will meet the certification criteria before any construction begins. A particularly valuable section of the handbook addresses EnerPHit, the Passivhaus Institute's certification standard for retrofit projects. Retrofitting an existing building to full Passivhaus standard is considerably more challenging than designing a new building from the ground up, because the existing structure imposes constraints on insulation thickness, airtightness detailing, and the elimination of thermal bridges.
EnerPHit relaxes the primary energy demand criteria to reflect these constraints while still requiring substantially improved fabric performance, continuous airtightness, and MVHR. The authors draw on their own experience with one of the very few fully certified EnerPHit retrofits completed in the United Kingdom at the time of writing, offering candid insights into the practical difficulties — and the rewards — of this demanding type of project. The book also addresses the question of economics with characteristic pragmatism.
Passivhaus construction typically costs more per square meter than conventional construction — the premium varies considerably depending on procurement method, specification, and market conditions, but the authors discuss how these additional capital costs must be weighed against substantially reduced lifetime energy expenditure, improved comfort and air quality, reduced risk of condensation and moisture damage, and potentially higher market values. They discuss the policy landscape in the United Kingdom, where building regulations have been progressively tightening, and consider how the Passivhaus standard relates to other low-energy frameworks such as the Code for Sustainable Homes and the Zero Carbon Homes initiative. The second half of the handbook is structured as a practical project guide, walking the reader through the typical stages of a Passivhaus project from initial briefing and team assembly through design development, PHPP modeling, specification writing, procurement, on-site construction supervision, airtightness testing, and commissioning of the ventilation system.
Case studies and real-world examples illustrate how design decisions play out in practice. Final chapters address the experience of living in a Passivhaus — the consistent interior temperatures, the quality of the air, the near-total absence of drafts and cold surfaces, and the minimal running costs — as well as the importance of user education in ensuring that occupants understand and correctly operate their ventilation systems. This is the definitive English-language reference for practitioners serious about delivering ultra-low-energy buildings to the Passivhaus standard.