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New Format, Same Rigour – Starting September with Coaction

Passivhaus Exam Update

<p><strong>Coaction Training CIC are adopting the new compact PHI Certified Designer Exam in September 2025</strong><br>
<br>
<em>The PHI has updated the Certified Designer exam which will now take 1.5 hours to complete – read on to learn more about our CERTIFIED PASSIVHAUS DESIGNER taught by our network of experienced trainers and the new PHI exam which Coaction is offering in September.</em></p>
<p>Starting in September, the Certified Passive House Designer and Consultant exam will be shortened from 3 hours to 1.5 hours. Despite the reduced duration, the exam will continue to cover all topics outlined in the PHI learning targets, and the certification’s high-quality standards will be maintained. Candidates will still need a minimum score of 50% to pass, that’s 40 points out of 80.</p>
<p>The shorter exam format aims to ease time pressure on students while retaining its technical rigour assessing design understanding.</p>
<p><img src="/uploads/certification.png" alt=""></p>
<p>Instead of 31 questions, the new format will include 12 questions on key Passive House concepts such as windows, U-values, airtightness, PHPP, economics and ventilation. Most questions will be multiple choice, with a few involving calculations. The content has been revised to focus on the most relevant questions and eliminate redundancy.</p>
<p>As before, the second part of the exam will feature three extended questions based on design examples. Students will be provided with plans, sections, and façade drawings that contain typical mistakes. They will be asked to identify accurate statements and recommend suitable components for each scenario.</p>
<p><img src="/uploads/3.png" alt="" title="© Passive House Institute"></p>
<p>The global community of certified Passive House professionals continues to grow worldwide.
Since 2007, over 16,800 Designers and Consultants have been certified, along with more than 10,200 Tradespeople since 2012.</p>
<p><strong>Will you be the next to join them?</strong></p>
<p>Join our Certified Passivhaus Designer course to learn the art of designing high-performance, low-energy buildings with our internationally recognised Certified Passivhaus Designer Course.</p>
<p>Through a blend of live webinars, interactive tutorials, and self-study, you'll gain a deep understanding of the Passivhaus standard, building physics, and the essential elements of designing and detailing the building envelope and services. You'll also be introduced to Passivhaus Planning Package (PHPP) software, completing a
whole PHPP and understanding how to use it effectively to interrogate design.</p>
<p>You will be taught by the UK's leading Passivhaus experts - OUR TRAINERS are all highly-experienced practitioners actively working in the sector, who will share practical insights into best practices and real-world challenges. This
course will teach you how to bring this learning to your projects in addition to thoroughly preparing you for the Certified Passivhaus Designer/Consultant exam.</p>
<p>Live, online teaching sessions with our experienced trainers, plus additional tutorials</p>
<ul>
<li>Ongoing access to all training materials, further resources and case studies on our learning platform for 2 years, to support you in applying your new-found knowledge to your work.</li>
<li>Hard copy training manuals that you can use during the exam.</li>
<li>FREE airtightness tapes to support your practical understanding.</li>
<li>FREE enrolment in the Passivhaus Institute’s Certified Passivhaus Designer exam</li>
<li>Our foundation course Bitesize Low Energy Design is included for FREE to get you up to speed with design essentials (usual cost £398)</li>
<li>FREE access to our Introduction to THERM self-study course (usual cost £180)</li>
<li>Discounts for follow-on training with Coaction, including Passivhaus in Practice and Advanced Retrofit Delivery Courses.</li>
<li>Access to our alumni group on LinkedIn to connect with your peers, ask questions and share best practice.</li>
<li>75 hours CPD</li>
</ul>
<p>See course structure, fees, and dates <a href="https://coaction.org.uk/courses/designer">HERE</a></p>


Are you planning, designing, or undertaking a deep retrofit? Join us to find out how the Coaction Training CIC Retrofit Delivery course could benefit your project.

LIVE Q&A Session - Retrofit Delivery Course - Tuesday 1st July  (1pm - 1:30pm)

<p>What will you learn on Coaction Training CIC's <a href="https://coaction.org.uk/courses/retrofit">RETROFIT DELIVERY</a> course? You are invited to join a 30 minute lunchtime session with our trainers <a href="https://coaction.org.uk/people/sally_godber">SALLY GODBER</a> <a href="https://coaction.org.uk/people/kirsty_maguire"></a>and <a href="https://coaction.org.uk/people/will_south">WILL SOUTH</a> <a href="https://coaction.org.uk/people/will_south"></a>on Tuesday 1 July at 1pm online to hear more - bring your questions!</p>
<h3><strong>Catch up on the recording of our LIVE Q&amp;A session held on 1 July :</strong> <a href="https://youtu.be/-MfWE2Jbr_g">HERE</a></h3>
<p>Gain the knowledge needed to deliver successful deep fabric retrofits on-site and focus on the practical challenges and best practices in retrofit projects.</p>
<p>This advanced-level course is the first of its kind in the UK and has been specifically tailored for contractors and installers, but is also valuable for retrofit coordinators and assessors, and design professionals. Successful retrofits require close collaboration between design and construction, and this course provides the essential knowledge and tools to bridge that gap.</p>
<p>This course teaches us how to manage retrofit risks, reduce unintended consequences and deliver quality retrofit using tried and tested techniques. It follows the PAS2035/2030 process, guidance and principles, which were developed in response to the unintended consequences uncovered by the Solid Wall Insulation BRE study in 2016, and in the Each Home Counts review in 2017.</p>
<p>You'll learn the key elements of delivering deep fabric retrofits, moisture management, airtightness, and more, while tackling the unique challenges of retrofit projects.</p>
<p>Designed and taught by experienced trainers with hands-on retrofit expertise, the course is suited for those with a foundational understanding of Passivhaus, the low-energy, comfort and health standard, which can be obtained by taking our <a href="https://coaction.org.uk/courses/bitesize">BITESIZE LOW ENERGY DESIGN </a>course.</p>
<p><strong>For Contractors:</strong> Retrofits are full of risks but with the right approach it can be managed. Learn how to plan, manage, and execute a successful retrofit ensuring high-quality outcomes.</p>
<p><strong>For Designers, Coordinators, Assessors &amp; Consultants:</strong> Gain insights into assessing buildability, supporting contractors effectively, and understanding the practical implications of your designs.</p>
<h3>Further information and to book your place on an upcoming course visit the <a href="https://coaction.org.uk/courses/retrofit">RETROFIT DELIVERY</a> page.<a href="https://coaction.arlo.co/register?sgid=f6b50e824b7745d7b002f29ad9807460"></a></h3>
<p>What do our past participants say:</p>
<p><em>&quot;The course is technically just what I wanted. A good mix of hypothermal and building physics theory but also plenty of case studies and architectural details to understand the application of the theory.</em></p>
<p><em>The experience of the trainers was second to none. We need to consider retrofit design and specification in a holistic and considered way, taking into account a building's history, constrains and defects.</em></p>
<p><em>The course has complimented my existing retrofit knowledge and has provided a lot of food for thought to challenge our architects to produce more robust retrofit designs. If you have done some pre-existing retrofit such as AECB Carbonlite Retrofit or Passivhaus training and want to extend your retrofit knowledge further this will be a great course for you.&quot;</em></p>
<p><strong>Adam Harper, Housing Development Manager, City of York Council</strong> Retrofit Delivery - Autumn 2024</p>
<p><em>&quot;It's great to learn alongside so many passionate people who are wanting to improve the industry and have open discussion about it. I've learnt more about the risks that designers and architect face. The course has given me the confidence to ask the right questions if I feel the design isn't the most efficient and cost-effective way for the client.&quot;</em></p>
<p><strong>Steve Hall, Manager W T Hall Builders</strong> Retrofit Delivery - Autumn 2024</p>
<p><em>&quot;A greater refresher on building physics and I really enjoyed applying this to the in-depth case study and detailing discussions on risks, benefits, buildability and sequencing whilst hearing about others' experiences and creative solutions. The course has really benefitted me in understanding how to apply EnerPHit principles to the retrofit of our social homes and to be able to talk confidently about risks and considerations to be able to gain buy-in with
colleagues.&quot;</em> <strong>Amy Somerville, Retrofit Programme Manager, Joseph Rowntree Housing Trust</strong> Retrofit Delivery - Jan 2025</p>
<p><em>&quot;The course was a good mix of sound theory and good practice, including strategies which work when things don't turn out quite as planned when the building has been opened up. I fully expect this course will benefit my practice hugely going forward and now feel ready to get back into this sector with a fresh set of knowledge and skills to match my extensive experience.&quot;</em></p>
<p><strong>Stuart Clark, Director - Architect - Passivhaus Designer, Fifteen 10 Architects Ltd</strong> Retrofit Delivery - Jan 2025</p>


The Passivhaus standard delivers comfortable, healthy environments with minimal energy requirements by emphasising quality throughout the design and construction processes. But quality shouldn’t be the preserve of a voluntary standard – it should be for everyone.

Trainer Insights - Passivhaus is mostly about quality!

<h3>Coaction trainer <a href="https://coaction.org.uk/people/liam_mcdonagh-greaves">LIAM MCDONAGH-GREAVES </a>shares his personal experience on the challenges of buying newbuilds and how quality assurance comes as standard with a Passivhaus…</h3>
<p>A friend of mine moved into a brand-new house, built in 2019 by a UK volume housebuilder. Naturally, she hoped that it would be thermally comfortable and healthy, even if nowhere near as energy efficient as a
Passivhaus building. Unfortunately, it was even less energy efficient than it was supposed to be, and more importantly, she experienced significant mould problems at the ceiling to wall junction in all 3 bedrooms and the bathroom soon after moving in. [Figs. 1 and 2]</p>
<p><img src="/uploads/20241110_1112072.jpg" alt="Fig. 1: Mould in a bedroom. This is after significant cleaning, but the extent is obvious." title="Fig. 1: Mould in a bedroom. This is after significant cleaning, but the extent is obvious."></p>
<h6><em>Fig. 1: Mould in a bedroom. This is after significant cleaning, but the extent is obvious.</em></h6>
<p><img src="/uploads/20241110_1111422.jpg" alt="Fig. 2: Mould in bathroom" title="Fig. 2: Mould in bathroom"></p>
<h6><em>Fig. 2: Mould in bathroom</em></h6>
<h3>What were the problems?</h3>
<p>When my WARM colleague and I visited, we found a number of defects:</p>
<ul>
<li>The loft insulation had not been pushed far enough into the eaves. This is likely to have been the primary cause of the mould on the ceilings meeting external walls. [Fig. 3]</li>
</ul>
<p><img src="/uploads/20241112_1919512.jpg" alt="Fig. 3: Bottom layer of insulation at the eaves. Near the top of the image, the black plastic eaves ventilation tray is visible. Below this, in grey, is the inner leaf of blockwork. The insulation should be entirely covering the blockwork, pushed up snug against the eave’s ventilation tray. The blockwork is instead cold, which means water vapour is more likely to condense on it in the room below." title="Fig. 3: Bottom layer of insulation at the eaves. Near the top of the image, the black plastic eaves ventilation tray is visible. Below this, in grey, is the inner leaf of blockwork. The insulation should be entirely covering the blockwork, pushed up snug against the eave’s ventilation tray. The blockwork is instead cold, which means water vapour is more likely to condense on it in the room below."></p>
<h6><em>Fig.3: Bottom layer of insulation at the eaves.</em></h6>
<ul>
<li>The insulation had also not been installed tight against the party wall, leaving an air gap. This is likely to have accounted for the remainder of the mould issues. [Fig. 4 &amp; 5]</li>
</ul>
<p><img src="/uploads/20241112_191934.jpg" alt="Fig. 4: Large gap between the loft insulation and the party wall, resulting in mould growth on the ceiling in the room below." title="Fig. 4: Large gap between the loft insulation and the party wall, resulting in mould growth on the ceiling in the room below."></p>
<h6><em>Fig.4: Large gap between the loft insulation and the party wall</em></h6>
<p><img src="/uploads/20241110_112423.jpg" alt="Fig. 5: Air admittance valve with large gaps around it." title="Fig. 5: Air admittance valve with large gaps around it."></p>
<h6><em>Fig. 5: Air admittance valve with large gaps around it.</em></h6>
<ul>
<li>The duct from the bathroom extract fan to the roof terminal had either fallen off or had not been connected in the first place, so moist air was being exhausted into the loft space. [Fig. 6]</li>
</ul>
<p><img src="/uploads/20241112_192049.jpg" alt="Fig. 6: En-suite extract ductwork not connected to roof terminal. This is careless at best and lazy at worst. " title="Fig. 6: En-suite extract ductwork not connected to roof terminal. This is careless at best and lazy at worst. "></p>
<h6><em>Fig. 6: En-suite extract ductwork not connected to roof terminal.</em></h6>
<ul>
<li>Some of the insulation had not been fully unrolled.</li>
<li>When you stuck your head through the loft hatch, the insulation thickness looked fine. But on further investigation, it got thinner as you got further from the loft hatch. <strong>(This is the construction equivalent of a sandwich with most of the filling pushed to the front edge!)</strong> [Fig. 7]</li>
</ul>
<p><img src="/uploads/sandwich.jpg" alt="Fig. 7: If bad builders made sandwiches." title="Fig. 7: If bad builders made sandwiches."></p>
<h6><em>Fig. 7: If bad builders made sandwiches.</em></h6>
<h3>Warranty provider’s response</h3>
<p>Our friend, not knowing any of the above, had complained about the mould issues several times, but to no avail. She was asked to send photos of the outside of the house and the loft space, but the loft had no lighting or crawl boards, presenting a barrier to providing the requisite documentation. She was told by the warranty provider that the problem was “user error”. Call me Mr. Cynical, but the tactic seems to have been to deny and prevaricate until the complainant gives up.</p>
<h3>Resolution?</h3>
<p>My colleague, Karl Parsons, ultimately wrote a detailed technical report for our friend, which she submitted to the warranty provider. The defects were corrected, and within weeks, the mould issues had vanished. It didn’t take much – just doing the job properly. Most people don’t have mates who are construction professionals to lean on, though, and they shouldn’t have to.</p>
<h3>The solution: better quality assurance</h3>
<p>There are measures in place to guard against such issues at the design stage. For instance, junction details must, in effect, achieve a surface temperature factor (fRsi) of at least 0.75 to minimise the risk of mould growth. But if no-one is checking that the building is constructed according to the design, the quality assurance process falls over. These issues escaped both the housebuilder’s own quality checks and those of Building Control.</p>
<p>When you pay for Passivhaus certification, you are buying top-notch quality assurance, ensuring that you get the building you have paid for.</p>
<h3>We can do better</h3>
<p>If you want to build better discover a proven fabric-first approach to low-energy building with our <a href="https://coaction.org.uk/courses/tradesperson">CONTRACTOR &amp; CERTIFIED PASSIVHAUS TRADESPERSON COURSE</a>, designed for contractors at a supervisory or management level and their supply chains. You'll develop skills to deliver successful Passivhaus builds on-site, whether large or small</p>


Bath University

Cundal

East Ayreshire Council

ECD Architects

Edinburgh Council

Kier

Kingerlee

Royal Borough of Kesington and Chelsea

Southampton City Council

Stride Treglown

Willmott Dixon

Learn from the UK's Passivhaus experts

Practitioner-led Passivhaus training

Proud to be official partners of the Passivhaus Trust.

Training construction professionals to meet the climate emergency.

This course will fundamentally transform your approach to sustainable design, giving you knowledge which can be brought to every one of your projects, no matter the brief. Join our community of Certified Passivhaus Designers and become a catalyst for positive change in the construction industry.

Certified Designer

Certified Passivhaus Designer

Discover a proven fabric-first approach to low-energy building with our Contractor & Certified Passivhaus Tradesperson course, designed for contractors at a supervisory or management level and their supply chains. You'll develop skills to deliver successful Passivhaus builds on-site, whether large or small, and the knowledge to achieve the internationally recognized Passivhaus Tradesperson certificate, backed by UK-specific expertise.

Certified Tradesperson

Contractor & Certified Passivhaus Tradesperson

Exclusive for Coaction Training CIC Alumni and Students!  Join our expert trainers live as they share insights from 12 real-world Certified Passivhaus, deep retrofit, and EnerPHit projects they've worked on. Earn 1 PHI point for every live session you attend!

Trainer Case Studies 2025

Coaction Trainer Case Studies - Webinar Series 2025

This introductory level course explores sustainable construction design through lessons learnt from Passivhaus, offering a quality-assured route to achieving healthy, high performance buildings, with a focus on reducing energy use, while also addressing embodied energy and construction waste.

Bitesize

Bitesize Low Energy Design

Are you a Built Environment Lecturer looking to future-proof your career? Coaction Training CIC is excited to announce a specially discounted Passivhaus Designer summer course open to all UK university students and academics in built environment disciplines!  This course will fundamentally transform your approach to sustainable design, giving you knowledge which can be brought to every one of your projects, no matter the brief. Join our community of Certified Passivhaus Designers and become a catalyst for positive change in the construction industry.

Lecturer Designer Course

Passivhaus Designer for Lecturers

Are you a Built Environment student looking to future-proof your career? Coaction Training CIC is excited to announce a specially discounted Passivhaus Designer summer course open to all UK university students in built environment disciplines!  This course will fundamentally transform your approach to sustainable design, giving you knowledge which can be brought to every one of your projects, no matter the brief. Join our community of Certified Passivhaus Designers and become a catalyst for positive change in the construction industry.

Student Designer Course

Passivhaus Designer for Students

For contractors and building professionals in Cornwall, this in-person training offers a unique opportunity to upskill in low energy construction techniques that play a pivotal role in delivering Passivhaus and other high-performance building standards such as Cornwall Council's Net Zero policy for new homes.

Passivhaus for Contractors

Our new programme Design Performance for Climate Action aims to equip all UK architecture students to tackle the climate emergency.                                

Passivhaus for Universities

Passivhaus in Practice is a hands-on course at BE-ST, Scotland, designed to bridge the gap between design and construction. Using life-size training rigs, it builds the practical skills needed to deliver high-performance, low-energy buildings. The course is accredited by the Passivhaus Trust and is worth 6 PHI credit points towards certification renewal.

Practical

Passivhaus in Practice

Gain the knowledge needed to deliver successful deep fabric retrofits on-site to PAS 2035. This course focuses on the practical challenges and best practices in retrofit projects, equipping you to manage unforeseen changes and ensure quality.

Retrofit Delivery

Learn how to use THERM software to understand 2D thermal bridges and generate Psi-values, through this self-study course worth 16 PHI Credit Points, which can be completed at your own pace.

THERM

Introduction to THERM

The course was fantastic in bringing together so many different experts from different disciplines - demonstrating the collaboration that is required to design and build a Passivhaus.

I would to say that the course was excellent, and very well presented by the team of tutors.

Online training was great. Very informative and there was plenty of opportunities to ask questions.

Architectural Technician

Carl Roland

Testimonial - Certified Passivhaus Tradesperson Course

<p>&quot;I feel much more technically prepared to detail and inspect the next low energy or Passivhaus project that lands on my desk in the future.&quot;</p>


Manager

Steve Hall

Testimonial - Retrofit Delivery

<p>I've learnt more about the risks that designers and architect face. The course has given me the confidence to ask the right questions if I feel the design isn't the most efficient and cost-effective way for the client.</p>


Senior Designer

Michael Johnston

<p>This Passive House course has been incredibly beneficial in advancing both my technical skills and my career in sustainable building design.</p>


Learn from the UK's Passivhaus experts

Practitioner-led Passivhaus training

Proud to be official partners of the Passivhaus Trust.

Training construction professionals to meet the climate emergency.

Popular Passivhaus courses

Certified Passivhaus Designer

Contractor & Certified Passivhaus Tradesperson

Bitesize Low Energy Design

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Passivhaus Exam Update

LIVE Q&A Session - Retrofit Delivery Course - Tuesday 1st July (1pm - 1:30pm)

Trainer Insights - Passivhaus is mostly about quality!

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