Partners in Passivhaus: an interview with Coldwells Build


Based in Aberdeenshire, Clare and Ross Booth are the marriage behind Coldwells Build - now one of few certified Passivhaus contractors in Scotland after taking our Passivhaus training. Hear about their story below or read the case study on our website.

What attracted you to join the Low Carbon Learning training?


The COP26 conference in Glasgow was the catalyst for change within our custom home business. It helped us recognise and rethink the problems caused by the residential construction industry and seek a better way to build.


Our primary motivation was to remove the inefficiency and waste of building one-off, bespoke homes and alternatively, create a sustainable, repeatable, future-proofed housing product where people could live comfortably and consciously.


Encounters with influential industry experts and further education lead us to believe that Passivhaus offered the best solution. Although we had some prior knowledge of the world-leading, low-energy building standard, we had never had the opportunity to build a Passivhaus home.   


We decided to take advantage of the various Passivhaus training programmes offered by BE-ST to educate and upskill not only ourselves, but our workforce of joiners and builders. We felt it was important to get the entire team on board to challenge traditional construction methods and promote a shift in workplace culture.


The Passivhaus training received at BE-ST inspired an ambitious new direction for our business. We are now collaborating with Scotland’s leading Passivhaus designer, John Gilbert Architects, to develop a range of modern, prefabricated Passivhaus homes. Each home will include Passivhaus certification as standard and will marry brilliant design and energy efficiency with a hassle-free delivery model.


What were your aims and expectations?


Our aim was to enhance our knowledge and understanding of sustainable construction techniques and innovative products in the hope we could practically apply these in our day-to-day business operations. 

We were also keen to immerse ourselves in all things Passivhaus, including gaining a deeper understanding of the guiding principles and Passivhaus products, ie: insulation, windows, ventilation systems, etc.


How did the learning process work?


Our team attended a series of detailed webinars as part of the Carbon Lite Passivhaus contractor training course.


We then participated in the AECB’s CarbonLite Passivhaus Practical Contractor training at BE-ST. This presented an opportunity to put Passivhaus theory into practice. Our team were trained in the correct technique for taping and sealing a home and witnessed how an airtightness test is carried out. We were also introduced to different Passivhaus products such as passive slabs, windows, insulation and MVHR systems.


After participating in both the Passivhaus theory and practical courses, our team sat their Passivhaus exams.


The training at BE-ST provided us with the qualifications and skills necessary to build to the Passivhaus standard.


How did you or your organisation benefit from this initiative?


The Passivhaus training at BE-ST was a voyage of discovery for our team. It sparked important conversations about how we can do things better as builders. It forced us to re-evaluate what we stand for, our values and what we’re committed to. As a team, we believe:


  • Exceptional, affordable, low-energy housing should be available to everyone, especially with the accelerating cost of utility bills.
  • Today’s new homes should be future proofed to deliver advanced energy performance to meet Scotland’s net zero target by 2045.
  • With construction responsible for 39% of global carbon emissions, we must play a role in the efforts towards the protection of the natural environment for future generations to enjoy.


In striving to consider and address these issues, our business model has evolved to include a range of modern, prefabricated Passivhaus homes. We believe the Passivhaus standard aligns firmly with our directive to change Scotland’s housing for the better.


How did you or your organisation hope to use this knowledge from the training?


By harnessing the power of collaboration with John Gilbert Architects, we are working on a range of modern, prefabricated Passivhaus homes. Each home will include Passivhaus certification as standard.


This has required an enormous amount of joined up thinking. Although still in the early stages, we are proud to be part of a new wave of purpose-driven building companies committed to pursuing a Scotland where all houses are truly energy efficient. Homes which are built for people and the planet.


What did you feel could be improved, enhanced?


We would love to see more Passivhaus courses (theory and practical) at BE-ST to upskill the construction sector and make Scotland a leading player with exportable skills and knowledge.


Written by Clare Booth, Director Coldwells Build.