In this episode, we are joined by Attzaz Rashid (Barratt London) and Joel Callow (Beyond Carbon) to talk about Barratt London's move into Passive House.
It was a chance to get into what attracted Barratt to developing this Lo-E homes proposition and how they came to feel confident about committing to deliver certified Passive House apartments, the team effort that's been employed to make it work, and the way this change has brought about a renewed enthusiasm for the job in some of the project's participants.
It's a really interesting exploration of how the rigour and challenges of Passive House has affected Barratt's approach to high-density building, and how the Passive House approach has come to be recognised as advantageous to Barratt, in all sorts of ways.
Finally, the critique of M&E design that's made late on in the episode is not a Barratt critique—as Az makes abundantly clear—this is one founded in Joel’s experience of inheriting issues that require Beyond Carbon’s expertise for their resolution.
Notes from the show
**SOME SELF-PROMOTING CALLS TO ACTION**
We don't actually earn anything from this podcast, and it's quite a lot of work, so we have to promote the day jobs.
**END OF SELF-PROMOTING CALLS TO ACTION**
Is there a collaboration problem in retrofit within the social housing sector? That was the premise for this conversation with Rafe Bertram, an architect and retrofit expert—appearing in a personal capacity—who was very surprised when I posed the question because he's found collaboration to be a strength in the sector, at least in London.
In the end it led to a conversation about what he's learned from the experiences he's had working on retrofits in the social housing sector, in his community, and even doing big flashy Apple stores.
The most interesting bit though is the strategy he's using to reduce the cost of retrofit, with his theory of reactive planning. It's an approach that takes a systematic integrated asset management approach and adds strategic opportunism into the mix in a way that enables him to piggyback essential works, like roof replacement, and use them as a catalyst for getting into a building to do the sustainability stuff that's usually a lower priority.
Notes from the show
More links to articles about green building, favourable finance, and better valuations:
**SOME SELF-PROMOTING CALLS TO ACTION**
We don't actually earn anything from this podcast, and it's quite a lot of work, so we have to promote the day jobs.
**END OF SELF-PROMOTING CALLS TO ACTION**
This episode is all about case study in circularity and a group of people turning waste into useful materials for the built environment. Daniel Dinizo and Charmaine Cu-Unjieng of NaturLoop are bringing a new bio-based product to market that transforms waste coconut husk into a material that's something between MDF and a particle board.
For us, this presented a chance to talk about how sustainable materials are developed, the challenges of bringing them to market and how responsible businesses can approach supply chain development (the big challenge now).
As professionals who work with LCAs, EPDs, and carbon calcs all the time it was refreshing to get into a product that will have an impact that can be accounted for in human terms, as well as the usual economic and environmental terms.
They're also fundraising right now, so here's the pitch from Charmaine.
NaturLoop at the Final Stage of Pre-Seed Funding
"NaturLoop, the Swiss–Philippine climate-tech startup behind Cocoboard, is at the final stage of its pre-seed round. Cocoboard is the first industry-ready fibreboard made entirely from coconut husk waste and natural adhesives—a truly biocircular material. Featured at Interzum Cologne 2025, Cocoboard embodies the shift in construction and furniture toward biocircularity—no longer a trend but the future of materials. Europe’s sustainable furniture market is set to more than double to $42.6 bn by 2032, with consumers paying around 10% more for sustainable products. NaturLoop is closing its round soon, inviting strategic investors to co-build a climate-positive business that reduces deforestation and uplifts poor coconut farmers—making the industry more future-proof."
Notes from the show
**SOME SELF-PROMOTING CALLS TO ACTION**
We don't actually earn anything from this podcast, and it's quite a lot of work, so we have to promote the day jobs.
**END OF SELF-PROMOTING CALLS TO ACTION**
In this episode we are exploring the relationship between financial institutions and the built environment in relation to sustainability, building performance and mitigating climate change with Ian Bhullar and Ronnell Reffell from UK Finance, the UK financial sector's membership organisation.
The episode itself was prompted by a report that UK Finance published in relation to the incoming UK Government's own Warm Homes Plan: Greening Homes, Creating Growth: Unlocking demand for green home finance. Its recommendations will be familiar to anyone who has been working in the green building sector but it's notable because these arguments and demands are being presented by the banks and lenders.
For us this presented an opportunity to find out what the finance sector is actually thinking about how to address the demands of the built environment in relation to climate change and the financial risk that comes with it.
Most importantly, they're serious about the matter—this is not ESG-style fluff, they know they need to draw in expertise from built environment professional and they want to know what people like you think.
Notes from the show
**SOME SELF-PROMOTING CALLS TO ACTION**
We don't actually earn anything from this podcast, and it's quite a lot of work, so we have to promote the day jobs.
**END OF SELF-PROMOTING CALLS TO ACTION**
We're joined by our new friends from Building Atlas, Nick Taylor and Olga Khroustaleva, who join us for a conversation about commercial retrofit—the non-residential kind.
They’ve got a data driven business that Building Atlas helps commercial asset owners to plan pragmatic retrofit pathways for commercial real estate.
This isn’t important just because how how much energy the non-residential sector consumes, it’s also because 70% of non-residential building assets are on course to become stranded assets because of their EPC rating and MEES regulation.
They are simplifying a complex problem into something that’s comprehensible—aggregating experience (and data) to give broad brush stroke direction that useful.
They’ve also published a paperabout retrofit strategy for commercial buildings: The Beauty in Boring Buildings: The Business Case for Retrofit Beyond Flagship Assets.
Notes from the show
**SOME SELF-PROMOTING CALLS TO ACTION**
We don't actually earn anything from this podcast, and it's quite a lot of work, so we have to promote the day jobs.
**END OF SELF-PROMOTING CALLS TO ACTION**
In this episode Rose Card joins us to describes her multilayered and multi textured approach to innovation and research.
It's a conversation about Energy Systems Captapult's experiment in prescribing heating to keep people warm—that's pretty much it, but there was a lot to talk about.
Notes from the show
**SOME SELF-PROMOTING CALLS TO ACTION**
We don't actually earn anything from this, and it's quite a lot of work, so we have to promote the day jobs.
**END OF SELF-PROMOTING CALLS TO ACTION**
In a slight departure from our usual building performance themes joining us for this episode we have Richard Muscat, a man who has experienced the world of investment and tech from a fascinating range of angles and is seeking ways to do things differently.
In essence, we’re looking at the way venture capital and climatetech are organised in ways that aren't conducive to delivering the impact that's promised. We're not just picking on VCs, we're using them as a means of highlighting a bunch of systemic economic issues—chief among them is how unrealistic goals for growth (in its myriad forms) almost always leads to failed impact. Perversely, it's a bug in the impact investment space that's a feature of the broader investment system.
We also get into concepts of degrowth and economic biodiversity.
Good Homes Alliance event
Launch event of our a best practice guide to ‘Water Efficiency and Reuse in Housing’ on Thursday 10 July.
Notes from the show
**SOME SELF-PROMOTING CALLS TO ACTION**
We don't actually earn anything from this, and it's quite a lot of work, so we have to promote the day jobs.
**END OF SELF-PROMOTING CALLS TO ACTION**
In this episode we're talking about Zero Bills Homes, so we welcome back Nigel Banks, this time accompanied by his Octopus colleague Emma Fletcher*.
We're not directly talking Fabric Fifth again but the concept is central to the Octopus zero bills strategy i.e. prioritising decarbonising energy use and reducing the cost of energy use rather than focusing on reducing energy demand through fabric measures. As before, basic fabric standards are required in order to make the proposition financially viable.
As you might imagine, Jeff was keen to dig into the technical and performance side, so Nigel explains what’s going on in the standard and what they know about how well it’s functioning and Emma fills us in on how it's shaping up to evolve into a building standard in its own right.
We're particularly keen because—although we might be sceptical, which we discuss—the action that Octopus is initiating will raise standards and will shape expectations that will influence the whole residential construction sector, and could go some way to catalysing the bridging of the skills gap.
*She, too, works at Octopus Energy—she is not an actual octopus.
Notes from the show
**SOME SELF-PROMOTING CALLS TO ACTION**
We don't actually earn anything from this, and it's quite a lot of work, so we have to promote the day jobs.
**END OF SELF-PROMOTING CALLS TO ACTION**
This episode is all about a retrofit programme gone wrong in Preston and the effort required to fix it.
It's a story that was covered in the pages of Passive House Plus back in 2018 under the headline "Disastrous Preston retrofit scheme remains unresolved" and until recently we thought it remained unresolved.
We're joined by Filipe Amarante and Joanna Curtis to talk about the Preston Retrofit Catastrophe and all the work that National Energy Action has been doing to fix the grotesque damage that was wrought on a community in the 2010s. It's a project that's consumed at least four years and—in truth—will require many more to make good.
It's not a hopeless story though. The work NEA has carried out is full of lessons for anyone who works in retrofit to learn. They've taken a worst case scenario—one so bad it's hard to imagine how you could make it any worse—and developed a remediation programme that mitigates the worst of the situation while laying out a best-practice template for how one should approach place-based retrofit programmes.
They're also hosting a NEA webinar about the programme on 10 June: sign up here.
Notes from the show
**SOME SELF-PROMOTING CALLS TO ACTION**
We don't actually earn anything from this, and it's quite a lot of work, so we have to promote the day jobs.
**END OF SELF-PROMOTING CALLS TO ACTION**
We are joined by Valentina Marincioni (UCL, UKCMB) and returning guest Toby Cambray (Greengauge) to talk about the bane of all buildings: moisture.
Recently, they they’ve produced a simple explainer video about "breathability" in buildings for the UK Centre for Moisture in Buildings. Given Jeff's proclivity for referring to the 'sweatability' of buildings this seemed like a perfect opportunity to have Toby back and meet his colleague Valentina.
We got into the subject of moisture in some depth, discussed the key terms (vapour diffusion, hygroscopicity, and capillary action), why this all matters, what’s important to understand and how it’s easily misunderstood and easily miscommunicated.
We also play the audio from the video.
Notes from the show
**SOME SELF-PROMOTING CALLS TO ACTION**
We don't actually earn anything from this, and it's quite a lot of work, so we have to promote the day jobs.
**END OF SELF-PROMOTING CALLS TO ACTION**
Joining us for this episode are Tom Cox and Sally Sattary co-founders of Decent Energy.
They have a software startup borne of a retrofit experience that did not meet its homeowner expectations, a proprietary software that works to maximise the value of battery storage to improve two key metrics: reducing cost of electricity and reducing the carbon intensity of the energy you do use.
There's a bunch of chat about the potential of decentralised energy management to help people in all sorts of ways, from reducing one's individual impact to helping the grid cope with occasionally, dangerously abundant renewable energy—an issue which costs every household something like £40 per year, just to turn off the generation facility let it overload the grid.
Anyway, there's loads in there. You can find Decent Energy, Tom, and Sally in all the usual places (links below).
Notes from the show
**SOME SELF-PROMOTING CALLS TO ACTION**
We don't actually earn anything from this, and it's quite a lot of work, so we have to promote the day jobs.
**END OF SELF-PROMOTING CALLS TO ACTION**
This episode is a window into the consumer side of domestic retrofit that’s full of lessons for everyone involved in the retrofit sector.
We speak with retrofit influencer Judith Leary Joyce about the experience of undergoing a deep retrofit and learning how to communicate about the subject with normal people. She talks us through her journey from building an extension during the pandemic to getting deep into retrofit and eventually becoming an unlikely retrofit influencer.
Whether you work in a domestic, commercial, or industrial setting the nature and needs of normal people will remain the same, so this is an episode full of lessons and insights for anyone for anyone involved in domestic retrofit about:
- how to speak with normal people
- how to learn how to do better (TLDR: listen to yourself, or get someone to listen to you to check whether you're baffling your customers)
- how to think about their needs and understand their perspectives
- how to inspire them and inform them better prior to a project
She’s also got some fascinating insights about when people are likely to be able or willing to listen to someone talking about building performance and taking on new ideas
Notes from the show
**SOME SELF-PROMOTING CALLS TO ACTION**
We don't actually earn anything from this, and it's quite a lot of work, so we have to promote the day jobs.
**END OF SELF-PROMOTING CALLS TO ACTION**
Returning champions Richard O'Hegarty and Oliver Kinnane join us to discuss a recently co-authored paper: Understanding the embodied carbon credentials of modern methods of construction (MMC).
Get ready for a long meandering discussion that gets into what they learned and what they think about accounting practices for embodied carbon, as well as plenty of chatter about MMC and why we hate the term (but not what it is).
Notes from the show
**SOME SELF-PROMOTING CALLS TO ACTION**
We don't actually earn anything from this, and it's quite a lot of work, so we have to promote the day jobs.
**END OF SELF-PROMOTING CALLS TO ACTION**
For this episode we were joined by Nathan Gambling. For those that are new to him, he's heating engineer of some repute, a renowned educator, and a fellow podcaster.
The episode revolves around the nature of education and learning, the skills gap—specifically focusing on heat pump and retrofit education—and a post that Nathan put up a few weeks ago about an educational experiment he tried out that led to us thinking about the purpose of education.
In essence, the episode is about how people learn and how this should shape our approach to meeting the skills gap. Nathan is a great communicator and you should check his podcast.
Notes from the show
**SOME SELF-PROMOTING CALLS TO ACTION**
We don't actually earn anything from this, and it's quite a lot of work, so we have to promote the day jobs.
**END OF SELF-PROMOTING CALLS TO ACTION**
This time around we're talking about the UK Net Zero Carbon Buildings Standard (UKNZCBS) with three of its architects: Jess Hrivnak (RIBA), Jane Anderson (ConstructionLCA), and Julie Jodefroy (CIBSE).
The UKNZCBS is the first cross-industry standard for net zero carbon-aligned buildings, albeit in a pilot form. The standard has been developed to enable stakeholders to prove whether a building aligns with the UK’s carbon and energy budgets by providing a single, agreed methodology for defining what ‘net zero carbon’ means for buildings in the UK.
This probably won't be the only episode we'll produce on the subject and we'll be watching its progress with great interest.
Notes from the show
**SOME SELF-PROMOTING CALLS TO ACTION**
We don't actually earn anything from this, and it's quite a lot of work, so we have to promote the day jobs.
**END OF SELF-PROMOTING CALLS TO ACTION**
Last year the Royal Institution of Chartered Surveyors (RICS) released its residential retrofit standard. Given that they're one of the construction industry's oldest, largest, and most influential institutions this felt significant.
Importantly, the RICS organisation has a global footprint, so it has the potential to influence good behaviour far and wide. We're also hopeful in light of the success of the RICS Whole Life Carbon Assessment standard. That is in terms of its apparent impact, adoption, and reach.
In order to get into the subject a bit more we invited Paul Bagust (Head of Property Standards), Steven Lees (Senior Specialist - Residential Survey), and Robert Toomey (Senior Public Affairs Officer) to join us to talk about the standard and the impact they want to see it have.
Notes from the show
**SOME SELF-PROMOTING CALLS TO ACTION**
We don't actually earn anything from this, and it's quite a lot of work, so we have to promote the day jobs.
**END OF SELF-PROMOTING CALLS TO ACTION**
Can we address the decarbonisation of homes by focusing on health? That's the mission that Jenny Danson has set for herself in establishing Healthy Homes Hub, and it's a question that manages to subvert Betteridge's Law of headlines, too.
Healthy Homes Hub is a network, built around an online platform, that's dedicated to transforming the way people experience social housing, and its environmental impact, by creating healthier housing environments. Comprising a series of eight dedicated hubs that cover everything from policy and finance, to retrofit and air quality, the platform enable easy access to important information, insights, and thought leadership.
Jenny has over 25 years of experience in social housing, as a supplier and client-side, driving innovation, delivery and improving lives so she knows what she's talking about.
The project was borne of a frustration with seeing time and effort wasted as people across the sector carry out the same kinds of work, repeatedly, starting from scratch when they could share resources and pool experience. In a sector where capacity is in short supply this time could be easily put to better use.
We talk through the challenges faced by the sector and how a focus on people and health can be used to drive us towards delivering on decarbonisation targets, but train our attention on outcomes for the people living in the 'building assets' not just the performance of the fabric and technology that comprises their home.
While it's explicitly aimed at the social housing sector, the platform offers a wealth of information resources and sharing of experience that could be useful far beyond the provision of social housing.
Notes from the show
Those ventilation papers that Jeff mentioned
**SOME SELF-PROMOTING CALLS TO ACTION**
We don't actually earn anything from this, and it's quite a lot of work, so we have to promote the day jobs.
**END OF SELF-PROMOTING CALLS TO ACTION**
Joining us on Zero Ambitions this week is Chris Carus co-founder of Loco Home Retrofit, a Glasgow-based 'emerging one-step shop'.
Loco Home Retrofit is a retrofit operation that's most interesting for its approach to developing a viable retrofit offer, focused on building trust in communities and with its supply chain as a means to catalysing the decarbonisation of our homes (or at least Glasgow's homes).
And now, they're hiring, seeking to fill three positions (below) so if you know of anyone suitable please share the ads:
As much as anything else, we love how they think about the retrofit challenge. Their considered approach to building a proposition and a method is what has really sold us, possibly because it resonates with our UX-focused approach to everything, but mainly because it seems to make sense.
Notes from the show
**SOME SELF-PROMOTING CALLS TO ACTION**
We don't actually earn anything from this, and it's quite a lot of work, so we have to promote the day jobs.
**END OF SELF-PROMOTING CALLS TO ACTION**
The first episode of January 2025 marks the long overdue, first appearance of Jay Stuart, a long-time friend and colleague of Jeff and a firm fixture of the green building scene in Ireland.
Jay joined us to talk about his latest project: Loop Your Spare. It’s a SaaS platform designed to match 'spare' construction materials with projects that need them on other sites before they have a chance to be classified as waste.
It’s a concept that could largely eliminate the concept of waste and minimise the need for recycling in construction by enabling materials to remain in their highest-value states, thus retaining their value and mitigating the need to put them through all of the (ultimately destructive) processes involved in recycling.
While we’re looking to Ireland in this specific case the issues are universal and the solutions should be able to cross borders with relative ease. It’s really an episode about smart thinking, with specific reference to a bunch of the projects Jay has worked on in the past and what’s coming up in the future.
We've wanted to get Jay on for ages because he’s an innovative and unconventional thinker who simplifies complex challenges in accessible and unexpected ways. He’s also massively experienced, having lectured at University College Dublin’s School of Architecture, worked with leading Irish construction businesses like Ecofix and D/RES, and worked as a government advisor to name just a few things.
Also, it’s an episode that continues the conversations from last year’s episodes with Chris Clarke and Don’t Waste Buildings and their calls to do something about egregious construction waste in the UK.
Notes from the show
**SOME SELF-PROMOTING CALLS TO ACTION**
We don't actually earn anything from this, and it's quite a lot of work, so we have to promote the day jobs.
**END OF SELF-PROMOTING CALLS TO ACTION**
What's it like trying to scale a retrofit start-up?
This episode welcomes Max Bloomfield and Alex Whitcroft, two of the folks from VundaHaus, to talk about their product, its ongoing design and development, and their preparations to scale the business as they raise funds from investors.
VundaHaus designs and manufactures a rapid-fit insulation solution for external wall insulation (EWI) of residential homes. It's a a sophisticated off-site, MMC, insulation jigsaw that’s been developed to make the logistics of installation much easier than traditional EWI.
There's more to the story but you can listen to that on the episode.
Notes from the show
**SOME SELF-PROMOTING CALLS TO ACTION**
We don't actually earn anything from this, and it's quite a lot of work, so we have to promote the day jobs.
**END OF SELF-PROMOTING CALLS TO ACTION**