This year’s UK Passivhaus Conference 2024 was held in Oxford – a city where historic tradition meets cutting-edge research and innovation making it an ideal backdrop for exploring the latest developments in Passivhaus and low-energy design.
Every year the conference brings together passionate designers, contractors, suppliers, and key decision makers from across the UK’s built environment, to explore and critically reflect on the latest Passivhaus advancements and to look ahead at what the built environment needs to do to push forward on our path to Net Zero.
Below are our top takeaways from this year’s conference:
Net Zero Neighbourhoods: Passivhaus is here to help
The main focus of this year’s conference was ‘The role of Passivhaus in net zero neighbourhoods’, so as well as looking at recurring themes of optimising fabric and construction on a building scale, there was a greater emphasis on the macro-scale strategies needed to reduce energy demand and balance peak demand across the UK electrical grid.
There were several presentations showcasing the commitment of local councils to Net Zero neighbourhoods, and how important the Passivhaus standard is for providing certainty in this transition to a Net Zero Future.
Local planning policies are increasingly referencing and adopting the Passivhaus standard as a way of accurately estimating and reducing operational energy. For example, Cambridge Council and York City Council shared insights into their policies:
Michael Jones of York City Council provided an overview of their commitment to net zero neighbourhoods and the Passivhaus design standard by illustrating some of the Passivhaus housing developments which have followed their ‘Building Better Places’ Design Manual approved in 2019. It was reassuring to see York City Council encouraging the use of low carbon natural materials on their developing masterplans, including timber frame with blown cellulose insulation. It was also refreshing see broader aspects of net-zero neighbourhoods being prioritised including investment in high-quality shared green spaces (even community orchards) and sustainable transport options to encourage diversity and multi-generational living across a mix of tenures.
Benedict Binns of Cambridge Council also highlighted their commitment to the Passivhaus standard. As the ‘second largest social housing provider in the country’ they set out in their 2021 Sustainable Housing Design Guide that all council homes must target Passivhaus Certification and, from 2030, should be designed to target Net Zero.
Cambridge Sustainability housing Guide – an example of local policy documents promoting Passivhaus as a way of reaching Net Zero Carbon. Slide from presentation by Benedict Binns of Cambridge Council.
City of York Council – Housing Delivery Aims showing commitment to delivering Certified Passivhaus homes. Slide from presentation by Michael Jones of York City Council.
Perceived vs. Actual uplift in Cost for Passivhaus: Challenge it
Despite the adoption of Passivhaus across many developments, there were references in some presentations to the perceived uplift in cost of Passivhaus which we found to be concerning. The current economic climate is a challenging context for clients and contractors alike to ensure buildings meet the latest Building Regulations, Building Safety Act requirements and sustainability targets whilst also dealing with the supply chain and material market volatility in the economy.
We believe a lot of the uplift in costs is to do with these enhancements and the current volatile condition of the economy. Passivhaus – with its focus on creating certainty throughout the design and construction process – provides a way of reducing risk and providing certainty on projects and therefore the perception that Passivhaus significantly increases costs and increases risk on projects should be challenged and weighed up against the longer term benefits.
More research needs to occur around how contractors and clients are perceiving the quality assurance process that Passivhaus brings to construction. It is this cost that is seeing councils like Cambridge City Council diverging away from the official Passivhaus Standard to introduce new alternative standards such as, Cambridge’s ‘CamStandard’ and ‘CamStandard Plus’.
The question is how is quality assessed in this context: is a parallel methodology employed that mirrors the Passivhaus quality process? This is a lively debate across the Passivhaus community at the moment in projects of all scales. Scotland is also looking at a Scottish Passivhaus equivalent which is more about how the methodology is brought into the existing Scottish review processes which is still out for consultation until the 23rd October. This is a good example of the Passivhaus methodology being adopted more formally given its assured process.
The Passivhaus Trust intends to release a detailed paper on cost development addressing some of these topics in 2025.
UK wide Energy Networks: The need for trading locally-produced energy
Barbara Hammond of Low Carbon Hub shared an excellent insight on the wider topic of electrical grid networks, emphasising the importance of balancing peak demand on a neighbourhood scale as well as reducing demand.
Her presentation highlighted that if the UK doesn’t drastically reduce its energy demand, we will need the electrical infrastructure system to be four times the size that it is currently. If the built environment significantly reduces demand e.g. through adopting Passivhaus as a standard, it would still need to double in size.
It is critical therefore that we deliver highly efficient buildings that produce as much of their own energy demand as possible. But it is also important that we establish efficient energy networks which enable buildings to flexibly trade locally-produced energy when needed so that as little demand as possible is drawn from the grid.
Energy generation and approaches outlined by Barbara Hammond for new build & retrofit.
Image from Barbara Hammond of Low Carbon Hub’s presentation.
National Policy: Progress is on the horizon, but it requires everyone’s input
Whilst many local planning policies appear to be taking positive steps towards achieving net zero, on-going concerns remain around National Regulation. Lewis Knight of Bio Regional highlighted the issues with current Building Regulations being inadequate for meeting the UK’s Carbon Targets, most critically:
Current regulations still exclude unregulated loads such as household equipment which significantly underestimates energy use
Current SAP compliance modelling is not accurate enough and does not reward good building design
The lack of in-use verification of energy demand – energy efficiency should be measured based on in-use energy demand rather than inaccurate predictions.
Lewis outlined a preferred alternative policy approach of adopting ‘Tue Net Zero’ with an EUI-based metric using tools like the PHPP to provide more robust energy predictions, however highlighted that this approach often requires additional justification to the Planning Inspectorate due to it differing from SAP compliance modelling – despite it being more accurate.
Comparison of different policy approaches from presentation by Lewis Knight, Bioregional
Julie Godefroy’s presentation provided confidence that meaningful progress is imminent, with the release of the UK Net Zero Carbon Buildings Standard which was released in ‘Pilot’ form a few days following the conference 24/09/2024.
A huge amount of work has been done by industry stakeholders and Technical Steering Groups (including input from Architype) to develop the standard which finally provides a robust definition for Net Zero Carbon buildings across a range of sectors. The Standard sets limits for Operational Energy as well as reporting requirements for embodied and broader carbon metrics.
Overview of the UK Net Zero Building Standard – it’s success if reliant on all stakeholders in the built environment encouraging the adoption of the Standard and reporting back on our projects. Image from the UK Net Zero Carbon Buildings Standard Overview Document
Operational and Embodied Carbon: The need to prioritise both
Whilst Passivhaus provides the ideal tool for minimising operational carbon, the importance of embodied carbon should never be overlooked.
It was refreshing to hear more dialogue around embodied carbon at the conference this year, although many projects being showcased for their operational performance were far from exemplary when it comes to embodied carbon.
Seb Laan Lomas closed the conference by showcasing the inspiring work and research being done by Architype, illustrating the synergies between low embodied carbon and Passivhaus design and the positive benefits that both have on building occupants.
Architype since the 80s has always perceived both operational and embodied carbon to be critical to good design. However, the slow uptake from the wider industry to measure and report embodied carbon of projects illustrates the need for top-down regulation and policies to really see change on a macro scale.
With the launch of the UK Net Zero Building Standard hopefully reporting of both operational and embodied carbon will become common place, however it needs everyone to take part, encourage the adoption of the standard and contribute data. As Ecological Building Systems aptly put it “Join in the chorus” – let’s work together to drive meaningful change.
Architype examples of low embodied & operational carbon – images and embodied carbon calculations from Hackbridge Primary School – the UK’s first Passivhaus Plus School
Looking Ahead
The conference was an inspiring reminder that Passivhaus has proven itself as a critical tool on our trajectory to Net Zero Neighbourhoods. From large-scale masterplans and estate-wide evaluations to individual retrofits, Architype help provide retrofit and new-build net zero carbon consultancy by applying their EnerPHit and Passivhaus Designer services to help organisations’ deliver their individual route to net zero.
For a free one-hour chat about your zero carbon challenges, please contact: [email protected]
