Connah’s Quay

Net zero social housing delivered for the same capital cost.

Last updated: 18th February 2022

Date uploaded:

Approved for use

Innovation Lead: Chris Brierley

Website:
activebuildingcentre.com/


Edit this story

Summary

Flintshire Borough Council needed help delivering sustainable social housing so it could play its part in fulfilling the commitment made by Welsh government to be net zero by 2050. Its challenge was ensuring that the build costs of this innovative development would be in line with similar traditional developments. It partnered with the Active Building Centre (ABC) to use existing research and insights around sustainable developments. The ABC worked with local architects to assess the designs, and ensure they were as sustainable as possible from the outset. Important changes were made to the site layout, roof layout and choice of energy-saving technologies and materials. Thanks to smarter energy saving, generation and storage, these new houses are expected to be energy positive and can be delivered at a comparative cost to non-net zero developments - setting a blueprint for homes that are healthy, sustainable and affordable to live in and will help prevent residents from falling into fuel poverty.

Innovation type: Energy
Organisation type: Local authority, Social housing provider

Story building blocks:

Story building blocks:

Learn more about this innovation below and use these building blocks to craft your own story to share.

Open allClose all

Project pioneers

Flintshire Borough Council is a local authority in Wales with a mandate from Welsh government to build low or net zero carbon social housing.

The problem

There is a perception that net zero carbon and active energy technologies are too challenging to use on social and affordable housing, because they make the costs across the supply chain prohibitive. This prevents developers from adopting the kind of approaches and technologies at the very start of a build, that could be the most effective at reducing the embodied carbon or operational emissions of these new homes. Instead, developers end up introducing carbon-reducing tactics too late in the process, minimising its impact and making it harder, and potentially more costly, for developers and local authorities to reach net zero targets.

Vision

The net zero social housing at Connah's Quay is establishing a blueprint for sustainable developments that other councils and registered social landlords can learn from. Putting in place the recommended energy-saving measures from the Active Building Centre at the very start of the build will show how it's possible to create new homes that are net zero carbon for operational energy, in a way that is scalable and can unlock value for councils and tenants alike. These new houses are expected to be completed at a comparative cost to traditional builds (current estimates suggest as little as 2% more than current capital costs). They are also expected to deliver financial, health and wellbeing benefits to the residents, and environmental, economic and social benefits locally.

Key Insight

Flintshire Borough Council received a mandate from Welsh government that it would only fund new social homes if they were net zero, in line with its Future Wellbeing of Generations Act 2015. The council did not have sufficient expertise, insight or resource to deliver a net zero carbon development on its own so approached the Active Building Centre (ABC) which was already working on housing projects in Wales and the South West of England. ABC had identified the importance of early engagement and intervention in the RIBA design process, to maximise the opportunity to realise net zero carbon buildings. Together, they set out to identify the best way to deliver 20 new homes at Ffordd Llanarth in Connah's Quay that would be net zero carbon for operational energy.

First step

The ABC worked with the architects right from the start, before the planning application submission. The team conducted an initial review to see how the designs could achieve net zero. This assessment also involved dynamic simulation modelling of a resident's energy demand and generation. Both these interventions have been critical to informing design decisions and have resulted in changes to the development process, the site layout and the roof designs, as well as the choice of materials and processes, and the introduction of active (energy-generating) technologies.

Barrier

With social housing, cost is key to ensuring homes are affordable for local authorities. But in trying to achieve the lowest cost, developers often rule out sustainable approaches as being too expensive. This project seeks to align the costs of this development with similar traditional builds, while also looking at the value of the entire life cycle of the building, and the long term impact of a home to people's pockets as well as the planet. It sets a blueprint for net zero social housing, and demonstrates the value to local authorities when scaled.

Whole life innovation

Central to the design process has been the data that is coming out of the dynamic simulation modelling. This has been innovative for pre-planning in the domestic new-build sector. Data from overheating assessments, alongside predicted energy demand, energy generation and residual energy balance have informed design decisions including roof design, solar shading, building fabric and energy systems. This approach is maximising the opportunity to achieve net zero carbon for this development. 

The data has informed decisions around the site layout, roof layout, and choice of materials that will improve the whole-life value of these new builds. The ABC’s suggestions included:

  • changing the roof designs to incorporate an in-roof PV system as the roof covering to optimise generation from solar PV
  • ensuring parking bays were next to homes to maximise EV charging
  • adding bicycle storage with power (for electric bike charging) and ensuring rear access for each home
  • adding solar shading to windows to reduce overheating risks
  • swapping construction materials to low-embodied alternatives
  • use of infrared heating panels and stratification hot water storage tanks

At this pre-planning stage of the development, the ABC has demonstrated through their modelling and analysis that investing in high performance building fabric, alongside renewable energy generation, storage and controls, can reduce energy demand sufficiently to negate the need for expensive heat pumps. Flintshire Borough Council has also committed to full certified Passivhaus standard to achieve these results, so they can proceed with the ABC’s suggestions. The outcomes are: warm, comfortable and affordable homes for residents; minimal reliance on the grid; and a blueprint for sustainable developments that other local authorities and developers can follow. This project is to be followed up with a further development comprising another 50 homes. The next stage is to leverage learnings from Greencore Construction which uses natural, low embodied carbon materials and modern methods of construction (MMC) to build its whole-life net zero carbon homes. ABC is working with Greencore Construction to validate this approach for leveraging additional investment into their products.

Collaborators

The Connah's Quay project was led by Flintshire Borough Council with guidance from the Active Building Centre (ABC). It had the support of the Welsh government. As principal designer for the project, Haliday Clark has fully engaged with the ABC, to build in the design suggestions and changes.

  • Active Building Centre
  • Flintshire Borough Council
  • Haliday Clark Architects

Lead support

Active Building Centre is funded by the Transforming Construction Challenge and Innovate UK. It provided the knowledge and expertise for this project.

Long Term Vision

The Connah's Quay development has allowed Flintshire Borough Council, Welsh Government and the Active Building Centre (ABC) to build net zero social housing, and create a blueprint that can be used by other councils and registered social landlords across Wales and the UK. By putting in place the suggested energy-saving measures from the ABC at the very start of the build, Flintshire Borough Council is demonstrating how to create new homes that are net zero carbon for operational energy, in a way that is scalable and can unlock value for councils and tenants alike.

Human Stories

By bringing in the Active Building Centre from concept stage, Flintshire Borough Council has maximised its opportunity to deliver homes that have minimal energy demand, maximum energy generation, storage, and control - giving residents every chance of living in healthy, warm and comfortable homes, and not living in fuel poverty.

Powerful Processes

The Active Building Centre's assessments and data at an early stage allowed decisions to be made about the processes and technologies incorporated into the design, such as incorporating an in-roof PV system to optimise generation from solar PV; ensuring parking bays were next to homes to maximise access to electric vehicle charging; adding bicycle storage with power (for electric bike charging) and ensuring rear access for each home; adding solar shading to windows to reduce overheating risks; swapping construction materials to low-embodied alternatives; and use of infrared heating panels and stratification hot water storage tanks.

Fascinating Facts

The annual energy costs of these homes could be negative, compared to £1,500 per year in traditional developments.  The predicted carbon emission savings (which will be offset from the grid) are just under 35 tonnes per year. This equates to around 1.8 tonnes per year per home, or one car driving 5,000 miles. Current estimates suggest that the new homes will show a massive 124% improvement on current regulations for energy demand and carbon emissions, and that potential energy cost savings for new residents could be as much as 100% more than minimum requirements. At a site level, the predicted generation is just under 150 MWh per year. This equates to an average of 7,555 kWh per year, per home. The annual energy demand is estimated to be just over 110 MWh per year, equating to an average of 5,503 kWh per year, per home. On an annual basis the development is expected to be energy positive.

Benefits

Active Energy
At a site level, the predicted generation is just under 150 MWh per year. This equates to an average of 7,555 kWh per year, per home. The annual energy demand is estimated to be just over 110 MWh per year, equating to an average of 5,503 kWh per year, per home. On an annual basis the development is expected to be energy positive. The high capacity for generation and energy storage will maximise the opportunity for these homes to be self-sufficient for as much of the year as possible, and allows for energy load shifting, which moves electricity consumption from one time period to another. As well as reducing bills, energy load shifting also supports wider decarbonisation by sourcing electricity from the grid at a time when carbon intensity is at its lowest. Current estimates suggest that the new homes will show a massive 124% improvement on current regulations for energy demand and carbon emissions and that potential energy cost savings for new residents could be as much as 100% more than minimum requirements.

Assurance
The certified Passivhaus Standard is proven to mitigate the performance gap, which exists primarily due to poor quality development from design stage, through to construction and handover.

Cost
The annual energy costs of these homes could be negative, compared to £1,500 per year in traditional developments. 

Emissions
At a site level, the predicted carbon emission savings (which will be offset from the grid) are just under 35 tonnes per year. This equates to around 1.8 tonnes per year per home - or the equivalent of one car driving 5,000 miles.