Catherines Walk is a £5.7 million affordable housing development in Barnsley, consisting of 40 houses, 8 apartments, and 6 bungalows. The project presented a significant technical challenge: the requirement to install a high-density, adoptable drainage network within an exceptionally tight and awkward site footprint.
The Brief
With a 15-month build programme, the project required a seamless transition from the 110mm internal soil and waste systems to a robust, adoptable sewer network. The original specification called for an alternative system, but the client and groundworker needed a solution that offered better hydraulic efficiency, faster installation times, and full compliance with Building Regulations Part H and Water Authority Standards (Section 104).
Our Solution
Working proactively with the Contractor (Watson Groundworks) and the Consultant Engineer (WSP), Polypipe Building Products provided a system-led solution that addressed both On-Plot (private) and Off-Plot (adoptable) requirements, ensuring the full range of underground drainage was utilised effectively.
1. Off-Plot Infrastructure: For the main adoptable sewer run, Polysewer was selected for its high ring stiffness (SN8), making it suitable for installation under the estate roads and highways. To replace labour-intensive concrete manholes, we supplied 600mm Adoptable Inspection Chambers. These modular units met all Design and Construction Guidance requirements while being significantly safer and faster to install in a congested footprint.
2. On-Plot Efficiency: Within the property boundaries, a comprehensive 110mm PVC-U network was utilised for the foul and surface water runs. A key advantage was our single piece moulded underground fittings; the factory-fitted seals in our fittings ensured that joints remained 100% water-tight even during the rapid backfilling required to keep the project on schedule.
3. System Connectivity: The flexibility of the Polypipe Building Products system allowed the site team to navigate the awkward footprint and achieve a clean transition from the private house drains into the main sewer network. By using Polypipe’s integrated range of bends and inspection chambers, the contractor was able to maintain the necessary gradients and flow rates across the entire site, from the first fix at the building to the final sewer connection.
The Result
By switching the specification to a unified Polypipe Building Products system, the project achieved a more efficient footprint and a noticeable reduction in lead times. The lightweight nature of the PVC-U and Polysewer ranges meant that Watson Groundworks could move and install components without the need for heavy lifting machinery, improving on-site safety and speed.
The project was completed in Autumn 2019, providing 54 much-needed homes for the Barnsley community with a future-proofed drainage infrastructure that was delivered more cost-effectively and with greater hydraulic reliability than legacy materials.
Genuit Group Synergy: From Roofline to Retention
While the Catherines Walk project highlights the efficiency of Polypipe Building Products' residential drainage, the development’s overall water management strategy was a masterclass in Genuit Group synergy.
To manage the significant surface water requirements of a 54-home development on a high-density footprint, the project integrated high-capacity attenuation solutions from our sister division, Polypipe Civils & Green Urbanisation.
The Civils Component: A large-scale attenuation tank was required to manage storm water run-off. This was achieved using 20 x 6m lengths of 1800mm RXL pipe, providing a massive 320m³ of storage volume.
The Integrated Path: This large-scale infrastructure (Off-Plot) was connected seamlessly to our residential (On-Plot) surface water gullies and 110mm PVC-U collector lines.
The Result of Synergy: By utilising the combined expertise of the Genuit Group, the project team benefited from a single point of contact for the entire water journey.