Hurlstone Associates was invited to assess persistent low-pressure issues across three residential blocks on a housing estate in East London and Kennington, managed by a local housing association. Residents had been experiencing inadequate pressure for some time, creating operational challenges and making long-term infrastructure planning difficult.
Initial proposals explored large, centralised booster sets with break tanks fed from the Thames Water mains supply. While viable in principle, these solutions required significant plant space that simply was not available on site.
A tank manufacturer provided various break tank options; however, all required dedicated housing areas that the estate could not accommodate. Packaged tank-and-booster systems in weatherproof enclosures were also considered. These units can be supplied up to 20,000 litres as standard and would occupy one to two car parking spaces. In addition to long lead times, these systems would have required extensive pipework surveys and major enabling works, making them impractical in the short term.
Site Constraints
The only feasible installation locations were either the riser cupboards within each block or the adjacent bin stores. The bin stores offered a potential footprint but had restricted headroom, ruling out previously used larger booster solutions. Access to some riser cupboards was also extremely limited, in certain cases just 500mm wide, creating logistical challenges for delivery and installation.
The Engineered Solution
To address these constraints, we specified the Arrow Valves BTAF5-8 Pent-A-Boost from Arrow Valves.
This compact unit delivers up to 2 l/s with the selected BTAF5-8 configuration generating 3 bar at 2 l/s, ideal for stabilising pressure across the affected dwellings. The unit requires a minimum dynamic inlet pressure of 1 bar, which was confirmed by Thames Water.
The Pent-A-Boost units fit comfortably within the bin store locations, requiring routing of a DN32 supply from the riser cupboard. Where riser installation is preferred, the units can be delivered in three separate components to accommodate tight access restrictions and reassembled on site by the installing contractor.
Given the proximity to electrical services, we also recommended the addition of a drip tray with integrated float switch protection. If water collects within the tray, the float switch activates, isolating the water supply and stopping the pump, providing an added layer of protection. The drip tray footprint is 710mm², making it suitable even within the restricted spaces available.
Another useful unique feature of the Pent-A-Boost is that it has a built in automatic WRAS approved mains bypass, so if there is a power failure or an issue with the Pent-A-Boost then the building will get an uninterrupted supply of water albeit at mains pressure until either the power is restored or issue resolved.
Outcome
While not the original long-term masterplan solution, this approach provides:
- Rapid deployment with minimal disruption
- No requirement for new plant rooms or external enclosures
- Reduced capital outlay
- A practical trial solution that can be implemented quickly
- Full compliance with UK Water Regulations
This project demonstrates how space constraints and limited infrastructure do not necessarily require major civil works, with the right compact booster solution, pressure performance can be restored efficiently and effectively.
Full technical details can be viewed here:
https://www.arrowvalves.co.uk/wp-content/uploads/2025/10/btafsingledatasheet.pdf
Covering Email (Campaign)Case Study: Compact Booster Solution for Low-Pressure Housing Estate
Dea Colleague
We recently supported a local housing association across three residential blocks in East London and Kennington where residents were experiencing ongoing low-pressure issues.
Large, centralised break tank and booster options were considered, but space constraints, long lead times and significant enabling works made these impractical. Instead, we developed a compact, site-sensitive solution using the Arrow Valves BTAF5-8 Pent-A-Boost unit.
The selected configuration delivers 3 bar at 2 l/s, operates from a confirmed 1 bar dynamic inlet pressure from Thames Water, and is compact enough to fit within bin stores or riser cupboards, even where access is restricted to 500mm. Units can be delivered in three pieces for ease of installation, with optional drip tray protection for installations near electrics.
This approach allowed for a fast, low-disruption trial solution without the need for new plant areas or external tank enclosures.
And the datasheet for the BTAF Pent-A-Boost: https://www.arrowvalves.co.uk/wp-content/uploads/2025/10/btafsingledatasheet.pdf
If you’re dealing with similar pressure constraints and limited plant space, we’d be happy to explore options with you.
Best regards,
Hurlstone Associates