Government v Builders Drainage Row

There has been a lot of chat in the news over the past few days relating to the ongoing row between the government and house builders regarding drainage on new developments. For more on this story please see below.

“A four-year delay to rules meant to prevent new housing developments making floods worse could finally be ended. The policy has been paralysed, with builders rejecting demands that they should install ponds and grassy hollows to catch water running off roofs.

There is still deadlock on this but it is understood that a deal has been reached over who pays to maintain any new anti-flood landscape features.

Councils will be able to bill owners of new homes for maintenance. The councils argue this is fair as owners of existing homes have to pay to have their run-off water treated by water firms through the sewerage system.

The Flood Act of 2010 obliges builders to landscape developments so water from roofs and driveways seeps into open ground, rather than rushing into the water system.”

For more on the story please click here –

Whilst some of the solutions offered involve building surface drainage systems using open ground and ponds, this will not provide a viable solution in densely packed urban Wallbarn M-Trayareas. It is therefore essential that we find solutions for existing buildings and infrastructure and the Wallbarn M-tray is proven to help both drainage and the issues of flooding.

Finding a Viable Solution

Our m-Tray green roofs can “attenuate” (absorb) up to 50% of rainwater on flat roofs, and also slow down the initial deluge. By taking pout 50% of the rainfall and then slowing down both the start of drainage water leaving the roof/podium deck and entering the drainage pipes, and making that flow slower and over a longer time period. This puts a lot less pressure on the (often Victorian) drainage system.

Offering Immediate Benefits

M-Tray green roofs can be retrofitted on existing roofs and concrete areas so can bring a benefit immediately to areas without having to build huge masterplan residential and drainage areas. M-Tray green roofs do not bring an instant solution to ALL flooding, but it can mitigate in small ways on multiple domestic dwellings as well as being part of larger schemes. It can be incorporated into the masterplan at the earliest stage or it can be retro-fitted.

This is a massive advantage. We have to work with what we have got and as we are not going to be tearing down huge areas of Victorian construction to create “new towns” and “new ways of living” – remember the 1960s tower blocks and the 1970s Birmingham Bull Ring development for the huge errors in many of such schemes? We need to adapt and improve on what infrastructure we have. M-Tray is doing this in incremental steps, rooftop by rooftop.

Cost-Effective Solutions

The price for green roofs has come down tremendously in recent years, making green roofs possible and realistic now. Even in 2006, they were marketed at circa £120 per m2, now M-Tray, an easy-to-fit instant green roof which is fully contained within a cassette tray module (so no messy soil and plants fall out during transport and installation) is available from £44 per m2.

For more information regarding Wallbarn’s Green Roofing products and our M-Tray green roofs please call Tel. No. 0208 916 2222.