Rainscreen – Leading Regeneration
“To someone coming out of the slums… the idea of going into a house with a bathroom, a proper kitchen, hot water… it was their dream, and it didn’t matter a damn to them if it was in a multi- storey block or a cottage… they wanted as many dwellings as quickly as possible!”
“As we were leaving, at the exit, Harry Watton suddenly said, ‘Right! We’ll take five blocks’… just as if he was buying bags of sweets!”
G. Sheppard Fidler – Birmingham City Architect 1954-62
The social housing construction programmes of the post-war era remain some of the most ambitious, both in terms of scale and size, in British history. Tasked with bringing millions out of squalid conditions, the estate builders embraced cutting-edge designs, approaches and technologies to achieve their goals and, in their early years at least, many of the developments delivered on their vision of a brighter future.
Sadly, the early promise was not to last. With volume prioritised above all else, many of the estates were poorly thought-out, badly designed and completed to a low standard. Furthermore, with many of the blocks pre-dating the first regulatory requirements for minimum U-values, the flats were often cold and expensive to heat. As a result, the estates quickly fell into disrepair and within two decades of their completion were already being described as ‘sink’ estates.
In the previous blog we looked at how some of these blocks are being revitalised through large-scale retrofit programmes, however, in some cases the inherent flaws in the planning, design and construction of the estates make it preferable to start afresh. High quality rainscreen cladding systems can provide a number of benefits for these new developments including significant design freedom for architects, fast-track installations, long-term durability and excellent energy performance when paired with premium performance insulation. The Woodberry Down estate in North East London showcases the benefits of this approach.
An ‘Estate of the Future’
Planned by John Forshaw in 1943, the original Woodberry Down estate was one of the first to include eight storey blocks within a suburban area. The blocks were laid out either side of the newly created Woodberry Down road in a Zeilenbau (row-house) plan. Many of the original tenants provided glowing references:
The excitement of opening the front door, our own, and finding a nice living room, large bedroom with fitted wardrobe and fitted chest of drawers… separate toilet, a lovely kitchenette full of cupboards and shining stainless steel sink and draining board. What more could we want?
Over time, however, the buildings aged poorly.
Unlike later estates, this premature ageing owed less to corners being cut and more to material shortages. For example, the steel reinforcement for the floor slabs on many of the blocks was cut from Anderson air shelters and the lack of both steel and bricks also led to the monolithic design of many of the blocks with reinforced concrete faced in render.
For years, tenants suffered from damp and poor insulation, whilst the estate’s grim aesthetic infamously saw it used as a set for the Warsaw Ghetto in the 1993 film Schindler’s List. In 2002 a structural evaluation concluded that 31 out of 57 blocks on the estate were “beyond economic repair”. Hackney Council agreed a deal with Berkeley Homes to demolish and rebuild the estate, replacing the social rented properties and providing over 3,500 additional private units.
A new chapter
The eight stage regeneration plan for the Woodberry Down estate will roll out over 20 years. Once completed it will include three new public parks; a community centre and library; a children’s centre; and retail and commercial spaces. Rainscreen cladding systems were installed across the development with anodized aluminium facades. On Kick Start Site 2, for example, a rainscreen system was used to crown the upper storeys of the social housing blocks. The aluminium cladding acts independently of the rest of the brick façade and provides a stylish highlight for the eight storey blocks.
To help protect future tenants against issues such as fuel poverty which had affected the original estate, BREEAM ‘Very Good’ certification was targeted at an early stage in the planning process. To achieve the excellent fabric performance needed to attain the certification, whilst also maximising living space for the tenants, Kingspan Kooltherm K15 Rainscreen Board was specified for the rainscreen sections.
The product helped to meet the target fabric performance but with a minimal external construction thickness. Its 2008 BRE Green Guide Summary Rating of A+, and its ‘Excellent’ certification to responsible sourcing standard BES 6001, enabled it to contribute towards the award of further credits within the BREEAM assessment.
As the rainscreen sections extend beyond 18 metres, excellent fire performance was another central concern for the project. Kingspan Kooltherm K15 Rainscreen Board offered what was needed.
A better future
In 2014 an independent survey of the new estate’s residents revealed that overall life satisfaction had been transformed, with 90% of residents feeling satisfied with their living conditions, compared with the UK baseline of 60%. The breath of new life for the estate is a clear example of the benefits that rebuilding can bring to certain estates and the advantages rainscreens can offer, both over the short and long-term.
Catch up with previous blogs in this series:
Share this blog post with your friends and colleagues by clicking on the social media icons below.