Sustainable windows enable energy savings on Isle of Dogs

A plan for safe homes
One Housing owns and manage over 17,000 homes in London and the South East, providing homes to around 35,000 customers. Kelson House, which is located on the Isle of Dogs, is a 25-storey purpose-built block, featuring 145 two-bedroom duplex flats, and housing more than 580 residents. Originally built in the 1960s, some of the block’s fixtures and fittings, including the windows, were in need of upgrading Its location on the edge of the River Thames also means it is regularly exposed to high winds, so external features such as its 20-year old windows needed to be upgraded with more resilient and weatherproof materials. 

As well as finding a window solution which would substantially out-perform its predecessor, One Housing was mindful of its own impact on the environment. It therefore wanted to ensure the 1,000 windows coming out of the building were not sent to landfill, and could instead be responsibly recycled back through the manufacturing process. 

Six collaborative teams
In order to make the project a reality, six key stakeholders came together to design and plan a window replacement project, while minimising disruption to residents. As the owner of the building, One Housing Management appointed building surveyor Steven De Jesus to oversee the project and work with: principal contractor specialising in facades, Lawtech Group; specifier and surveyor, GDS; commercial installers, Symphony Windows; window manufacturer; and window profile manufacturer, REHAU. 

In order to establish what the final window design would look like, REHAU initially worked with GDS’ Project Manager to organise technical drawings and the specification process. Most importantly, they needed to find a solution that would improve the lives of residents through increased thermal efficiency, safety and ease of maintenance. 

Total solution
Despite having a plethora of variables and window styles to consider, the companies made a unanimous decision to select REHAU’s TOTAL70 tilt and turn windows following a presentation by Kevin O’Neill, Commercial Manager for REHAU Windows Division. 

Improving thermal performance of the apartments was paramount to the project. Alongside having to meet Building Regulations, the TOTAL70 solution was able to increase the Thermal Efficiency (U-Value) of the windows by around 30% from the original, passing on significant energy savings to the residents. 

Also, with fire prevention being the number one priority for all major housing associations and high-rise developers, REHAU was asked to include any additional fire safety features to common areas. Upgrading the windows to include Automatic Opening Vents (AOV) meant that should there be a fire in the corridors or on the stairwell, the fire alarm system would activate the windows to open automatically.

Additional safety measures were introduced into the design which included window restrictors, adding critical safety benefits particularly prevalent for households with children present.

To improve air quality for residence, prevent condensation, and subsequent costly repair and maintenance bills, trickle vents were also incorporated into the windows allowing for effective ventilation.

Additionally, the teams also had to consider weather and wind-loading classification to ensure the windows performed properly and were structurally secure and robust.

A staged installation
In order to minimise disruption to residents during the replacement programme, Lawtech Group and Symphony Windows developed a mast climber scaffold system that enabled them to replace one property at a time. This also offered a safe solution with regards to working at height. 

In addition, Symphony Windows was also responsible for ensuring the old window frames and glass were processed through the necessary recycling method to improve One Housing’s environmental responsibility.

Although the process is quite complex, fundamentally the PVC, steel, rubber, metals and glass is stripped, sorted and reused in various forms. For example, the PVC is treated and enhanced to be reengineered and extruded as part of the central core of a new window or door, with virgin PVCu material used on the exposed faces of the new window / door profiles.

“So far the project has gone really well and we’ve already received letters of thanks from residents who have seen reductions on their energy bills. In my job, it doesn’t get better than that,”

Comments Rasheda Yasmin, Resident Liaison Officer at Kelson House.

Kevin O’Neill, Commercial Manager for REHAU Windows Division, concludes:

“This has been an incredible project to be involved in. We’re particularly proud to be part of such a sustainably-led partnership. Recycling is something REHAU is equally passionate about having recently invested in our own multimillion pound recycling plant that allows previously installed windows and doors to have their materials utilised.

Every single company we have worked alongside is at the top of their game and have been able to deliver an astounding result for One Housing. We’re proud our windows were installed here.”