Kingcombe Stonbury were contracted to design and build a sustainable, ornamental ‘Amenity Pool’ in an Inner-City Development comprising of 500 residential units, within a series of multi-story blocks and retail space.

The location is adjacent to the A13, one of the main arterial routes out of London, causing environmental considerations to be a key priority. The pool was located on a podium level above retail and plant areas.

The design and construction were particularly challenging as the build required naturally filtered water in a play area pond as well as the ability to attenuate rainwater from the surrounding rooftops, all at podium level. This meant sustainable urban drainage was a planning requirement of the scheme and as such, formed a key part of the design. The roof water from the towers is collected and attenuated by the pond prior to being discharged into the public sewer, this mitigates the high risk of flooding during and after a heavy storm.

The pools rooftop location called for a robust waterproofing solution with a warranty. We therefore selected Firestone EPDM to use as the waterproof membrane. This material was chosen because of its long life and the technical involvement by the manufacturer who detail every joint, junction and termination in the project. They also carry out QA inspections to ensure compliance with their requirements and offer a Warranty for the project.

Because the pond does not form part of the roof waterproofing system the pond liner had to be compatible with the waterproofing and was laid as a second layer to form the waterproof containment.

The demanding logistics of the congested site called for close cooperation with the main contractor especially in the early lifting of materials with the tower crane, initially sited in the middle of the pool location. When the tower crane was dismantled the void in the floor was filled to allow work on the pool to commence. Access to the working area was challenging, being flanked on three sides by the accommodation towers and on the fourth side by the A13.

Biological filters were installed alongside aquatic emergent plants to quickly establish the necessary ecosystem that would suppress algae growth, the water is recirculated through the filters and aerated with a small fountain display. The sinuous rill is also fed with water from the pond to form a running water feature within the garden. The pool also features an automatic water make up to maintain water levels due to evaporation loss during long periods of dry weather.

The scheme was completed satisfying the SuDs requirement for attenuating roof water drainage and was handed back to the client after inspection.