Header: Sloane Street Transformation / Photo credit: Hufton + Crow
Landscape architecture is becoming one way cities work better as it helps cool streets, manage water, support biodiversity, improve walkability and make public space more useful. In two BLT Built Design Awards winners, that wider role is easy to see: on Phi Phi, a wastewater facility becomes an ecological park, while in London, one of the city’s best-known streets becomes greener, more comfortable and easier to move through.
The Phi Phi Wastewater Management Ecological Park | Arsomsilp Community and Environmental Architect | Phi Phi Islands, Thailand
Koh Phi Phi, once an ecological paradise, now faces environmental degradation from tourism-driven wastewater pollution. When the Wastewater Management Authority expanded treatment capacity with underground tanks, the land above could have become the usual leftover lawn. Arsomsilp Community and Environmental Architect instead turned the 7,072-square-metre site into a park that treats water, supports biodiversity and gives the community somewhere to be.
Treated water flows into a phytoremediation pond for final polishing before discharge, while the same pond also works as a stormwater basin and irrigation reservoir. Native planting reduces maintenance, while walking trails, a sports court, bouldering walls and an outdoor gym make the infrastructure part of everyday life. Interactive signage, access to the treatment process and the bottle-cap-clad Swimming Fish Tower turn the site into a living classroom rather than something to hide behind a fence.
View The Phi Phi Wastewater Management Ecological Park
Sloane Street Transformation – Luxury Green Boulevard | Cadogan | London, United Kingdom
On Sloane Street, the infrastructure is less obvious but just as measurable. The one-kilometre transformation, led by Cadogan in partnership with the Royal Borough of Kensington and Chelsea, with John McAslan + Partners, Andy Sturgeon Design and WSP, widened pavements by 23% and introduced over 100 new trees.
The project delivered a 175% increase in biodiversity and a 17% increase in Urban Greening Factor through over 100 new trees and diverse perennial planting, helping mitigate urban heat island effects and support year-round ecological health. The project supports microclimate regulation and air purification while softening the urban environment.
Visitors now enjoy a serene landscape, once a traffic-heavy route to a destination for relaxation and retail; reaffirming the Street’s prestige and merging heritage with ecological innovation for future resilience.
View Sloane Street Transformation – Luxury Green Boulevard
Landscape architecture as essential urban infrastructure
These projects look completely different, but they both prove that landscape architecture is most interesting when it is asked to solve something. One turns water treatment into public space; the other uses planting and pedestrian space to improve how a street performs. That is exactly the kind of work the BLT Built Design Awards is designed to recognise: projects with a clear idea, a strong response to context and something useful to say about where the built environment is heading. Winning brings independent recognition, year-round visibility on the BLT Built Design Awards platform and access to PR and promotional opportunities.
The 2026 BLT Built Design Awards are open for entries across Architectural Design, Interior Design, Landscape Architecture and Construction Product Design. If your project proves that landscape can do more than look good, submit your project before October 4.
