Phil Allen is the Founder of PAD landscapes
TIDE Bankside sky gardens at 135 Park Street, London. Landscape design by PAD Landscapes.
Landscape is no longer the finishing touch
For years, landscape has often been treated as the final layer of a project: the softening, the garnish, the
"nice-to-have" that arrives once the hard decisions have already been made.
That approach is becoming increasingly difficult to justify.
The construction industry is already dealing with the consequences of climate change. Overheating,
flash flooding, Biodiversity Net Gain (BNG), air quality targets, retrofit, carbon scrutiny and changing
occupier expectations are no longer future challenges, they're today's reality.
Green infrastructure sits across every one of them. Done properly, it helps developments manage water,
reduce urban heat, improve biodiversity, support occupier wellbeing and improve long-term resilience.
That means designing, engineering, costing, constructing and maintaining it as part of the development
strategy from day one, not adding it at the end. For developers and contractors alike, that's an important
shift in thinking. Landscape is no longer simply about appearance; it's become part of how a building
performs.
Good landscape starts with good coordination
One of the most common mistakes is bringing landscape into a project once the structure, drainage
strategy and servicing have already been fixed.
By then, many of the decisions that determine whether green infrastructure succeeds have already been
made.
If structural loading hasn't allowed for meaningful soil volumes, drainage has already been designed or
maintenance access hasn't been considered, delivering successful planting becomes much harder, and
considerably more expensive.
The answer is to bring landscape architects into projects much earlier.
Landscape can't be considered separately from architecture, structural engineering or building services.
Waterproofing, drainage, irrigation, fire strategy, wind exposure, soil depth and maintenance all need to
work together.
Get that coordination right from the outset and green infrastructure becomes an asset that strengthens a
development. Leave it until the end, and it quickly risks becoming just another planning condition to
satisfy.
Ryder Court bespoke roof gardens in St James’s, London. Landscape design by PAD Landscapes.
Every roof should be asked to work harder
London has thousands of flat roofs that remain underused despite offering enormous potential to
improve biodiversity, reduce overheating, attenuate rainwater and create valuable outdoor amenity.
Cities such as Basel have shown what is possible by treating green roofs as part of urban infrastructure
rather than optional enhancements.
Basel leading the way
Roof gardens can deliver cooling, biodiversity, water attenuation and commercial value, but only when
structural loading, drainage, wind exposure, irrigation, soil systems and long-term maintenance have all
been considered from the outset.
PAD landscapes’ roof garden at Ryder Court in St James's is a good example of this joined-up thinking.
Planting, drainage, bespoke soil systems and maintenance requirements were coordinated from day
one, creating a roof garden designed to perform for the long term rather than simply look good on
completion.
Ryder Court case study
The same principle applies at Queen Victoria Street, where a previously inaccessible roof has been
transformed into an outdoor workplace with mature tree planting and generous amenity space.
95 QVS
The lesson isn't simply that every roof should be green.
It's that every roof should be asked to work harder.
As more developers prioritise retrofit over demolition, roofs are becoming valuable assets that can help
extend the commercial life of existing buildings while improving occupier experience. Perhaps the
greenest development isn't demolition followed by reinvention, but intelligent reuse supported by high-
performing landscape.
Designing for heavier rainfall
London's drainage network was never designed for the intensity of many of the rainfall events we're now
seeing.
Every development that sends water straight into already overloaded pipes adds to a city-wide problem.
This is where sustainable drainage systems (SuDS), rain gardens, permeable paving, blue-green roofs
and thoughtfully designed public realm become far more than planning requirements.
The most effective landscapes are no longer passive spaces. They are working surfaces.
Copenhagen responded to major flooding by redesigning streets and parks to slow, store and direct
stormwater rather than relying solely on larger drainage infrastructure. London will also need this kind of
joined-up thinking.
Copenhagen - how to flood-proof
TIDE Bankside demonstrates how this can work in practice. Water management, biodiversity and
placemaking were considered together from the outset, with rainwater captured and reused across the
site rather than simply discharged into the drainage network.
Tide case study
The lesson is straightforward: drainage, landscape and engineering should never be separate
conversations.
Queen Victoria Street roof gardens at 95 Queen Victoria Street, London. Landscape design by PAD Landscapes.
Biodiversity is more than meeting a metric
The introduction of Biodiversity Net Gain has undoubtedly changed conversations around ecology, but
meeting a metric isn't the same as restoring nature.
UK Gov BNG intro
A spreadsheet can demonstrate compliance.
It cannot create habitat.
Creating habitat depends on good design, appropriate planting, healthy soils and long-term
management.
New Marlborough Yard in Waterloo, PAD’s public realm demonstrates this approach. Climate-adapted
trees, ecological habitats, improved public realm and wildflower roofs were designed as one connected
landscape rather than a series of isolated green interventions.
Public realm - climate-resilience
When ground-level space is limited, roofs, terraces, podiums and façades all have a role to play.
Climate-conscious landscape design isn't about squeezing greenery into leftover spaces. It's about
making every available surface contribute towards cooling, biodiversity, water management and better
places for people.
What construction teams should be thinking about
One question that comes up repeatedly is whether green infrastructure adds cost.
The honest answer is yes, if it's introduced too late.
Retrofitting ambitious landscape proposals into a fixed structure, drainage strategy and maintenance
budget is where costs escalate and compromises begin.
Bring landscape into the project early, however, and it starts reducing risk rather than creating it.
For contractors and developers, the practical lessons are straightforward:
- Bring landscape architects into projects as early as possible, alongside architects and engineers.
- Coordinate drainage, structural loading and soil volumes from the outset.
- Design maintenance and irrigation into the project rather than treating them as post-completion issues.
- Treat soil as a construction material, trees as long-term assets and irrigation as infrastructure.
Successful green infrastructure depends just as much on build quality as good architecture or
engineering. Planting on exposed rooftops requires technical knowledge, while public realm detailing
must withstand servicing, heavy footfall and increasingly extreme weather.
The landscape has a habit of revealing construction quality remarkably quickly.
Building developments that will still perform in 30 years
Future-proofing London isn't about making every building look greener.
It's about creating developments that continue to perform as the climate changes.
It means reducing overheating through tree planting, managing water through sustainable drainage,
supporting biodiversity and recognising that landscape architecture has become fundamental to how
buildings function—not simply how they look.
London will continue to grow.
The question is whether that growth produces places that are harder, hotter and less resilient, or
developments that are better equipped to deal with the environmental challenges ahead.
Landscape architecture won't solve climate change on its own. But if the industry continues to treat it as
the garnish rather than the infrastructure, we'll keep designing developments for yesterday's climate
instead of tomorrows.
About:
Phil Allen is the founder of PAD Landscapes, a landscape architecture studio established in 2017. PAD
landscapes work across the public realm, commercial, residential, and mixed-use developments,
creating urban landscapes that emulate natural systems and help cities respond to climate change,
biodiversity loss, and changing patterns of use.
