Gardenia - Letchworth Garden Quaters

Our design submission for RIBA’s international ideas competition Re-Imagining the Garden City. We were one of four practices selected to develop our ideas for the urban expansion of Letchworth Garden City.

The inspiration behind Gardenia is a connection with nature and Letchworth’s founding vision of a city of gardens.

Letchworth is growing and this new place is imagined as a branch, reaching into the countryside.

Like sap is the lifeblood of a branch, flowing back and forth, Gardenia’s branch is filled with people moving along it – going to work, going home, going to school or to the shops but ultimately engaging as a community; a living, vibrant, green movement spine.

And sprouting off this stem are the ‘leaves’ – quieter clusters of homes around garden spaces. Clusters are what Gardenia is all about; small communities of homes arranged around green spaces, not roads.

Micro clusters
Just 5 or 6 homes around a green / blue garden. Completely pedestrian spaces, with cars parked at the entrance.
Energy Centre
Provides heating for all homes and community buildings. Conveniently accessed from the main approach road for deliveries reducing traffic in residential areas.
Vertical Garden
A landmark visible from the city’s main Broadway but also a high level viewing point to look back onto the city.
City Farm and Kitchen
Sustainable Transport Interchange
The home of the sustainable travel club, housing hire bikes, tuk tuks, electric charging stations, car club bays, electric buggies and electric bus. Its solar roof contributes towards powering the various transport options.
Market Space
Garden Centre and Nursery
Retirement Village
Primary School
Wild Meadow Area
A haven for wildlife and perfect for residents that enjoy looking onto green spaces but don't necessarily want a garden to look after.
The Linear Garden
Made up of a patchwork of spaces - a boulevard, pocket parks, allotments, swales, bbq and picnic areas, wetland areas, rain gardens, sensory gardens, herb gardens, ponds, orchards, nutteries, wildflower meadows, arboretums, fitness trails and children’s play areas.
The Playing Fields
The 6 pitches on the playing fields have been slightly repositioned to introduce a new boulevard link to the community heart, reconnecting to the original garden city axis.
Natural Swimming Pond
This beautiful water feature is part of a sustainable drainage strategy and is 50% open water for swimming and 50% planted for wildlife.
Sustainable Travel Gate
Access across the existing shared surface path through to the southern access point will only be allowed for those cycling, walking, on electric bus or sharing from the Gardenia EV/AV fleet.
The Semi Autonomous Leaf Clusters
At the heart of these communities of houses are intimate, shared planted spaces like outdoor rooms. They will have greenhouses, planters, pergolas and seating areas.

Gardenia’s focal point is the community hub that sits on Letchworth’s primary axis, marked by the vertical garden – a landmark visible from the city.

Wrapping around this are activities that bring the community together – a school, community and business hub, city farm, retirement village, energy centre, transport interchange and garden centre. People of all ages live and learn alongside each other.

Gardenia aims to serve both body and mind, right from its heart all the way to the front door of every home. The linear garden is what connects each cluster of homes with the heart and the wider community, but it’s also a productive landscape that provides food, water attenuation, habitats and activity.


Gardenia's Community Hub

The Event Space
A thatched roof distinguishes this as a key communal building and links to the thached roof of the Garden City Institute building in town.
Energy Centre
A robust structure with a flue also on the Garden City axis.
Vertical Garden
A truly interactive sculpture that communicates Gardenia's vital statistics in realtime through light displays, covering energy generation, energy use and water consumption. Its internal core provides access to a viewing deck at the top
Solar Station
The roof of the transport hub will collect energy to contribute towards charging its fleet of electric vehicles.
Green Roofs
Many flat roofs throughout Gardenia are designed as planted roofs to further improve biodiversity and thermal efficiency.

Typical 'Urban Edge' Cluster

The shared gardens are filled with plants that are either good to eat or good for insects and birds.
Planting strips
These inset planted paving strips help reinforce that the road is part of the garden. Parking for houses to the north are between each home behind screens and for houses to the south at a secure, quiet parking area at the end of the cluster.
LED display
Digital display communicating the cluster’s energy generation and consumption, encouraging some healthy competition with neighbouring clusters!
Inside-Outside Living
A split level internal arrangement creates a higher ceiling height in the living space equals more sun and daylight and connection to outside.
These have been positioned within the shared garden, making growing a highly visible activity.
Productive Landscape
Residents are encouraged to utilise all communal and semi-private areas for growing their own food, with pergolas providing support for climbing plants and shading for the houses.
Solar Roofs
All roofs facing south are provided with integral PV panels to generate power for each home. Excess power generated can be provided to Gardenia's energy network
Asymmetric Roofs
Maximise sunlight and north facing gardens.
Raised Balcony Decks
These will give homes with north-facing gardens a sunny spot to sit, above their parking area.
The shared ‘outdoor house’
With its outdoor living, cooking and dining spaces, this is a place where everyone can get together.
Share station
Each cluster will have a car club electric vehicle and ebike. This free-standing solar pavilion will also be home to a secure, shared garden tool locker and a table out front will be a location for surplus fruit and vegetables, and a donation point for no-longer wanted toys and clothes and a communal book swap point. It is also the communal recycling and compost point.
Garden Room; to-grow
Homes need to be more flexible to meet today’s needs. Each Gardenia house will have a self-contained garden room that could be:
  • for an elderly parent, who wants independence but to be near family
  • for a grown-up child who is not yet able to afford a home of their own
  • an extra bedroom for a growing family
  • to support running a small business from home a b&b room or rented out to a longer-term lodger
  • to provide extra storage space – for cycles, gardening tools and everyday stuff that clutters up the home
Each cluster will produce its own honey.
A coop for keeping poultry will provide fresh eggs for residents.
Water Tank
Each cluster will collect its own rainwater for the upkeep of the central gardens. It is sized to store winter rainwater for summer use. Being above ground will be a good visual reminder of water as a precious shared commodity. A gauge will show how full it is.
Fruit cages
Protected area for growing raspberries, red currants, black currants and gooseberries.
Fruit Trees
Each cluster will have apple, pear and cherry trees.
Small holes in the bottom of fences allow hedgehogs to move between gardens

Typical 'Rural Edge' Cluster

Permeable Paving
The road around the central green area has inset diamonds of planting, making the whole space feel like a garden and helps rainwater soak into the ground.
Urban Farm-Houses
These semi-detached houses have a barn-like character and have growing spaces integrated into their roofs.
Garden Rooms
Flexible opportunities for homes to grow according to need (expanding or aging family requirements).
Porches with Perches
A place to enjoy a cup of tea and have a chat with your neighbours.
'Habitat' Houses
The facade is made of integrated bird and bat boxes.
Cluster Gateway
Feature trees to mark the entrance into each cluster
Share Area
A place where residents can come together and grow.
'Leaf' Houses
Roofs designed to photosynthesise light into energy and collect rainwater in a central 'stem' gutter down into a large underground tank. This will be used to store winter rainwater for use in the summer.
Integrated Sunspaces
These sunny bright spaces connect residents with their gardens and create opportunities for indoor growing.

The Productive Landscape

Nature Decks
Houses facing onto the nature reserve have raised private decks out over the landscape to protect habitats
Bushes, shrubs, flowers and trees create a haven for wildlife.
Formal planting of fruit trees adds interest and enjoyment for all, from admiring the blossoms in spring to eating the fruit in autumn.
Parkside Homes
These homes enjoy views onto the green spine and are a mix of larger apartments and built-to-rent homes, and semi-detached houses.
The landscape provides opportunities for formal and informal activities, including play areas, tennis courts, a trim trail, communal BBQs, paths and cycleways.
Sculptural forms in the groundwork allows people to sit and enjoy the landscape (and hopefully some sunshine).
Large trees line the green spine to clearly delineate it from the roads.

Keeping up with the Gardenians

Three generations of one family tell us about life in Gardenia.

Community news

Nature Inspired

Gardenia’s Linear Garden Concept

Gardenia looks to create a rich environment for people and nature to thrive in and enjoy

Organic Cell Structure of Gardenia

Gardenia creates lots of neighbourly clusters focussed on people and community spirit which forms the basis of a flexible phasing strategy

Places with Distinctive Character

Gardenia is divided into areas of different characteristics that reinforce its identity

View the full submission boards.

The team

The core team brings together expertise in Architecture, Landscape Design and Urban Design. They’re also part of our Place studio – a home for initiatives aimed at influencing how we go about Shaping Future Places.

The introduction of our future residents – Ray, Anna and Howard – has helped us visualise more holistically the possible impact of our proposals on the communities who could be expected to live in and around our model settlement.

A key design idea is to substitute streets for clusters. Placing small green spaces at the heart of each cluster encourages community and implies a sense of ownership. It’s what garden cities are all about.

At the heart of the masterplan is a garden. Not large in footprint but stretching skywards, the vertical botanic garden will re-establish the city’s original strong axial geometry set out by Parker and Unwin. This striking planted structure will become the emblem for the development.

Shaping Future Places

We believe that together, things can be done better; we should create places which will thrive long into the future.


A collection of interviews with the people that use our projects every day. These are the true judges of the spaces and places we create.