In the same way that a parasite is fed and sheltered by its host, so-called 'parasitic architecture' feeds off a pre-existing structure, providing alternative solutions to overcrowded spaces. In an age of mass migration, impossible rents and a general lack of space, could parasitic architecture be the key to our growing housing needs and lack of space in major cities? Let's take a look at some examples.

Built in 2001, the Las Palmas parasite house has gone on to become one of the parasite movement’s most iconic structures. The bright green object, which sits on top of the former Las Palmas warehouse, presents a design solution for small-scale parasitic living without sacrificing bespoke design.

Don’t be fooled by its compact exterior, because there’s plenty of space for comfortable living inside. The walls of the Las Palmas house were constructed of laminated timber panels, which builds on the notion of affordable prefab building solutions.

While the prefabricated structure was delivered and constructed in a number of days, design elements, such as its floor-to-ceiling windows and terrace, prove that affordable housing can go hand in hand with modern design.

A densely-packed city with one of the strictest building regulations in the world, Paris is facing a housing crisis that is beyond compare. While most cities are replacing old buildings with sky-high apartment blocks, French architect Stephane Malka is challenging the system through his adaptable parasitic creations, while allowing Paris to retain its romantic skyline.

Perched on top of traditional Parisian buildings, Malka’s prefab rooftop apartments address many of the housing issues felt by Parisians today. The structures are aesthetically pleasing, spacious, quick to build and affordable.

Each of Malka’s creations offer a spacious, modern interior and a terrace with the best views of the city. Though they aren’t to everyone’s liking, the younger generation who often struggle to pay extortionate rents would agree that Malka’s creations beat living in cheap maid’s room conversions, which are often as small as 86 square feet.

Though he continues to design public housing, Malka has gone on to address the issue of homelessness in France through his A-Kamp47 project. These parasitic structures consist of a series of structural tents, which can be attached to disused surfaces, such as railway bridges and arches.

Where cardboard shelters and conventional tents are exposed to damage, theft and police raids, Malka’s suspended structures provide a safe and warm environment for the homeless, while creating a thinking space for a united community with a voice.

James Furzen’s award-winning parasitic pods are revolutionising the way we house the homeless in overpopulated cities like London. Each pod is designed to be attached to a host building while fulfilling their functions of providing a safe and sheltered environment for rough sleepers.

Each pod was designed with compact features in mind, including a single bed and foldout shelving units. Large windows allow light into the pods, while creating an airy atmosphere in a compact space. The structures can be installed independently or as a community.

Architecture firm Adamo-Faiden gave new meaning to a vacant rooftop of a 15-storey apartment block in Buenos Aires by transforming it into a glass structure that looks more like a greenhouse than a home.

Camouflaged by a sea of green, the Piñeiro House enhances indoor-outdoor living with the addition of plant boxes to its exterior walls. The plants create a calming environment, shading its inhabitants from the heat of the sun while enhancing privacy.

The 215 square feet apartment consists of a living area, bathroom and kitchen, as well a 108 square feet terrace. The project encourages the utilisation of thousands of disused rooftops, which dominate the Buenos Aires skyline.

Another parasitic housing project that addresses the issue of space restrictions and lack of affordability is All(Zone)’s Lighthouse Project, which proposes small-scale nomadic living in tropical climates.

The 124 square feet homes provide temporary housing solutions through simple structures that are quick to assemble without the need of foundations. In cities such as Beijing, where space is limited, unconventional locations, such as car parks and derelict buildings, can offer housing solutions for the homeless.

Each structure offers ample space for a bed, while built-in shelving units provide a temporary storage space for the inhabitant’s belongings. Perforated walls allow light and air to enter the structure, while creating a private environment.

A slim house has been slotted between two pre-existing properties in London in a space that had been left vacant for decades. With a street frontage of less than three metres, it’s no wonder the site had been left in this state for so long.

Boyarsky Murphy Architects were faced with the challenge of fitting a home into a site measuring 118 by 80 square feet. Making the most of the limited space they had to work with, the architects created a series of boxlike forms, which were wedged into the vacant space in alternating angles.

Inside, the property is a far cry from its slim exterior. Set over three floors, its designers have made the most of natural light sources by inserting wall-to-wall windows, which dominate the front facade of the structure. Frosted glass has been used to allow light in while retaining privacy for its inhabitants.

Initially conceived as a rooftop extension to a pre-existing home, this Rotterdam-based design project evolved into the construction of three miniature housing units. Known collectively as Didden Village, the bright blue houses are separated by a series of plazas, streets and alleys, which have developed into a rooftop communal space.

The transformation of a disused rooftop aimed to provide a building solution for the densification of Rotterdam while retaining a sense of community. The mini-village feel is further enhanced by the addition of trees and communal spaces, including benches, tables and trees.

Each ‘house’ consists of a compact interior, which serves as a communal room, bedroom and bathroom. Skylights allow people to make the most of natural daylight, while spiral staircases attach each ‘house’ to the main building below them.

Challenged with the design brief of creating an additional 100 homes in a pre-existing block of apartments, MVRDV expanded on their Didden Village project by designing a series of parasitic structures that extend outwards from the surface of the original building.

The result is a series of spacious living units, which appear to be glued onto the surface of the pre-existing structure. Allowing each of the new units to protrude outwards meant that additional balconies and larger windows were included in the design scheme. The decision to attach each unit in this manner allowed for the exterior communal space to remain intact.

Designed by Stefan Eberstadt, the Rucksack House is a parasitic structure that allows its owners to create additional rooms in a pre-existing space through the addition of strap-on extension units.

Each structure is mobile and light with a minimalist, spacious interior. Owners can make the most of natural light during the day through its abstract windows. There’s no reason to stop at one either, as multiple structures can be stacked above, below and beside each other.

The ‘Chambre Suspendue’ is a minimalist studio space designed by NeM Architectes as a solution for cramped living conditions. A gap between a row of houses offered the opportunity for the architectural firm to construct an elevated studio space fit for one with just enough room beneath it for a car space.

The interior has been designed with ample storage and surface space, while its large window provides natural light and a panoramic view of the city. The exterior is extended with a small balcony, which provides space for potted plants.

Included in the 215 square foot interior is a separate bedroom, which is elevated from the living area, providing a clear-cut division between each room. Though wall surfaces in the bedroom are restricted, a skylight provides plenty of light during the day.

The architects of this home were faced with the challenge of building a modern apartment while retaining the facade of a pre-existing historical structure. As with most parasitic structures, instead of knocking down what was already there its designers made the most of what they had by building up.

The available wall space has been exploited with floor-to-ceiling windows, which takes advantage of the natural light during the day. Due to space restrictions, architects created an open-plan living room and kitchen area, which extends outwards from the surface of the pre-existing building.

The property’s bedroom is located in the floor above and, though space is limited, its designers have made room for an attached bathroom and dressing room. A terrace, which is accessed through the bedroom, has been constructed above the living area.

Meanwhile in Finland a series of structures have been attached to the top of a disused iron foundry in a bid to create a combined housing and business centre. The complex consists of three independent units, in which 45 new homes, cafes and shops have been placed. Link Architects chose to retain the old factory space beneath to form a connection between the modern city and and its industrial past.

London's historic skyline is slowly being surrendered to a sea of shiny new skyscrapers, so it’s refreshing to see architects using parasitic architecture to create spacious housing solutions in overcrowded environments.

Nestled on top of a Victorian warehouse in Central London, Tonkin Liu’s steel structure looks more like a greenhouse than a conventional home. Inside, sliding doors are used to create spatial dividers between its six bedrooms and open-plan kitchen/living area, which are spread over a compact space totalling 2,800 square feet.

Wall-to-wall windows allow its inhabitants to make the most of natural daylight, while showcasing stunning views of the City of London’s skyline. Hanging plants on the exterior of the apartment provide natural shade, while creating an indoor-outdoor environment.