Spanish architects José Selgas and Lucía Cano have revealed their proposal for the 15th Serpentine Pavilion in London – a "chrysalis-like" structure made from colourful see-through plastic.

Occupying a space in front of the Serpentine Gallery in London's Kensington Gardens, the temporary pavilion is envisioned as a series of connected spaces of different shapes and sizes, made from a double-layer shell of opaque and transparent fluorine-plastic fabric (ETFE) in an array of colours.

The plastic will filter the daylight like a stained-glass window, casting coloured light into the interior spaces, which include a central gathering area and cafe. An evening image provided by the architects shows the structure lit from within.

"We sought a way to allow the public to experience architecture through simple elements: structure, light, transparency, shadows, lightness, form, sensitivity, change, surprise, colour and materials," said the Madrid-based architects.

"The spatial qualities of the pavilion only unfold when accessing the structure and being immersed within it. Each entrance allows for a specific journey through the space, characterised by colour, light and irregular shapes with surprising volumes."

The fabric will be arranged in panels, with strips of material woven through or wrapped around parts of the structure like webbing. The double shell will create a corridor between the inner and outer layer of the pavilion, and visitors will be able to enter through multiple openings in the sides.

SelgasCano are the first Spanish designers to design the temporary pavilion, which is commissioned and built each year by the Serpentine Gallery in London's Kensington Gardens.

The duo are known for combining new technologies and synthetic materials with an interest in the natural world, and often use bright colours and transparent surfaces in their projects.

Their own studio is a see-through woodland tunnel, and a recently completed office refurbishment in London features an orange plastic seating area that bulges out of the facade.

"In keeping with their reputation for playful designs and bold use of colour, SelgasCano's structure will be an extraordinary chrysalis-like structure, as organic as the surrounding gardens," said Serpentine Galleries director Julia Peyton-Jones and co-director Hans Ulrich Obrist.

The Serpentine commissions a different architect to create the pavilion each year, offering them the chance to create their first built structure in England.

Previous pavilion architects have included Peter Zumthor, Zaha Hadid, Sanaa, Herzog & de Meuron, Frank Gehry and Jean Nouvel. Last year's boulder-like pavilion was created by Chilean architect Smiljan Radic.

"We are very much aware of the pavilion's anniversary in our design for the 15th annual commission," said SelgasCano. "The structure therefore had to be – without resembling previous Pavilions – a tribute to them all and a homage to all the stories told within those designs."

The 2015 Serpentine Pavilion will open on 25 June and close on 18 October. It will host a number of parties and public talks, as well a series of evening events sponsored by fashion brand COS. These will include new commissions by artists Jesse Darling, Fleur Melbourn and Marianna Simnett.