Competition: to celebrate 15 years of the Serpentine Gallery Pavilion, Dezeen has teamed up with fashion brand COS to offer readers the chance to win tickets to a talk with the gallery's co-directors Julia Peyton-Jones and Hans-Ulrich Obrist.

Congratulations to the winners! Luke Weston, Annabel Ward, Susana Sousa Egido, Jack Morgan and Timmy Lum.

The Serpentine Pavilion Retrospective: 15 Years On talk will take place on 7 October 2015 at the COS store in London's Spitalfields.

Dezeen editor-in-chief Marcus Fairs will chair the discussion, which will revolve around the coveted architecture commission given to an architect that has not yet built in the UK each year.

Peyton-Jones and Obrist will speak about the history of the project and highlights from the past 15 years, and answer questions from attendees.

As part of the anniversary, Dezeen has also created a series of movies telling the story about each pavilion – from the early structures by Zaha Hadid and Daniel Libeskind to this year's design by SelgasCano.

COS has partnered with the Serpentine Gallery Pavilion's Park Nights talks programme for the past three years. For 2015 the brand released a limited-edition backpack to coincide with the pavilion launch, and last year it produced pairs of shoes.

The COS Spitalfields store is located at 28 Brushfield Street, London E1 6AG. For the event, a reception with drinks and canapes will start at 6pm, and the talk will begin at 7pm.

Five winners will each receive a pair of tickets to the event. Travel and accommodation are not included in the prize.

This competition has now closed. Winners will be selected at random and notified by email, and their names will be published at the top of this page. Dezeen competitions are international and entries are accepted from readers in any country.