The Elephant Cage

Project Brief

Portsmouth is nearly flat and is an island city that is extremely vulnerable to coastal inundation from climate change induced rises in sea level. It has the highest population density in the UK after London and its open space is largely provided along the seaside or on the sea. The city faces risks, also emerging elsewhere in the UK, which are very similar to those equally found in The Netherlands.

  • A pressing need exists to reinforce the costal defences of Portsmouth to address climate change induced rise in sea levels
  • Extensive investigations have already been commissioned to appraise the problem
  • In places the existing sea defences are now reaching the end of their life expectancy, so a replacement solution is imminently required
  • Recommendations and draft proposals have now been prepared within the constraints of the Governments budgetary allocation. These proposals have advanced to HM Treasury Green Book stage 2
  • Public consultation in 2015 highlighted significant deficiencies with these proposals most specifically along the unique, famous and popular Southern frontage of the island
  • This frontage extends from Old Portsmouth and Southsea common, which is a large public park in the west, along to Fort Cumberland, at the entrance to Langstone Harbour, in the east. There are in excess of 40 listed monuments along this front
  • The area in Southsea immediately behind the frontage is used, for example, for grandstanding of the Ben Ainslie bid in the Americas Cup trials and annually for the Victorious Festival which is now one of the largest summer festivals in the south east. It was also famously used historically for the Fleet Reviews. It has lots of character but despite its delights is in much need of some sensitive well considered seaside regeneration
  • Public objections to the recommended proposals focused on the sea defences that would separate the promenade, beach and sea from Southsea common and the city to the north. In many parts a wall exceeding 2m in height would be apparent from the landside severing the city from connecting fluidly with the coast and blocking views of the sea
  • Among other consequences the entrance to South Parade Pier will be blocked, and the position of many historic monuments will require address
  • Better more integrated solutions are being sought to add value to this public investment, leverage private engagement and gain popular public support from better interrogation of the design issues. The challenge is to posit, through this design research competition, ambitious propositions through strategy and detail which can advance knowledge and inform practice in this location, whilst informing on-going UK wide design strategies that address climate induced rises in sea levels in other seaside locations
  • The aim is to achieve a better design synthesis between the coastal defences with landside public realm improvements that can enhance the environment, amenities and economy through better integration of the infrastructure
  • The Elephant Cage programme will engage with these opportunities to develop solutions from the holistic integration of engineering, architecture, landscape, ecological and economic issues to benefit the city, its public realm and amenity

The Promoters

The promoters of The Elephant Cage are:


The proposals developed at the Portsmouth Elephant Cage will be widely disseminate to stakeholders, both locally and nationally, this will include public exhibition in Portsmouth immediately following the event, with our media partners in national publications, and through web dissemination. The event will also be written up in English and Dutch by the University of Portsmouth School of architecture and Architectuur Lokaal. Competitors will also have opportunity to present their outputs to local stakeholders, its representatives and the city authorities.

Budget and Costs

The current coastal defence designs have a budget of approximately £60m. The allocation for this basic works remains largely fixed. However the projected central government funding excludes areas of public realm to the immediate rear of the sea wall.

The generation of ideas and visions focused upon the public realm relating to the sea wall are a unique opportunity for design research, knowledge exchange and networking to inform progressive development. A challenge in this competition therefore is to also reflect upon the business case for financing the public realm design issues, and exploring how benefit and value might best be achieved in the context, for which there is currently no budget.

Project CompassArchitectuur LokaalUniversity of Portsmouth School of Architecture