Langstone Coastal Defence Scheme

Havant Borough Council (the council) is seeking a suitably qualified and experienced construction contractor for the construction delivery or a flood and coastal erosion risk management (FCERM) scheme at Langstone, Havant, UK (the scheme).

The scheme covers approximately 1km of coastline in Havant, extending from SU 71655 04962 in the west to SE 7191 0501 in the east. The alignment protects the largest number of properties and critical infrastructure including the A3023 (the only highway access to Hayling Island) and a number of heritage assets. This includes 53 residential and 4 business properties which will be better protected through implementation of this scheme. A further 6 residential properties not currently at risk, but which will become at risk by 2040 due to climate change will also be better protected within the 50-year lifetime of this scheme.

The frontage is is popular with locals and visitors due to its unique setting between two harbours, and is an important area for cultural heritage, with six listed buildings and two Conservation Areas. There is a network of footpaths, which also features the historic Wadeway, Solent Way and Hayling Billy Line (which also doubles as a cycle route). There are also two pubs in Langstone (the Royal Oak and the Ship Inn) and the harbours are popular for watersports.

The scheme involves the construction of 1km of new, continuous defences which consist of earth raising, flood embankments, reinforced concrete flood walls, sheet-piled walls, flood glass, flood gates and demountable defences.

The history and development of the scheme can be found at: https://coastalpartners.org.uk/project/langstone-coastal-defence-scheme/.

Delivery of the works will be managed using an NEC4 Engineering and Construction Contract (ECC), utilising Option C - activity schedule with target cost. The contract will be managed by an accredited NEC4 Project Manager and administered using CEMAR software, hosted by the council.

The contract is due to commence on 1st May 2026 and will run for a period of 2.5 years, with completion no later than 1st December 2030.

Following contract commencement, the council will engage the contractor to work collaboratively with the aim of reducing the costs, increasing buildability, mitigating risks, and making the programme more resilient where possible. This stage of Early Contractor Involvement (ECI) is incentivised in clause X22 of the Contract Data.

The NEC4 ECC option C is a target cost contract with a pain/gain share mechanism, whereby any savings (gain) or additional costs (pain) are shared between the council and the contractor. The pain/gain share mechanism is set out in the contract data and is summarised below:

Where the final cost is:
- Less than 80% of the target cost, the Contractor's share is 20%
- Between 80% and 120% of the target cost, the Contractor's share is 50%
- More than 120% of the target cost, the Contractor's share is 100%

The value of the contract is estimated to be in the region of £12million to £14million excluding VAT.