BAM Design is also the masterplan architect for the 45-acre business Park, which was formerly farm land.
Unit five will be a 10,000m2 industrial warehouse and 750m2 office which is being taken by Bio Pure Technologies, part of the high-end pharmaceutical pipework specialist Watson-Marlow.
The building will be ready for production in 2022 and follow the creation of three other units by BAM at the site.
The latest project is the largest of the plots to be developed so far.
The development of the Portsmouth City Council-owned business park began in 2016.
John Rixon, Commercial Manager for BAM’s South East team, said:
“This is an interesting appointment for us because Portsmouth has used Procure Partnerships, and it is a direct appointment for us.
“Our enabling works across the whole of the business park put us in an excellent position to compete for each unit, but we have to prove the quality and value of what we do each time.”