Portsmouth's construction market sits at the intersection of defence infrastructure and city regeneration, creating two distinct but complementary pipelines for local subcontractors. The dominant employer is the Royal Navy estate at HMNB Portsmouth, where KBS Maritime (the joint venture between KBR and BAE Systems) manages a six-year building investment programme running over several years. The programme is refurbishing five operationally key buildings including the Grade II-listed Sail Loft, the Cochrane Building and The Wardroom. Works run through to at least December 2026 on RIBA Stages 2 and 3, with design and build contracts to follow. This programme alone draws a steady supply chain of groundworkers, bricklayers, plasterers, joiners and specialist restoration trades from across Hampshire and the wider south coast.
Away from the base, the Royal Marines Museum at Boathouse 6 in the Historic Dockyard is under active construction, a £9.5 million scheme due to open in summer 2026. Separately, Portsmouth City Council is advancing the City Centre North regeneration, targeting the former Tricorn and Sainsbury's sites with a master developer appointment in progress and first homes expected in late 2026. The former Debenhams site on Commercial Road is also moving towards a 2026 construction start under a national development partner. Both schemes will generate significant sub-trade demand in groundworks, concrete frame, fit-out and finishing trades. Subbies working across these projects often operate informally with multiple main contractors and are among the most likely to be deducted at 30 per cent (the unregistered rate) rather than 20 per cent, underscoring the value of CIS registration and proper accountancy support.