The project became significantly delayed after 400 tonnes of asbestos were uncovered within the building and extensive additional ceiling works required specialist heritage planning permission.
This led to a dispute between Styles & Wood and the client resulting in the termination of the contract for the project earlier this month.
A new timetable and programme for the £11m category A fit-out has been agreed with Caddick with the grade II listed building now due to be completed next summer.
The programme of refurbishment across the 350,000 sq ft of commercial space will include complex remedial work, façade repairs, as well as renewal of more than 50% of office ceilings.
Cast iron drainage systems will be relined and building services replaced.
Caddick will also instal five new lifts and refurbish eight existing lifts.
Caddick Construction senior project manager, Mark Walker said: “We are working to quickly re-engage with the existing supply chain and are confident of a seamless handover to HMRC as existing anchor tenants early summer 2020.”
Brian Rabinowitz of India Buildings Development, added: “The works are being delivered within a very short timescale and will be completed to a very high specification; providing a modern office environment that is sensitive to this important historical building.”
Principal designers on the projects are Falconer Chester Hall, with engineering works by Curtins Consulting.