The base in Gateshead was made possible by TEP’s recent success in winning a four-year national green estate consultancy for Homes and Communities Agency.
The practice manages sites for the agency including greenfield sites to large derelict hospitals.
"A multitude of management aspects are covered including landscape, security, tree risks, trespass, water safety, and biodiversity," office manager Alistair McGregor.
"Work ranges from landscape management of benign plots to more involved work on derelict sites."
He said the agency acquired a lot of land from the old regional development agency and work included everything from large scale landscape management and security to handling issues of safety and tree stock for which it had a bespoke database of all agency trees.
TEP provides landscape, arboricultural, ecological, design and planning services to clients including house-builders, councils, utility companies and estate owners.
Its head office in Warrington has 70 staff, Milton Keynes six and Gateshead five, but the latter aims to recruit one more professional.
McGregor said: "If things go well we would hope to expand but right now we are consolidating our workload. It would be good to attract more work in ecology, arboriculture planning and design."
The HCA is the national housing and regeneration delivery agency for England.