The new Teesside office aims to grow by 400 units a year over the next three years. It follows the West Midlands region which was opened 18 months ago.
Further expansion plans were set out as the private house builder announced a 13% increase in completions to 1,684 homes in the first half of this year.
It also said that interim pre-tax profit had jumped a fifth to £55m while operating margin remained stable at 20%.
Miller said forward sales were up 7% on last time to a record £368m.
Chris Endsor, chief executive, said the house builder was on track to achieve its targeted 4,000 homes by 2021.
“Customer demand has remained strong set against a backdrop of competitive mortgage rates but just as importantly an overwhelming need for many of our customers to acquire a new home.
As a further sign of our confidence in our regional markets, we invested significantly in land in the period, acquiring 12 sites at a cost of £94m.
“Our new Teesside region will be launched in the second half of this year, becoming fully operational from the start of 2020.”