The streamlining is part of a business restructuring that saw north east and south west regional managing directors leave the business last month.
The decision will fuel industry rumours that further closures could be planned in the south west region following the departure of regional boss Peter Whitmore.
Under ongoing plans to reshape the construction business Durham operation activities will move to Leeds.
The new national structure will see Morgan Sindall operate across four enlarged regions with David Smith and John Homer taking on wider regional responsibilities.
A spokesperson for Morgan Sindall said: “In parallel with continually securing new projects, we do, in the course of prudent business management, regularly review the scale of our operations, including our office network, to reflect market conditions.
“As part of this, we recently announced that our Durham office will be closing by the end of October, a move which follows our decision to focus the management of our operations across the North East of England from our Leeds office.
“This enables us to keep our cost base as low as possible to ensure that we can continue to provide our customers with outstanding quality and value.
“It will have no impact on our current projects and our commitment to develop the pipeline of new business across the North East which remains as strong as ever.”
He added: “Despite challenging trading conditions, our construction business across the south of England and Wales has secured projects worth over £115m in the last month alone – these include Slough LABV, an office design and build on Chancery Lane and Ynysboeth Primary School.
“In addition, we continue to win new contracts, and both retain and secure new long-term framework agreements, across our entire business.”