Vigar joins from Willmott Dixon where she was Strategic Business Development Manager.
Vigar will be responsible for working with existing clients in the public sector and will look to seal new deals in developing markets including community regeneration, science and technology, defence, energy and rail.
She said: “The business is entering an exciting new phase and I am looking forward to working with Chris Webster and the team.
“Miller Construction is a highly respected player in the construction industry, which has the ability to provide an integrated offer to the market including investment, development, construction and maintenance of buildings.
“I am looking forward to my new venture which will see me working with key clients particularly in those areas that most need an economic boost to unlock developments.”
Chris Webster, Chief Executive, Miller Construction, added: “We are delighted that Karen has joined the team.
“Karen has a proven track record in building and maintaining key relationships with clients which will enable us to strengthen our existing client relationships, in addition to developing new opportunities.
“Karen will manage our account relationships in the public sector and will work with the senior management team to identify new and emerging markets where opportunities present themselves.
“Her role and responsibilities will complement those of Chris Houchin, our National Business Development Director who joined the business earlier this year, to focus on our presence and position in the private sector. We believe Karen will make a valuable contribution to the growth and development of our business.”