As head of a former grant-maintained school in Lincolnshire, she has plenty of experience with private companies and says: "They are not the big bad wolf."
The school, Monks Dyke Technology College, in Louth, has a new art and science block and is constructing a performance and broadcast centre. She worked closely with architects to make sure she got exactly what she wanted.
She said: "We looked at the curriculum side of things and they have interpreted that so the architecture is suitable.
"I suppose because I have experience in this field there is no fear of the unknown. LEAs often lack expertise in certain areas and thee is too much bureaucracy.
"It is about working with the community you serve and being able to make your own choices.
"In the private sector, people come to you with expertise, not dogma.
"In the future I see some sort of regional set-up and I don't think the LEAs will exist."
Mrs Williamson said: "I'm not directly critical of LEAs because I think their problem is that they are increasingly squeezed for resources and that limits what they can do.
"But working directly with private companies enables me to have control. I am the one writing the cheques and that means I can make sure I get exactly what I want.
"And at the end of the day, we are extremely pleased with the job the architects have done for our pupils."