You can first ownload Booklet 6 click here to see the requirements & procedures for the application.
As your husband is not working in the civil engineering field in the past 12-18 months, he cannot nominate civil engineer as his skilled occupation and canot enjoy the 15 bonus points given to civil engineer which is currently an occupation on demand.
But he can still apply as a teacher which is also a 60 points occupation. Then he need to check whether he can get 120 points to pass the point test, taking into account the age, working exp., English requirements etc.