Before revision: In the construction industry, the 1:5:200 rule (or 1:5:200 ratio) is a rule of thumb that states that if the initial construction costs of a building is 1, then its maintenance and operating costs over the years if 5 , and the business operating costs (salary of people working in that building) is 200
After revision: In the construction industry, the 1:5:200 rule (or 1:5:200 ratio) is a rule of thumb that states that if the initial construction costs of a building , the operating costs over the years if 5 , and the business staffing costs over 20 years could be expressed by the ratio 1:5:200.years