Architecture, engineering, and environmental consulting firms have increased their hourly billing rates an average of 16% over the past five years, according to Natick, Mass.-based ZweigWhite's report titled “2004 Fee and Billing Survey of A/E/P and Environmental Consulting Firms.” Executives from 150 firms provided information on their billing rates, fee structures, staff chargeability, and billing practices for 29 employee positions. For this survey, each firm provided the industry standards for the billing rate of each level of employee in its firm. Results showed electrical engineers with one to five years of experience charge a median of $80 per hour, and half have billing rates between $72 and $92 (Table below). Senior electrical engineers have a median billing rate of $100 per hour, and a quarter charge $118 or more per hour. Designers and senior planners with more than five years of experience increased their hourly rates by as much as 35% while electrical engineers reported the lowest percentage increase of less than 10% over their 2000 rate. The survey also found that consulting firms often charge clients for their employees' time by the hour under time and materials contracts. They may even measure their profit and loss under lump sum or fixed price contract jobs by charging time against a project at billing rates.