Q. How often should I expect my co-op maintenance charges to go up? What's a normal increase and why? Does it ever go down? A. Expect your maintenance charges to go up every year or two, say our experts, and expect the increases to be well above inflation. Maintenance fees cover the costs to run the building, and "in recent years a big challenge facing co-op boards has been rising fuel and real estate tax costs--which are rising faster than overall inflation," says real estate appraiser and market analyst Jonathan Miller of Miller Samuel Real Estate Appraisers & Consultants.