Recently, there were a number of e-mails back and forth between the folks I work with at FDE wondering how one might go about projecting maintenance costs for a facility. Since that question comes up every once-in-a-while in training classes, I thought I would share some of the information I have in this blog post.

In terms of general information, the 2007 ASHRAE Applications Handbook has a pretty good chapter discussing what you need to think about (Chapter 36;  the 2007 edition is the most recent edition of the Applications handbook). There is not a lot of hard data but they have included a table in that chapter that contains the results of some studies ASHRAE did that are probably a good starting point for anything you might be doing and can be modified by the other criteria in the chapter.

If you go back a couple of editions of the Applications handbook you can find the source of the earlier study cited in the table illustrated above along with an equation for calculating maintenance costs for an office building. It’s fairly straightforward and I actually built that into a spreadsheet at one point.

I have the spreadsheet posted in Google Docs if you want to take a look at it and use it as a starting point for a spreadsheet of your own. I’ve even added some instructions so it will hopefully make sense to someone besides me and so you know the limitations.

The ASHRAE Applications handbook also includes a service life table that comes in handy, at least as a citable source when you are trying to compare things like package roof top equipment with equipment installed in an equipment room, etc.


I actually keep a screen shot of both tables in a little “Tools” folder on my desktop so I can get to the information quickly when necessary.

Related to these resources are publicly available online data bases that ASHRAE has started which are gathering service life and maintenance cost information as you read this. I believe the maintenance cost data base actually seeded the maintenance cost information in the newer study cited in the maintenance cost table above.

Both are public domain and seem to be gradually growing. They allow you to filter the results by a number of factors such as Region, State, Function, etc. Here is what I got from the Service Life data base when I queried it for Air Distribution Systems with the other fitlers set to “All”.


Here is what I got from the Maintenance Cost data base for a similar query directed at Labs.


The other thing I use to estimate maintenance cost is the R.S. Means Facility Maintenance and Repair Cost database. It’s not perfect, but again, is something to cite and is better than nothing and a good starting point in a lot of instances.

I annually purchase the electronic license for this title as well as and the MEP costs title; the total for both probably runs $500 – 600 a year. That can be a bit spendy, but in my case, I always have projects I’m doing that justify the cost so I build it into the project budgets.

I used to just buy the paper versions every couple of years and tweak the numbers for inflation, but lately, about half the time, I’m on the road when I need the information so carrying a CD around (they won’t let you install it so you can run without a CD) is a lot easier than a couple of inches of paper.

Unfortunately, if you go the CD route, you can’t just buy it once and use it a couple of years and tweak the numbers for inflation like you can with the paper copies. There is something into the software that locks you out of the CD on the anniversary of your purchase date (something that I realize one might find to be really annoying) but that’s how it works.

I suspect that there are legitimate reasons for making you renew the software that are related to keeping everything current, including things like accurate adjustments for inflation, new information, and regional pricing differences, all of which make the renewal fee well worth it for “power users”.

For the stuff I do, I just scratch the surface of the software capability. But still, the bottom line is that I can usually use a project to pay for the license and the CD is much more convenient than annoying so I go that route. Besides, I suspect I save the cost of the CD in the over-weight baggage charges I would incur if I dragged all the paper copies around with me.

David Sellers
Senior Engineer – Facility Dynamics Engineering

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  1. M. Mullen says:

    Mr. Sellers,
    On behalf of ASHRAE TC 7.8, Owning and Operating Costs, who is responsible for both the referenced handbook chapter and the ASHRAE Operating and Cost Database you reference in your article, I want to say thank you for your great article. Our committee has worked hard on updating the information your referenced and are extremely pleased to see you are applying it regularly.
    I would like to point out that the database is available to anyone at the ASHRAE website. Furthermore, it it intended to be an interactive website as we are encouraging others to input their data into the database. The more data we obtain, the more accurate the information will be. So we hope other building professionals will avail themselves of the opportunity to use the database as well as grow it.
    Thank you.
    Matthew E. Mullen, P.E.
    Current TC 7.8 Chair

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