Preliminary fixture count estimates

[smp123069]

I'm trying to find a table providing preliminary estimates for sanitary sewer fixture counts. Ideally it would include single family homes (possibly with a range of square footage or bathrooms)and apartments (w/ range of 1,2 efficiencies). Does anyone know where I can find a table of this sort? I am familiary with the fixture unit values per fixture or group. I'm hoping that somebody has published a table to use for this preliminary estimate prior to doing the actual final fixture counts.

Also, are the fixture counts for drainage fixture units the same as for water demand fixtures? or are these two separate fixture counts?

 

[PEDARRIN2]

I am not sure there is a table that would outline such groupings. My experience is that you just count the fixtures and add up the values. You try to combine them into groups and that would make it easier.

The drainage fixture units and the water demand fixture units are different. For example a public flush valve water closet has 6 DFU's and 10 WDFU.

Hope that helps.

 

[Resercher]

You use fixture units count only if you do individual buildings. However if you are dealing with city sewer or big housing complex you use a different uproach. If you use the fixture count method you will double or triple the amount you are suppose to get because the diversity factor between the different facilities is not accounted.

In the appendix of UPC, I think is on the illustrations manual, there is a table giving water demand for different facilities. ie for housing they give per person, for hotels they give per unit, for hospitals per ped, for supermaket per square feet etc.

You get the total of all these water demands. The sewer is 80% of that total water consumption.

What goes in comes out, except of course for the cooking, drinking, irrigating etc

 

[Drazen]

You have two available books for such estimates.

"Nacional Plumbing & HVAC Estimator" by Craftsman Book Company,
and "RSMeans Mechanical Cost Data" by RSMeans Company. I posess both of these books, but slightly prefer RSMeans, which is more expensive.

It has just data you need: for example, typical bathrooms with all typical materials, and average of general rough-in piping that can be related to one bathroom, so you can make labour and material estimates by counting number of bathrooms, kitchens etc. This is very good for preliminary estimates, but you need to track your actual costs for several projects and find some realistic modificator to book data, book is just a guide and good for start; your real data collected over time is the most important element for your business. Even then, book structure can help you to collect data in adequate manner that fits your needs.