Construction Equipment
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I have a school project (Construction management) that involves the estimating of the electrical cost for a building addition. I can do the fixture counts, equipment hook ups, box counts, switches and etc. I cant figure out how much wiring would be involved. from the blueprints, is there a way to measure (estimate) the lf of wiring? this is a school building so there are mostly medsize room and hallways. any help would be great. I remember something about the “homerun” count from when i was a laborer, but could i figure 1 line around the room with a line for fixtures or something like that. doesnt have to be perfect by any means.
oh, i will be using the RS means to calculate labor and material costs
sorry, not looking for a price, just how an estimator would do a very rough estimate. I can count panels, fixtures, hvac hookups ,switches and duplex etc, i am just not familiar with how to read circuits (or estimate the length of wire to connect all of the above). i can figure out the gauge and type of wire, just not the lf.
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Construction Information Services.
Construction Management Related Software Including Scheduling, Estimating And Reporting Software And EBook(R)s As Well Public Interest EBook(R)s.
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Tags: commercial, electrical, Estimating
You aren’t giving anything even close to enough info for an estimate.If you have set of plans you would have to go to the electrical specs. and find out what needs to be included.
ie; additional panels,increased service from electric co., computer class rooms, fire alarm, wiring in conduit…….the list goes on and on, your not just adding a few lights and outlets., what about HVAC that all requires elect.
Good luck!
Figure out the load for each “room”. Remember the vacuum cleaner rule. Figure out where the source is (panel or sub).
Then run each line (including ups&downs) to each outlets, add 2 feet at each outlet – add extra afterwards.
Not sure with school codes for electrical, but say for kitchens, you need 2 sep circuits for the top, circ for fridge, circ for DW circ for GarDisp.. etc. Each circuit starts a home run.
You can probably find circuit requirements online somewhere.. But…
If it really doesn’t matter… Put an outlet every 4 feet on the teacher wall. Use 2 circuits and stagger it.
Use two more circuits and stagger them (vacuum) rule around the class room (maybe 2 for each wall). (New schools use WAY more power, elect smart boards, laptops, comps, etc).
Just get the drawing, imagine what you’d want – draw the runs and add it up, otherwise use the plans..
Just think, each circuit comes from the panel, over to the room, to the first outlet, then the next, (dont Y or branch out), and then the last circuit. It’s clean, simple and easy.
Wires comes easily purchasable in the following lengths from your favt box store.
50,100,250,1000
One way to go would be to identify the circuits in each room.
Measure distance between outlets & switches , add 12″ for each outlet or fixture & each 90deg turn if wire is to be run in conduit.
If you have some idea of route wiring will take, account for going up over cielings or under floors to the “home run” to the service panel for each circuit , allow for a 6′ tail at breaker location & then add 10%.
Assuming everything will take (or might be required to take )
perimeter routes w/ 90deg turns & dressing the conduit on walls or racks you should be be safe.
Some est runs will be long & some short , but it evens out.
Might be a good idea to show how you arrived at estimate on your worksheet.
Might not be the “only ” way to estimate , but it shows you gave it some thought.
Best regards
I am an electrical contractor. I use the actual dimensions to estimate the wire. Copper wire is much to expensive to just take a guess. Start with the home-run and add the LF as you go. 1 circuit at a time. On a large commercial job I might figure a median length circuit and then use that figure for all other branch circuits.