Does anyone have any shortcuts and/or advise to estimating branch circuit wiring for commercial structures. I have no problems counting all the devices and fixtures. But when it comes to figuring out the quantity of conduit, wiring, mc cable, junction boxes etc needed, it takes for ever to figure it all out especially on multi-level commercial projects. It takes me hours to "ESTIMATE" those quantities and I wonder if I am anywhere near accurate, not to mention pushing my estimate deadline. Please help.
Estimating BCW
- Thread starter darrin
- Start date
- Status
highkvoltage
Senior Member
Re: Estimating BCW
Software and scalex tool.
Software and scalex tool.
tx2step
Senior Member
- Location
- North Texas, DFW area
Re: Estimating BCW
Darrin -- Please describe how you are currently taking-off the branch rough-in and wire.
What is your procedure, what steps do you take, and in what sequence?
Darrin -- Please describe how you are currently taking-off the branch rough-in and wire.
What is your procedure, what steps do you take, and in what sequence?
Re: Estimating BCW
tx2step
When I am figuring receptacles and the like:
1. Once I have the receptacle count I figure that each receptacle will take a 4sq bracket box, a plaster ring, receptacle and cover plate.
2. For the BCW, if I am allowed to use MC cable, I will painstakingly figure out how much each room/office etc will require.
3. Then I figure out how I will get the required circuits to each individual room from the panel. This is what usually takes me the longest time to figure. Most of the time, I will figure on setting a 4sq j-box in each room, then run 3/4 conduit back to the panel picking up each room along the way. Then of course figuring out how much wire needed to get the necessary power to each room.
I do the lighting is the same fashion:
1. Each room gets a 4sq bracket box, plaster ring, switch and cover plate.
2. Each room gets a 4sq-box for power that is typically routed back to the panel via 3/4 conduit.
What do you figure for connecting your fixtures to for picking up it's respective BCW? Usually I will figure on setting a 4sq next to every fixture and running conduit to each? Usually end up being a little too much and takes up a lot of time. Any simpler methods?
tx2step
When I am figuring receptacles and the like:
1. Once I have the receptacle count I figure that each receptacle will take a 4sq bracket box, a plaster ring, receptacle and cover plate.
2. For the BCW, if I am allowed to use MC cable, I will painstakingly figure out how much each room/office etc will require.
3. Then I figure out how I will get the required circuits to each individual room from the panel. This is what usually takes me the longest time to figure. Most of the time, I will figure on setting a 4sq j-box in each room, then run 3/4 conduit back to the panel picking up each room along the way. Then of course figuring out how much wire needed to get the necessary power to each room.
I do the lighting is the same fashion:
1. Each room gets a 4sq bracket box, plaster ring, switch and cover plate.
2. Each room gets a 4sq-box for power that is typically routed back to the panel via 3/4 conduit.
What do you figure for connecting your fixtures to for picking up it's respective BCW? Usually I will figure on setting a 4sq next to every fixture and running conduit to each? Usually end up being a little too much and takes up a lot of time. Any simpler methods?
tx2step
Senior Member
- Location
- North Texas, DFW area
Re: Estimating BCW
Darrin -- It sounds like you are dealing with plans that only show the locations of the lights, receptacles, switches and other devices. None of this stuff is already circuited out, right?
If that's the case, then the only way I do it is:
1. Count and color (as you count) all of the fixtures and devices.
2. Circuit everything out, drawing in the conduit routing and circuiting as I would do it if I was installing it. You essentially have to design the installation.
3. I still am doing estimates manually (I don't do that many right now, so I can't justify software right now. When I need it, I'll buy it.). So, I use a rotometer of the correct scale (mine are old, look like a pocket watch with a little wheel and a reset button, and you roll them along the conduit route to measure the footage of the conduit.)
4. With a click counter in my left hand and the rotometer in the right, I scale off all of the 1/2" with 2#12. I click the counter once for each run between J-Boxes. That gives me the number of connectors (count X 2), plus 20'/count of conduit + wire if I am looping up and down. I add this to the horizontal length from the rotometer. I color all of this conduit one color so I can see what I took off as 1/2" EMT with 2#12s.
5. Same process for 1/2" with 3#12s, then 4#14s, and all other combinations. I color each combination with a different color.
Boxes, rings, covers, devices, wirenuts, fasteners etc. all derive from the lighting and device counts. Straps, fasteners and couplings and wire come from conduit footages. (sort of a modified assembly take-off method)
I take all of the branch off for the job using something like this method, with variations for different wiring methods.
For feeders, I have feeder take-off sheets that I do by panel by circuit. That way, I don't miss any feeders. It is a "from" "to" system. I start at the transformer and go to the last panel, coloring off stuff as I go.
It's hard to describe, but easy to do with practice. Pretty accurate, but not real fast. Not that slow, though, if you learn good habits and practice.
I haven't taken any estimating classes in a long time, so there are probably better methods and ideas around now.
I'm sure that using estimating software with direct input measuring devices will be much faster. But even when I add this stuff, my general take-off procedure will remain the same until someone shows me a procedure/sequence that works better.
When I completely finished, if I do the project, then I give the color coded drawings and various take-off sheets to my job electrical superintendent.
If he has better ideas, then we change the take-off accordingly. When we agree and everything is double-checked, then the materials are ordered -- they match the drawing layout.
We don't really end up making many field changes after he is on-site, since we are pretty thorough in the planning stage. We look at all of the drawings -- architectural, structural, mechanical, details, etc. I'm big on preplanning -- you catch a lot of mistakes and conflicts before they happen.
He takes this info to the jobsite with him and has it to refer to during construction. He pretty much puts it in according to our plan. That way, all of the materials needed work out, and hardly anything is missing. Everything fits, with very little left over, and very few trips to the supply house.
This probably seems slow and tedious, and it probably is. But I hardly ever run over on materials or labor -- I almost always stay within estimated cost.
Darrin -- It sounds like you are dealing with plans that only show the locations of the lights, receptacles, switches and other devices. None of this stuff is already circuited out, right?
If that's the case, then the only way I do it is:
1. Count and color (as you count) all of the fixtures and devices.
2. Circuit everything out, drawing in the conduit routing and circuiting as I would do it if I was installing it. You essentially have to design the installation.
3. I still am doing estimates manually (I don't do that many right now, so I can't justify software right now. When I need it, I'll buy it.). So, I use a rotometer of the correct scale (mine are old, look like a pocket watch with a little wheel and a reset button, and you roll them along the conduit route to measure the footage of the conduit.)
4. With a click counter in my left hand and the rotometer in the right, I scale off all of the 1/2" with 2#12. I click the counter once for each run between J-Boxes. That gives me the number of connectors (count X 2), plus 20'/count of conduit + wire if I am looping up and down. I add this to the horizontal length from the rotometer. I color all of this conduit one color so I can see what I took off as 1/2" EMT with 2#12s.
5. Same process for 1/2" with 3#12s, then 4#14s, and all other combinations. I color each combination with a different color.
Boxes, rings, covers, devices, wirenuts, fasteners etc. all derive from the lighting and device counts. Straps, fasteners and couplings and wire come from conduit footages. (sort of a modified assembly take-off method)
I take all of the branch off for the job using something like this method, with variations for different wiring methods.
For feeders, I have feeder take-off sheets that I do by panel by circuit. That way, I don't miss any feeders. It is a "from" "to" system. I start at the transformer and go to the last panel, coloring off stuff as I go.
It's hard to describe, but easy to do with practice. Pretty accurate, but not real fast. Not that slow, though, if you learn good habits and practice.
I haven't taken any estimating classes in a long time, so there are probably better methods and ideas around now.
I'm sure that using estimating software with direct input measuring devices will be much faster. But even when I add this stuff, my general take-off procedure will remain the same until someone shows me a procedure/sequence that works better.
When I completely finished, if I do the project, then I give the color coded drawings and various take-off sheets to my job electrical superintendent.
If he has better ideas, then we change the take-off accordingly. When we agree and everything is double-checked, then the materials are ordered -- they match the drawing layout.
We don't really end up making many field changes after he is on-site, since we are pretty thorough in the planning stage. We look at all of the drawings -- architectural, structural, mechanical, details, etc. I'm big on preplanning -- you catch a lot of mistakes and conflicts before they happen.
He takes this info to the jobsite with him and has it to refer to during construction. He pretty much puts it in according to our plan. That way, all of the materials needed work out, and hardly anything is missing. Everything fits, with very little left over, and very few trips to the supply house.
This probably seems slow and tedious, and it probably is. But I hardly ever run over on materials or labor -- I almost always stay within estimated cost.
Re: Estimating BCW
tx2step
I appreciate the response. It definitely sounds like you have a more thorough approach which is kind of what I need. Could you possible send me copies of your blank feeder take off sheets and any other "take off" sheets that you use? E-mail darrins18@yahoo.com
As far as software, I have tried using some software that is out there. They all have a pretty substantial data base which is nice. But the thing I hate is most of them you cannot "Categorize" anything for future reference. For example, if I am taking off for a main panel, let?s say Panel LP-1, and then I like to have a heading or category if you will titled "Panel LP-1 Feeder" or something to that effect. That way I can keep tracked of what I have finished in my estimate especially if I get distracted i.e. phone calls, lunch etc. More importantly, if I get the job, which might be weeks later before I find out, when I pull the estimate file for that job, I can look and see with ease what I figured and how with ease. I will have other categories such as ?Main Floor Receptacle BCW? etc. Most of the software "Compiles" the conduit, wire, fitting etc into one lump sum for the summary and does not tell me what I used for what and how many.
Right now, after I do my take offs, I use an excel spread sheet that has Macros scripts programmed into it. When I am ready to put in my estimate and quantities, I launch Macros that merges other spread sheets with the main spreads that has labor and cost for items such as conduit, boxes, wire and fittings.
I still use an electronic rotometer like you do to get lengths. Although, I do not use a counter, I use a red pencil. The reason is so I can keep tracked of what I have counted. As I go across the print, everything that gets counted gets crossed off with a red pencil then I write them down on a piece of notebook paper. That way if I get distracted or loose concentration, I can see what I have counted immediately with the red pencil marks instead of starting all over. I usually do a section at a time such as a corner or wing of a building so that my quantities do get to big at one time. Then when I write them down on a piece paper, I will just add up all my sub quantities.
tx2step
I appreciate the response. It definitely sounds like you have a more thorough approach which is kind of what I need. Could you possible send me copies of your blank feeder take off sheets and any other "take off" sheets that you use? E-mail darrins18@yahoo.com
As far as software, I have tried using some software that is out there. They all have a pretty substantial data base which is nice. But the thing I hate is most of them you cannot "Categorize" anything for future reference. For example, if I am taking off for a main panel, let?s say Panel LP-1, and then I like to have a heading or category if you will titled "Panel LP-1 Feeder" or something to that effect. That way I can keep tracked of what I have finished in my estimate especially if I get distracted i.e. phone calls, lunch etc. More importantly, if I get the job, which might be weeks later before I find out, when I pull the estimate file for that job, I can look and see with ease what I figured and how with ease. I will have other categories such as ?Main Floor Receptacle BCW? etc. Most of the software "Compiles" the conduit, wire, fitting etc into one lump sum for the summary and does not tell me what I used for what and how many.
Right now, after I do my take offs, I use an excel spread sheet that has Macros scripts programmed into it. When I am ready to put in my estimate and quantities, I launch Macros that merges other spread sheets with the main spreads that has labor and cost for items such as conduit, boxes, wire and fittings.
I still use an electronic rotometer like you do to get lengths. Although, I do not use a counter, I use a red pencil. The reason is so I can keep tracked of what I have counted. As I go across the print, everything that gets counted gets crossed off with a red pencil then I write them down on a piece of notebook paper. That way if I get distracted or loose concentration, I can see what I have counted immediately with the red pencil marks instead of starting all over. I usually do a section at a time such as a corner or wing of a building so that my quantities do get to big at one time. Then when I write them down on a piece paper, I will just add up all my sub quantities.
tx2step
Senior Member
- Location
- North Texas, DFW area
Re: Estimating BCW
Darrin --
All of my takeoff sheets are hard copies. I don't have one in an electronic format that I can email to you. Let me think about that.
The takeoff sheet that I use the most is just a simple grid. Columns and rows, landscape orientation, with the far left column being about 1.25" wide. The top 2 rows are set off by a heavier line that separates it from the next (3rd) row. I use those top rows to label what each column represents. every 5th row is set off by a heavier line, just to keep it easier to stay on the correct row.
I use it for feeders, too, more often than a feeder sheet. For instance, in the wide column of the first working row, I might put "Xfmr to MDP" "4 X 80'". That would tell me that the entrance is 4 parallel conduits 80' long horizontally.
The first column I would label 24" X 48" Trench and insert a length of 80'.
Next column label, 4" PVC Sch 40 and insert a quantity of 340' (80' + 2 X 2.5' rise on each end = 85', 85' X 4 ea = 340')
Next column label, 4" PVC 90 elbow, quantity 8.
Next column label, 4" coupling, quan 12 (one end of the conduits will have a coupling already).
Next Column label, 4" Male adapter w/ LN, quan 4.
Next Col. label, 4" Bells, quan. 4.
I just continue on until I have everything listed for this entrance, wire and everything. If I run out of columns, then I'll drop down a couple of darker horizontal lines (about 10 lines) and use the two rows above for column headers and label the first row "Xfmr to MDP" and just keep on going until I have everything listed it will take. Usually, I'll dedicate one takeoff page to the entrance if the materials and wiring method is different from the feeders (underground vs. overhead, for instance).
I keep a separate pricing page of Misc. things that I see will be needed that I don't want to put on one of these pages -- such as a transformer pad, panel housekeeping pad, etc.
I'll use the same technique for the panel feeders, usually starting a 2nd takeoff sheet for them. The first row might say "MDP to P1, 2 X 180')", the next row might say MDP to P2, 1 X 240'. When I'm done with all of the feeders, I total all of the columns to see how much 4" EMT, etc. is taken off on that page.
When I transfer each of the quantities to a pricing page or to a material consolidation sheet, I circle each column total so I know I have included it and not missed anything.
Usually 6 or 8 pages will cover the feeder system for a medium size commercial project.
For branch wiring, I do something similar, without doing any "from to" thing. As a minimum, I separate out (list) the quantities that I take off for each electrical drawing. I may also list various systems separately.
When I'm done, I can give these pages to my superintendent and he can tell how I took the job off and where my quantities came from. Aided also by the color coding that I do on the drawings as I take stuff off. It gives anyone a pretty complete track of how I got my bill-of-material.
There is estimating software available that will do what I call "segment estimates". It's like a whole bunch of separate small estimates that will add up to the entire project. You can take off the feeders (identified as such), then the branch separately. Enter the complete bill-of-material (separately) for each of the lighting drawings, or power drawings, or however it makes sense to segment (divide up) the estimate. The software will keep all of the segments separated. When you are finished, you run a consolidated estimate that adds and consolidates everything into your overall estimate. But all of the segments remain discrete and available. You can print out all of the materials and/or a labor estimate (and a completely priced cost estimate if you want it) for any of the individual segments. There are some very significant advantages and uses for this type of estimate.
You can hand a foreman a bill of material for the 3rd floor lighting system, so he can make sure everything needed is there when he starts. You can tell the superintendent how many manhours are in your estimate for installing that particular segment of the work.
It makes it far easier to monitor and analyze progress and productivity.
It all starts with a logically segmented estimate. It also makes it easier to spot mistakes, too. Does one segment or quantity look too low or is stuff obviously missing?
Get a click-counter if you don't already have an equivalent. When you are counting and marking stuff, you mark and click at the same time. If you get distracted, you don't have to remember your count -- it's on your hand held clicker. You just resume counting & marking where you left off.
What electronic rotometer do you use? How do you like it?
Have you read any of the various estimating books that are out there? I haven't read any in quite a while. I'm sure there are some great ones out there. I'd like to read any that you think are good. I know Mike Holt has one available, but I haven't read it yet.
Go to estimating classes and seminars when they are available. You'll pick up ideas at all of them.
This is all difficult to describe. Hopefully it makes sense. If anything isn't clear, just ask.
Darrin --
All of my takeoff sheets are hard copies. I don't have one in an electronic format that I can email to you. Let me think about that.
The takeoff sheet that I use the most is just a simple grid. Columns and rows, landscape orientation, with the far left column being about 1.25" wide. The top 2 rows are set off by a heavier line that separates it from the next (3rd) row. I use those top rows to label what each column represents. every 5th row is set off by a heavier line, just to keep it easier to stay on the correct row.
I use it for feeders, too, more often than a feeder sheet. For instance, in the wide column of the first working row, I might put "Xfmr to MDP" "4 X 80'". That would tell me that the entrance is 4 parallel conduits 80' long horizontally.
The first column I would label 24" X 48" Trench and insert a length of 80'.
Next column label, 4" PVC Sch 40 and insert a quantity of 340' (80' + 2 X 2.5' rise on each end = 85', 85' X 4 ea = 340')
Next column label, 4" PVC 90 elbow, quantity 8.
Next column label, 4" coupling, quan 12 (one end of the conduits will have a coupling already).
Next Column label, 4" Male adapter w/ LN, quan 4.
Next Col. label, 4" Bells, quan. 4.
I just continue on until I have everything listed for this entrance, wire and everything. If I run out of columns, then I'll drop down a couple of darker horizontal lines (about 10 lines) and use the two rows above for column headers and label the first row "Xfmr to MDP" and just keep on going until I have everything listed it will take. Usually, I'll dedicate one takeoff page to the entrance if the materials and wiring method is different from the feeders (underground vs. overhead, for instance).
I keep a separate pricing page of Misc. things that I see will be needed that I don't want to put on one of these pages -- such as a transformer pad, panel housekeeping pad, etc.
I'll use the same technique for the panel feeders, usually starting a 2nd takeoff sheet for them. The first row might say "MDP to P1, 2 X 180')", the next row might say MDP to P2, 1 X 240'. When I'm done with all of the feeders, I total all of the columns to see how much 4" EMT, etc. is taken off on that page.
When I transfer each of the quantities to a pricing page or to a material consolidation sheet, I circle each column total so I know I have included it and not missed anything.
Usually 6 or 8 pages will cover the feeder system for a medium size commercial project.
For branch wiring, I do something similar, without doing any "from to" thing. As a minimum, I separate out (list) the quantities that I take off for each electrical drawing. I may also list various systems separately.
When I'm done, I can give these pages to my superintendent and he can tell how I took the job off and where my quantities came from. Aided also by the color coding that I do on the drawings as I take stuff off. It gives anyone a pretty complete track of how I got my bill-of-material.
There is estimating software available that will do what I call "segment estimates". It's like a whole bunch of separate small estimates that will add up to the entire project. You can take off the feeders (identified as such), then the branch separately. Enter the complete bill-of-material (separately) for each of the lighting drawings, or power drawings, or however it makes sense to segment (divide up) the estimate. The software will keep all of the segments separated. When you are finished, you run a consolidated estimate that adds and consolidates everything into your overall estimate. But all of the segments remain discrete and available. You can print out all of the materials and/or a labor estimate (and a completely priced cost estimate if you want it) for any of the individual segments. There are some very significant advantages and uses for this type of estimate.
You can hand a foreman a bill of material for the 3rd floor lighting system, so he can make sure everything needed is there when he starts. You can tell the superintendent how many manhours are in your estimate for installing that particular segment of the work.
It makes it far easier to monitor and analyze progress and productivity.
It all starts with a logically segmented estimate. It also makes it easier to spot mistakes, too. Does one segment or quantity look too low or is stuff obviously missing?
Get a click-counter if you don't already have an equivalent. When you are counting and marking stuff, you mark and click at the same time. If you get distracted, you don't have to remember your count -- it's on your hand held clicker. You just resume counting & marking where you left off.
What electronic rotometer do you use? How do you like it?
Have you read any of the various estimating books that are out there? I haven't read any in quite a while. I'm sure there are some great ones out there. I'd like to read any that you think are good. I know Mike Holt has one available, but I haven't read it yet.
Go to estimating classes and seminars when they are available. You'll pick up ideas at all of them.
This is all difficult to describe. Hopefully it makes sense. If anything isn't clear, just ask.
Re: Estimating BCW
You can make a custom graph paper right on your computer:
http://mathematicshelpcentral.com/graph_paper.htm
Actual program here ~ completely free..no fee..no spyware/adware. Graph Paper Printer Program
Version 4.21
I use this all the time:
- when at a customer's house, I can sketch the area (great for landscape lighting, kitchen/bath remodels)
- back at the office for various take-offs (completely scalable/customize)
- when the wife decided it's time to "rearrange a room ~ it's easier to move little paper squares than armoires and china cabinets.
Did I mention it was free?
[EDIT: continuing the tangent to nowhere]
[ June 23, 2005, 08:45 PM: Message edited by: celtic ]
You can make a custom graph paper right on your computer:
http://mathematicshelpcentral.com/graph_paper.htm
Actual program here ~ completely free..no fee..no spyware/adware. Graph Paper Printer Program
Version 4.21
I use this all the time:
- when at a customer's house, I can sketch the area (great for landscape lighting, kitchen/bath remodels)
- back at the office for various take-offs (completely scalable/customize)
- when the wife decided it's time to "rearrange a room ~ it's easier to move little paper squares than armoires and china cabinets.
Did I mention it was free?
[EDIT: continuing the tangent to nowhere]
[ June 23, 2005, 08:45 PM: Message edited by: celtic ]
tx2step
Senior Member
- Location
- North Texas, DFW area
Re: Estimating BCW
No... I hold the click counter in my left hand and a colored pencil in my right hand.
When I count stuff, I color it off with my right hand and click the counter with my left. I don't try to keep a count in my head. This process becomes automatic.
I can think about other stuff that I see on the plans as I do this because I'm not trying to keep a count in my head.
I just use a standard mechanical click counter that you can get at any office supply for around $10. It fits in the palm of your hand -- about the size of a ping-pong ball with a ring that goes over one finger, and you press a lever/button with your thumb. It has a reset knob on the side. I like this variety over other styles because you get an audible click, and it's very hard to press accidentally or to reset accidentally. Counting mistakes are rare.
I've seen estimating software probes that had colored lead in them -- they counter one count every time you pressed the lead against the paper. You had to be careful using it, though. It was fairly easy to double count something.
[ June 24, 2005, 01:15 PM: Message edited by: tx2step ]
No... I hold the click counter in my left hand and a colored pencil in my right hand.
When I count stuff, I color it off with my right hand and click the counter with my left. I don't try to keep a count in my head. This process becomes automatic.
I can think about other stuff that I see on the plans as I do this because I'm not trying to keep a count in my head.
I just use a standard mechanical click counter that you can get at any office supply for around $10. It fits in the palm of your hand -- about the size of a ping-pong ball with a ring that goes over one finger, and you press a lever/button with your thumb. It has a reset knob on the side. I like this variety over other styles because you get an audible click, and it's very hard to press accidentally or to reset accidentally. Counting mistakes are rare.
I've seen estimating software probes that had colored lead in them -- they counter one count every time you pressed the lead against the paper. You had to be careful using it, though. It was fairly easy to double count something.
[ June 24, 2005, 01:15 PM: Message edited by: tx2step ]
tx2step
Senior Member
- Location
- North Texas, DFW area
Re: Estimating BCW
Hmmm... Looks like it may finally be time to retire my old mechanical rotometers.
Do you use the "Classic" model or the "Scale Master II"?
How accurate is it?
How durable is it?
If you use the "II", do you have the computer interface? How does that work?
[ June 24, 2005, 01:45 PM: Message edited by: tx2step ]
Hmmm... Looks like it may finally be time to retire my old mechanical rotometers.
Do you use the "Classic" model or the "Scale Master II"?
How accurate is it?
How durable is it?
If you use the "II", do you have the computer interface? How does that work?
[ June 24, 2005, 01:45 PM: Message edited by: tx2step ]
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