Residential Calculations
Residential Calculations
(OP)
I do a lot of residential projects and find myself approaching the calculations differently for nearly every job. For small jobs, not usually a big deal, but for the bigger ones it turns into a challenge.
I start off a bigger project thinking okay, I'm going to be organized this time and label everything neatly so that I can track loads, design posts, etc. But it's 2 days later and I am saving calcs as "Back left header kitchen long window". 40 members later and it's a mish-mosh of beams and joists and rafters that become a nightmare when I have to go back and change something.
So I'm starting a big brand new house next week and wanted to get some ideas how people normally approach these types of large projects. Hoping I can make my own system to save as much time on these PITA jobs as possible. Appreciate it.
I start off a bigger project thinking okay, I'm going to be organized this time and label everything neatly so that I can track loads, design posts, etc. But it's 2 days later and I am saving calcs as "Back left header kitchen long window". 40 members later and it's a mish-mosh of beams and joists and rafters that become a nightmare when I have to go back and change something.
So I'm starting a big brand new house next week and wanted to get some ideas how people normally approach these types of large projects. Hoping I can make my own system to save as much time on these PITA jobs as possible. Appreciate it.
RE: Residential Calculations
https://res.cloudinary.com/engineering-com/raw/upload/v1684560661/tips/Simple_Span_Beam_Design_fca7tu.xlsm
a more recent version...
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So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates
-Dik
RE: Residential Calculations
I have a 'house design procedure' I worked up. I'll type it up and share it next time I'm at my computer. But like dik said, for beams and headers and such labeling them as B-X, H-X, C-X and so on is a good convention.
RE: Residential Calculations
When I first start designing a floor, I'll usually come up with a preliminary framing layout with beam and column labels as noted above, and I'll make the labels red in cad. After each member has been design, I'll change the label to white or green.
RE: Residential Calculations
RE: Residential Calculations
I've been trying to get out of doing the drafting myself (it's about 3/4 of the time, and I can hire it out for about 1/8th of the fee...), so I may not adopt that one for myself, but something to keep in mind...
RE: Residential Calculations
Determine Loading
Preliminary Lateral Analysis:
Preliminary Gravity Analysis:
Design Secondary (Joist/Rafter) Framing
Design Shear Walls and Diaphragms (need dead load reactions from secondary framing)
Design Primary Framing (need secondary framing reactions and shear wall chord reactions)
Design Foundations
Sketch sections and project specific detailing/connections
Write notes and/or specifications
Finalize drawings.
RE: Residential Calculations
RE: Residential Calculations
I have a 4 month backlog of fees set on my terms, no negotiating.
RE: Residential Calculations
We have a pretty slick spreadsheet that has links for everything. The first few tabs set up the loads from snow, live, seismic, and wind, and allow you to select those different load sets through the rest of the spreadsheet. The spreadsheet itself handles 5 stories of shear walls with 15 different lateral lines and multiple options per line, 150 beams (simply supported with either or both ends cantilevered or multi-spanning with uniform loads), 20 checks for studs, 50 checks for foundation walls (simply supported), 30 checks for rafters/joists, and a check for a simple diaphragm. All points loads from beams can be "called" later in the spreadsheet, either applying to other beams or to the foundations. All of these calcs are linked to schedules in excel corresponding to the marks called out on the plan. The schedules can either be copied and pasted directly on a pdf or entered in as a data link into AutoCAD, which can automatically update. We have a word doc that has links to all those different calcs and by simply opening the word doc those reports filter and update. Our details are also auto populated in the spreadsheet depending on what beams/joists/shear walls you put in, and those details auto-filter at the end of the spreadsheet, and our AutoCAD tools will then bring in those details to our DWG.
Through all this automation we've found that even small $300 garages can be profitable because of the significant automation behind the scenes. This has taken YEARS for the company to develop and it was mostly accomplished through cheap yet innovative students. Residential work can be super profitable if you have automation for all those routine tasks. This also allows our time to be spent on the engineering aspects of the project rather than the reports.
RE: Residential Calculations
This.
YoungGunner...I'm not in Utah and will never compete with you...what would it take to get a copy? (I'm kidding....unless you're willing to share)
I have one in the works - the goal is to be able to enter some basic parameters and have it automate the lateral analysis. I haven't figured out the best way to automate gravity calcs, though. I've tried software packages, etc., but none of them work as well as I'd like.
RE: Residential Calculations
There was an hours work in producing a complete set of drawings, including standard notes, maybe more if I had to drive out to the country to look after a soil 'test pit' excavation. The standard drawings even had the soil profile included... Fees for these drawings were in the order of $1000, and it was easy to make money with them. For a simple house, there were three drawings to the set... there was even a drawing list included. About the only thing that changed was the Project Title.
-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates
-Dik
RE: Residential Calculations
Unfortunately it is a very proprietary spreadsheet. That is impressive you have one in the works to complete lateral analysis. While we have a lot of automation, on small jobs we are simply reduced to taking a plethora of measurements and entering them into our analysis, which will autosize most every member. Complicated structures still require a lot of thought and engineering judgement.
RE: Residential Calculations
So I cheated a bit on mine for lateral. Since I'm in hurricane country with no real seismic activity (you can feel one distant quake every few generations), it's all wind. And the WFCM has these handy guides for simple houses, like this one: 115mph Exposure C
So I validated a couple of them, then entered a bunch of their results into a spreadsheet, used some interpolation to fill in between, and then did some validation on those results. The results were acceptable to me (within a few %), so now I use that to determine MWFRS loading at each level. It's a whole lot easier than trying to do a detailed directional or even envelope calculation in the background.
There's still plenty of manual alignment and summing of forces, but it's coming along...slowly.
RE: Residential Calculations
$300 and Garage should never be used in the same sentence!
RE: Residential Calculations
RE: Residential Calculations
Then, my spreadsheets are setup so each member has one line in excel. There's a beam table, footing table, column table, and wall bracing table, and each member gets a new row in the corresponding table.
RE: Residential Calculations
RE: Residential Calculations
It seems odd to me that they didn't start with wood. After all, when I'm doing a steel framed building I'm in RISA - using Enercalc for anything more than assisting with wind analysis or something doesn't even cross my mind. But smaller projects and wood buildings...that's the ideal use for Enercalc for me. But perhaps I don't 'fit the mold'.
RE: Residential Calculations
RE: Residential Calculations
RE: Residential Calculations
RE: Residential Calculations
RE: Residential Calculations
RE: Residential Calculations
In terms of project fees, I always try to charge what the market will bear, unless that would result in a fee so low that the project isn't worth the liability, in which case I would avoid that project. If I get every project I give a price on, then I figure I'm not charging enough for the work. As a general policy, I usually won't stamp anything for less than $1,000. Now, if I'm actually able to improve my workflow to the point that I'm twice as efficient, I'm not going to charge less for a given project. If anything, I might charge more considering that I can now get the project done more quickly, which is presumably a greater value to the client. I would never do a garage for $300, unless I was starving. That's just insane.
RE: Residential Calculations
RE: Residential Calculations
The homeowner goes "$550?! That's like the cost of a home inspection! I thought you were going to say something like $70." I said uh yeah I know how much home inspections cost, but I'm a licensed engineer, that's quite the step up. I told him you're lucky I said $550 because most people aren't going to answer the phone for less than $1k.
I didn't care about the guy complaining about the price, but the funniest part was $70. Who even comes up with that number? That's like 3 things at a grocery store these days. I'm not sure $70 even covers gas and the tolls.
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But anyway, back to my OP, I love my spreadsheets, but 95% of my beam designs for residential are in Forte. Very easy to use, can link loads, change things quickly. It's free too. I couldn't imagine having giant spreadsheets like described above. I cannot imagine the amount of time spent for some of those. I want as many things done on computer programs as possible. I just want to refine my labeling and numbering system to speed up the design and drafting processes.
RE: Residential Calculations
RE: Residential Calculations
I do like the no plot layer suggestions. When I worked for a real office doing a keyplan was no problem, but since it's just me now, saving time and incorporating the keyplan into CAD would save me a lot of time. Time is money.
RE: Residential Calculations
Maybe I should up my game.
RE: Residential Calculations
I just opened Forte for the first time and made an account. I cant believe that it's free! Most residential really doesn't even need paid calc software it looks like. Thank you so much for this.
RE: Residential Calculations
RE: Residential Calculations
I'd say most report and site visit jobs are $700-900 depending on how long the report will be.
It's summertime now so driving times around here will be twice as bad starting this weekend so I might tack on $50 to every job haha.
RE: Residential Calculations
RE: Residential Calculations
You can't worry about these types of clowns though. For me, I can afford to charge on the lower end of the ranges because I have no overhead besides insurance, but that doesn't mean I'm going to sell myself short. People need to pay not only for our time but also our experience.
RE: Residential Calculations
I won't ever do a complete "structural inspection". For a $375 site visit, I will look at a few issues that were raised in a pre-purchase home inspection report or look at a concern a homeowner has or an issue a contractor needs fixing. Maybe time to charge more?!
Funny, most people are happy with my fees but I get the occasional, "you were here only 15 minutes and you want me to pay you what?"
RE: Residential Calculations
Same here. I work out of my guest bedroom. Don't have any subscription software except Office. I'm not a member of any organization.
I keep it pretty lean. But, yeah, i'm gonna up my rates.
RE: Residential Calculations
Really? I am paying for google for a basic website and google drive. AutoCAD LT. Office. Adobe acrobat pro. Quickbook.
RE: Residential Calculations
Having the latest and greatest is generally more convenient and can help automate some tasks, but if you built your business around manual methods and you're comfortable with them, you don't need a bunch of subscriptions.
RE: Residential Calculations
RE: Residential Calculations
Oh, I forgot, I do pay my Acct. every month to use Quickbooks online. Also a few dollars for Google storage.
My overhead with insurance ends up being less than 20k per year.
RE: Residential Calculations
I already paid for 2TB of Google Drive storage so I just use that for saving everything. Google sheets for my record keeping and financing. Foxit free version for PDFs. Had a previous version of AutoCad and Office on my computer already. Forte is also free of course. Want to switch over to quickbooks soon, but who has the time.
Insurance is obviously the big one for us structural engineers, so keeping the rest of the costs down is important. For me I'm busy just doing what I'm doing so I don't need to go crazy and get an office and a wide format printer or anything like that right now.