Small Project Design

This message has been cross posted to the following Discussion Forums: Small Project Practitioners and Custom Residential Architects Network .
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I am the owner of a small residential design firm.  While I have over a decade of experience in my field, I am new to owning my own firm.  I lack confidence in my structural skills, so I developed a relationship with a structural engineer to assist me in developing my framing plans, and to size the structural members.  Its been a great relationship, but now that my projects are starting the construction phase, I am getting a lot of push back from contractors that the structures are over-designed. While I trust my engineer's calculations, I am also realistic that the contractor has built way more house than I have at this point, and has a better understanding for building standards.  Has anyone else dealt with a similar situation?  Any advice on how to determine when the contractor is right vs. insisting he follow the engineered designs?  Any books or other resources you might recommend?  Or any other business models out there that might give me the structural support (no pun intended) that I am looking for while accounting for standard business practices?

Thank you,
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Lisa Cohen AIA
Architect
LMC Architecture, LLC
Fair Lawn NJ
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1.  The engineer is providing drawings that he has prepared using a factor of safety. This is prudent.
2.  The contractors know how they have constructed due to 20 years of experience.  Maybe they have been doing it wrong for 20 years.
3.  I would guess that the contractor's work, his rule of thumb, does not include the factor of safety that the engineer uses.
4.  The contractor also does not always understand all the conditions that is the standard for a well engineered project.
5.  There are always other ways to construct a project.  Contractors tend to know the less expensive way, not necessarily the right way.

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John Feick AIA
Feick Design Group, Inc.
Sandusky OH
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Codes have changed and not all contractors (and architects) are familiar with the changes, some of which seem esoteric to those of use who have been around awhile.  Structural engineers are often versed in codes and standards that aren't the ones we tend to focus on as architects.  For instance, due to changes in the BIA ASTM deflection standards, it is now virtually impossible to build a residential brick veneer structure with 2 x 4 construction (not withstanding insulation requirements) even though that sort of construction was done all the time years ago.

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Jeffery Clarke AIA
T. Jeffery Clarke Architect LLC
Princeton NJ
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Original Message:
Sent: 09-25-2014 17:34
From: John Feick
Subject: Working with Structural Engineers

1.  The engineer is providing drawings that he has prepared using a factor of safety. This is prudent.
2.  The contractors know how they have constructed due to 20 years of experience.  Maybe they have been doing it wrong for 20 years.
3.  I would guess that the contractor's work, his rule of thumb, does not include the factor of safety that the engineer uses.
4.  The contractor also does not always understand all the conditions that is the standard for a well engineered project.
5.  There are always other ways to construct a project.  Contractors tend to know the less expensive way, not necessarily the right way.

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John Feick AIA
Feick Design Group, Inc.
Sandusky OH
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I would tell you it's part of a learning curve, the structural engineer will typically over engineer everything but I wouldn't be afraid to question them or let them know you are getting push back from your clients (they are their clients too).  There is now free software from large companies like Weyerhaeuser and Boise Cascade that will allow you to calculate nearly any part of a wooden structure, it would at least allow you to go back to the Engineer with solid data for a discussion.  I use the "Forte" software from Weyerhaeuser, I picked it up in about 30 minutes, it is very user friendly but it doesn't calculate steel.  I use a program called "Beamcheck" if I need a steel beam which is a purchased program but there may be some software that's free. 

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Christopher Walsh AIA
Tandem Architecture
Buffalo Grove IL
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Don't be bullied by the Contractor.  Tell him to provide his own structural analysis, at his expense, if he disagrees.  Simultaneously, go back to your structural engineer and ask him to defend his decisions and share with you his loading calculations.  Do your research to reinforce your decisions.  There might be additional wind load requirements put in place post Hurricane Sandy that effect structural design.  Codes change over time, standard business practices sometimes need to change to keep up.

Good luck.

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Philip Mitropoulos AIA
Firm Owner/Architect
Mitropoulos Architects
Douglaston NY
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Lisa,

Just because how the contractor built it in the past got past the inspector does not mean it meets current code.  There have been just a few updates over the years. 

I'd start by sharing the general contractors' comments with the structural engineer.  It might be worthwhile to meet with all parties for a quick discussion of the whys and wherefores of the structural design.

And it would be worthwhile to talk with the structural engineer about the "overdesign" issue.  I recall one engineer who always used 3/4" bolts to connect wood beams.  I think the beams grew by one size just to make up for all the holes.  It is good to be sympathetic to the contractors - they do have some experience, and some may start "spreading the word that "Lisa and her structural engineer overdesign everything, Mr./Mrs. Homeowner, and I know another architect who doesn't ..."

That said, if these are "bid" projects -- why is the contractor not just building what the drawings show, and what the permit calls for?  Almost makes one wonder if you should do framing inspections to see what they left out.

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Joel Niemi AIA
Principal
Snohomish WA
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I had my own practice for 12 years, and did all of my own structural calculations for my residential projects. I too would get push back fro contractors.  Most of the time, I had purposely "over designed" a structural member because the deflection criteria on floor loads of L/360 allowed by the code, created springy floors on long spans.  Once I explained this to contractors and owners, the pushback generally stopped. Contractors are use to building to the bare minimum of code criteria.  Also check to see what type of live load and dead loads your engineer is using, and if he is applying any live load reduction criteria. I know there are several computer programs that can help you with sizing members, but it is up to you to determine the associated loads and load path on your structure. Most of the time, I only had to use a simple span with uniform load to size members.

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Jeffrey Bumb AIA
Fox Architects
Ballwin MO
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Lisa,

I have a similar practice and have been coming across this for years, especially when my practice (and me) was young.  Here's a few words of advice and I'm sure you'll get more from others.
1.  Make sure you choose consultants that are experienced in your type of work.  A structural engineer with residential experience (wood frame construction, etc.) is preferable to someone who typically does office buildings.  Don't be afraid to challenge the engineer if the structure seems excessive but keep in mind they should be, at a minimum, designing the structure to code and often should design above and beyond code for a proper job.  L/480 is way better than code minimum L/360, for example, but sometimes still not good enough. 
2.  If the contractor is suggesting changes, for whatever reason, then ask him to provide a list of suggestions for the engineer to review and approve/disapprove.  I've learned that contractors often have good suggestions that lead to cost savings (not as much) or ease of construction (usually) but have them checked first if you're not comfortable making the call yourself.  Not all suggestions are good, no matter how experienced the contractor.  Create a paper trail!  Remember it's your stamp and liability on the line,
3.  Most contractors are great people and willing to work with the Architect for the benefit of the Owner or Contractor/Architect relationship and they bring another valuable perspective to the work but once in a while you come across a contractor who tries to establish himself as the "boss" once construction starts and will try to drive a wedge between Architect and Owner.  If the Contractor is adamant and wants to implement his suggestions without your approval then you should advise the Owner in writing and shift responsibility for any future problems to the Contractor.  

I'm sure you'll get other great suggestions.  Good Luck.

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Angelo Biondi AIA
Owner
A.Biondi Architects
Highland Park IL
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I recommend you invest in StruCalc software (www.strucalc.com ) with which you can easily do basic structural design calculations.  I use it for my own residential preliminary design work - ie sizing joists, rafters, beams and even footings.  You could use it to double-check your engineer's designs as well. It's not that expensive, pretty easy to use, and quite comprehensive. My structural consulting engineer actually uses this program for his final design work, but don't let that scare you - as I say - it's reasonably easy to use for your purposes.
Good luck !

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Robert Larsen AIA
Principal
Robert R. Larsen, A.I.A.
Denver CO
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Dear Ms. Cohen, There has been a lot of useful advice posted. I ran a design/ build firm for many years. I feel fortunate to have seen both sides of this discussion. I recommend that you do as much as possible to become familiar with the basics of your building type. One of the other respondents mentioned the nuance of wood frame construction. It is based on science, but as one of my mentors told me it is an inexact science. Your structural consult needs to be well versed in the construction type. It is helpful to be able to at least check the primary structural numbers yourself. This tends to make it easier to sort out both good advice from a competent builder as well as reasonable modeling from your structural consultant. It also greatly aids in the design process when what "if"ing things. We have found StruCalc one of a number of useful tools to quickly look at base load information. ---------------------------- William Thompson, AIA, LEED AP BD+C Principal Wm. Thompson AIA & Assoc., Architect Guilford, CT -------------------------------------------
Original Message: Sent: 09-25-2014 18:33 From: Robert Larsen Subject: Working with Structural Engineers I recommend you invest in StruCalc software (www.strucalc.com <http://www.strucalc.com> ) with which you can easily do basic structural design calculations. I use it for my own residential preliminary design work - ie sizing joists, rafters, beams and even footings. You could use it to double-check your engineer's designs as well. It's not that expensive, pretty easy to use, and quite comprehensive. My structural consulting engineer actually uses this program for his final design work, but don't let that scare you - as I say - it's reasonably easy to use for your purposes. Good luck ! ------------------------------------------- Robert Larsen AIA Principal Robert R. Larsen, A.I.A. Denver CO -------------------------------------------
Original Message: Sent: 09-24-2014 10:04 From: Lisa Cohen Subject: Working with Structural Engineers This message has been cross posted to the following Discussion Forums: Small Project Practitioners and Custom Residential Architects Network . ------------------------------------------- I am the owner of a small residential design firm. While I have over a decade of experience in my field, I am new to owning my own firm. I lack confidence in my structural skills, so I developed a relationship with a structural engineer to assist me in developing my framing plans, and to size the structural members. Its been a great relationship, but now that my projects are starting the construction phase, I am getting a lot of push back from contractors that the structures are over-designed. While I trust my engineer's calculations, I am also realistic that the contractor has built way more house than I have at this point, and has a better understanding for building standards. Has anyone else dealt with a similar situation? Any advice on how to determine when the contractor is right vs. insisting he follow the engineered designs? Any books or other resources you might recommend? Or any other business models out there that might give me the structural support (no pun intended) that I am looking for while accounting for standard business practices? Thank you, ------------------------------------------- Lisa Cohen AIA Architect LMC Architecture, LLC Fair Lawn NJ -------------------------------------------

My first thought is, contractors always push.  Don't be bullied.  Don't let him/her get you second guessing your drawings. 
Ask your contractor what he/she is suggesting and let him/her know you will pass their concerns on to the engineer. 
Build a relationship with your engineer.  Especially If you plan to use him/her on all of your projects.  You need to trust their work. Let him/her know that you want a safe building, but not an overly expensive one.  Let him/her know that you want to work as a team, and if they sees ways you could make minor changes in your design and save your client money, you want to hear their thoughts.
It takes many people to build a building, so build relationships.
If you are not confident and able to make decisions, construction will definitely test you.  Unless they are pouring concrete, a few hours to get the knowledge to make a right decision won't hurt anything.  Just tell your contractor when you will get back to them with the answer, so you don't leave them hanging.  If you don't have an answer by the time you said you would call, call them and let them know.  This builds trust.
Build a team you trust, and ask questions. It's also OK to brainstorm with your team.  When it comes to the structure, listen to others, but lean on your engineer for decisions pertaining to the structure.  
A few homes under your belt and you'll be soaring through projects.  For now, put one foot in front of the other, build your team, and build trust.
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Rachelle Freegard AIA
Architect
Bailey Edward Architecture
Champaign IL
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Ms. cohen:  Trust in your Structural Engineer.  Many homebuilders do not understand the reasons for the structural details.  Many times the builders have never worked with an Architect much less a Struct. Engineer.  If you can afford another hour of his time ask him to look at the question again.  Many times it involves wind, snow loading, and uplift.  These are concepts not taught in the builders' schooling.  

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Nelson B. Nave AIA
Owner
Nelson Breech Nave, AIA Architect
Kalamazoo MI
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Lisa
The best way to learn about framing a structure of the size and type you are designing is to spend time in the field observing, or better yet to have spent time doing the framing yourself as part of a construction crew. I think multiple job site visits to observe construction methods (even on projects that are not yours) and structural systems being installed, if not actually performing some of the work yourself, in the field should be a basic requirement of any architect that wants a good grasp of how a building is built, and how each system relates to the end product. Stop by any number of construction projects you pass by and ask to check out what is going on. After a while your field knowledge will be expanded greatly. Don't be afraid to ask questions, even if they sound dumb, you will surely learn something from even the grumpiest old field supervisor. Not to be sexist, but construction workers, and even plan checkers, will always give a smiling female who asks for help more time than they will to a balding middle age man.

I don't mean to put down on your education or question your competence, it is just that visiting job sites from a young age, and framing several residential buildings myself from the ground up, has given me a better understanding of how to layout structural systems and draw efficient structural plans. Also be advised that most contractors will often ask "How come I have to put in all these holdowns in when the guy down the block didn't have to?"

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Richard Wilken
Architect-owner
R.B. Wilken-Architect
Pacific Palisades CA
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As an architect and civil engineer (specializing in structural design of buildings), sometimes when I see some other engineers' plans for houses, I agree with the contractor that the structural plans are overkill.  Residential Type V construction is a different animal than most commercial buildings, and requires an engineer who is versed in the nuances of residential buildings.  As the codes become more stringent, sometimes the engineer's hands are tied, but frequently engineering residential buildings is more of an art form.  I don't have any specific advice for your current projects, but in the future I'd recommend using an engineer with lots of Type V experience.  You might ask the (complaining) contractor which engineer he has good experiences with in the past.


Best of luck!

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Patrick Marr AIA
Patrick Marr, PE, AIA
Santa Barbara CA
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Sally Anne Smith AIA
Smith Architectural Studio
Carmel CA
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While Some contractors may be savvy about construction and have done structural  framing, sizing, etc. for years,  I always tell them that whenever they get a Structural Engineering License to practice, then come and talk to me about questioning regarding the framing, etc.done by your  structural engineer.   Each project is different in size, shape, location and orienration.  Just  because the Contractor built it, or framed it one way somewhere else does not mean structurally it is the same in another location or orientation. Unless the contractor has that education to figure that out I can talk to them about it but the final is between the Engineer and myself as the Architect.

On the other hand, always question as to the why the engineering of a structure, if there is any question on you mind.
As you may have worked for other firms and or seen the engineering done by various other engineers you should by now be familiar with framing practices and sizes. 

The questioning should always be resolved between you and your engineer. That is part of being an Architect.
Think of you as a musical conductor or director, all the parts have to work together to produce the result you want to achieve aesthetically and economically in a built structure.

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Marcus Swed AIA
Principal
Marcus J. Swed Architect & Associates
Bellingham WA
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I would tell the builder, it is not the builder's role and position to make design specification and tell the builder to do his/her job of constructing according to the design specification as the builder shall have bidded precisely according to the specification. 

In other words, the polite form of "Shut up, do your job and build the building according to the approved set of plans". The rationale for overbuilding is out of long term durability of what is constructed. If the builder failed to price bid accurately then the builder shall eat the cost. If they can't, they are off the job and another contractor that can do the job will replace them. 

So what if your design is overbuilt. The point isn't to design to the minimum that can be gotten by. After all, it isn't about building the worst & cheapest piece of dung that can be built. 



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Richard Balkins, Assoc. AIA
Building Designer / owner
Richard W.C. Balkins, Building Designer
Astoria, OR
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Michael McLeod AIA
Michael R. McLeod, Architect, P.A.
Hampstead NC
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Trust our structural engineer. Ask yourself - "what does the contractor think that he knows about the specific design parameters for this project?" Probably nothing at all. He just remembers the last thing that he built and he may well have never seen a failure which you engineer is protecting you from and for which you might be held responsible. If the contractor insists -suggest that he re-engineer it at his expense if he is so adamant and then let the two engineers argue it out at the contractor's expense. Trust your structural engineer!

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James Anstis FAIA
Retired
West Palm Beach FL
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I have found that you need to find a structural engineer that is focused on residential projects. A commercial engineer will always over design - also have someone that is more intuitive and not strictly by the book. There are many residential details that have multiple solutions.
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Craig Isaac AIA
Architect
Craig W. Isaac Architecture
Charlotte NC
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Lisa:

Suggest you review IRCNJ Edition for framing information.  Compare what your engineer designed to the numerous tables for floors, beams over garage doors and roofs.  That will give you a basis for questions to both the engineer and contractor.

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Harold Lichtman AIA
GLP Architects, P.C.
Mt. Laurel NJ
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Lisa,

Over the 35 years that I've practiced, I've learned to a) make sure I have a good and trusted engineer and b) to stand by them, just as I expect they will stand by me.  Here's a "trick" my first boss taught me.  When a client started to tell him to change something that he had done, my boss would start writing on a piece of paper, what looked like notes about what the client was saying.  In reality, he was writing something like this:

"I _________(name of client or perhaps contractor) hereby am assuming the role of _____________ (architect, structural engineer, etc) on this project and as such will take full responsibility for the following changes to the _________'s (architect's, engineer;s, etc)  certified construction documents











Signed: _______________.
Nobody ever signed it.

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Robin Miller AIA
MSH Architects
Sioux Falls SD
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Lisa,
I've been in the same situation in the past and have a few suggestions:

1. Become modestly acquainted with the residential code and its referenced materials. Look at plywood sheathing, lumber, truss joist, and LVL load charts to get a feel for what they do to allow you to be more fluent in their application.

2. Sit down with your contractor and mark up a preliminary set of structural drawings with his/her recommended changes. Ask the contractor to back up the recommendations based upon his/her sources if possible. Ask about standard wood grades available from lumber yards in your area that will be less expensive than special order items. Look for ways to use such items as stock garage door header sizes.

3. Then take that information to your structural engineer and have a heart-to-heart. Consider a meeting with the SE and your contractor if you think that would be productive.

Not many true calculations from scratch take place in wood framed design; they're more often selections from code tables, load charts, or sometimes software-generated based upon assumptions and input that might not be fine tuned for economy.

You may need to locate a structural engineer who routinely does multi-family housing structural design. Such a practitioner will have more experience at producing economical wood-frame designs; a general SE practitioner who spends 90 percent of their time working in steel and concrete may lack that experience.

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Philip Kabza AIA
Partner
SpecGuy
Mount Dora FL
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If you're getting a lot of feedback regarding your structures being over-designed, it's important to take it back to your engineer.  Input from contractors is valuable and we take it seriously, but there's a lot of, "We've always done it THIS way" in that feedback.  The code changes, and in fact the 2012 IRC has some substantive changes based on findings that the quality of framing lumber isn't what it once was.  If your engineer can defend their design, you may be able to educate the contractor!
We want our structural engineer to design a code-compliant structure, exceeding it only if there's a specific reason.  If you think your engineer may be overly conservative, you could ask for another structural engineer's opinion.
Bottom line, we have a long-term relationship with our structural engineers because we trust them.  If I had a choice between following our engineer's advice as opposed to a contractor's, well, which is more likely to keep you from being sued?

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Clark Mente AIA
President
Mente Sowell Architects
Austin TX
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Lisa:

Be careful about the "who's right" question.  You are taking on the liability for the design, not the contractor.

In general you can expect the structural engineer to be conservative in their designs.
However you should make sure they understand the cost implications for over-designing in a residential project.
Both you and the structural engineer should be fully aware of what the code requires, in this case the current approved version of the IRC.
The contractor should not be making decisions that impact or compromise what the code requires.  And often I have found that contractors are not ware of specific-code requirements to meet wind or seismic loading.

From the architect's point of view I would recommend you become comfortable with preliminary sizing joists and roof members.
For some years I've used MaxBeam, which is a great Excel-based app for sizing residential structures: joists, I-joists, wood beams, posts, simple steel beams, etc.

Also, if you are increasing design load or decreasing deflection in floor joists to account for tile flooring, it's important to inform the contractor why that is so important. (thinset tile + too much deflection = cracked tile).

I would suggest you sit down with the contractor and engineer at the same table and go through the design.  Everyone may learn something.

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Andy Caldwell AIA
Sr Architect/Designer
URS Corporation
Washington DC
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I found that in the course of providing residential design for clients first as a moon lighter and now for these last 32 years, I have been doing my own structural engineering. I enjoyed the engineering classes in Architectural school and felt that I could do most beams myself. I had a steel book which I have updated and wood beams book from American Forest & Paper Assoc.and forged ahead. The LVL literature can help for that type of beam, and they have computer programs as well. Finding the loads is based on the code requiremets for living floors and bedroom floors. Some house were very complicated (my fault) and it took the better part of the day. Any beams that go beyond 16 feet or so I may use steel. I found that deflection controls so I solved the deflection formula for the code req. l/360" per foot of span, and came up with a simple way to find moment of inertia, which you can use to pick the beam. There is some caveats here  Now that we have 110 mph wind loading itis even more complicated. Some of these problems I have found a structural engineer who is very knowledgeable of wood frame construction and I often consult with him.

If you like the structural courses you had in school then you will have the patience to do your own work. If you need to talk about this more, email me back, and I will call you

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Theodore Streibert AIA
Streibert Associates Architects
Chatham MA
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Lisa,

I've been in the same position. My experience is that a meeting attended by both the contractor and the structural engineer is the quickest and most sure way to get to the correct answer. Again, in my experience, the SE, and the contractor for that matter, are both most likely to be flexible in a meeting. If you simply ask the SE whether the structural is over-designed, the answer is likely to be "no." Many contractors are also not used to the newer seismic requirements and find the designs to be over-sized, when they're not. Good luck.

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John Downie AIA
John V. Downie, AIA, LEED-AP
Newton MA
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