[Bldg-sim] Energy Model Cost

Nick Caton ncaton at smithboucher.com
Thu May 12 18:55:31 PDT 2011


Interesting discussion!  I'll avoid the vintage debate... if you guys are a finely-aged bottle of wine, that just makes me grape juice =)!  

 

"Good" energy models can encompass a range of accuracies/expectations...  

1.       On one hand, some clients require the models match "reality."  This desire sometimes needs to be tempered with the unknowns of new construction & future performance, but given enough historical data a well-calibrated model is certainly approachable.  "Calibrated modeling" has nothing to do with LEED-NC.  

2.       On the other hand, forward-thinking design team members will approach me to isolate specific measures and compare their impacts in a relative fashion to make informed energy-conscious design decisions.  In this case, nobody cares whether the rest of the model is anything other than a "from the hip" estimate, but it's up to the modeler to determine what variables deserve extra attention for their effects on determining the outcome.  A "good" model in this context delivers quick answers which are accurate in a relative sense, isolating the correct variables.  "Preliminary modeling" is a very distinct skillset, is often based on little "real" data, and requires a different mindset to indentify all the variables in play so as to isolate what's not critical to the study at hand.

3.       Somewhere in between these extremes lies the realm of "LEED models."  LEED-NC models can be characterized as 'prescriptive guesswork.'   They are based on design decisions made (but NOT reality).  EPAcT and code-compliance modeling are similar in this regard.

 

Each mode of modeling requires different time investments, each has marketable value, and one can be an expert in one mode of modeling while being inexperienced in another.  

 

If I were asked:  Is it feasible to construct a model that will survive the rigors of a LEED review and earn a lot of points in 80 working hours?  The answer is yes, it's definitely feasible.  The actual number depends heavily on the complexities of the proposed design as others have explained well enough, but for a simple enough project, 1 to 2 working weeks could easily be more than enough.  I'd reinforce the earlier points to add a fluff factors if you're unfamiliar with the process or systems involved.  

 

That said:  A "good" LEED model is in my definition simply one that earns a lot of points after review/approval.  A good design helps "good" LEED models happen, but the reverse isn't true. 

 

 A "good" model in the context of "accuracy nearing reality" implies a much higher caliber modeler and an extended timeframe.

 

I take a firm stance that LEED/90.1 are not a means of enforcing "reality" upon a model.  To rephrase/reinforce:  a LEED model is not a "real" model.  The sole function/purpose of a LEED model is to earn LEED points.  Now, that's not to say a LEED model during its creation is not of some use to the design team, but such models are frankly most efficiently put together after the design process is well under way/finished.  

 

The intent of EAc1, in my opinion, dances between two commendable goals:

1.       Design buildings that use less energy

2.       Get an energy modeler on the team to inform the design, helping to achieve goal #1

 

Problem is, 90.1 Appendix G is not a guideline/standard for how to inform design.  EAc1/EAp2/90.1 as currently constructed is a metric for assessing the performance of the final design, after the critical decisions are made.  That's why "LEED models" are best built after design is (mostly) complete, and that's why "LEED models" make for a flawed approach to guiding early design.  In the course of a LEED project, I am always a part of the design team (typically directly involved in electrical/mechanical design), and will often construct "preliminary" models along the way to guide the process where questions come up across disciplines.  These models bear little resemblance to a final LEED model, but help the design move in a direction that actually saves energy.  This is very different from the documenting performance against an arbitrary baseline.  As a result of this early involvement, getting lots of EAc1 points later is a simple matter of correctly modeling the actual design, not "finding points."

 

I can't offer much regarding hourly estimates to the independent consultants out there... Rather than charging an hourly rate for modeling services rendered, I am typically embedded in the design team, and said efforts are rolled into "design hours."  Modeling generally isn't billed separately, but rather treated as value added to our design services.  Hours spent on modeling is not the critical figure here, though it can be extensive in scope - what's important is the repeat business we get from very satisfied clients, both inside and outside of LEED.

 

Hope some of that helps!  It's mostly my current perspective  - I reserve the right to change my mind =).

 

~Nick  

 

 

 

 

NICK CATON, E.I.T.

PROJECT ENGINEER

Smith & Boucher Engineers

25501 west valley parkway

olathe ks 66061

direct 913 344.0036

fax 913 345.0617

www.smithboucher.com 

 

 

From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of John Aulbach
Sent: Thursday, May 12, 2011 6:46 PM
To: Carol Gardner; sheffer at energyopportunities.com
Cc: bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] Energy Model Cost

 

OK, Carol..now you threw the "bait" out there..older than dirt, eh?

 

I have done very limited LEED "type" modeling where you compare 20 walls and 40 windows types (well, it seemed that way). Correct me if I am wrong, but a Base model must be built to comply with a certain level of ASHRAE 90.1 (now up to 2010 ??). With all of the nuisances of eQuest 3.64, I am going to build the model from scrathc and put in all the relevant baseline data in by hand.  And, by the way, the ASHRAE baseline model might be an entirely different system.  I am just completing an EPACT evaluation (ASHRAE 90.1-2001) and the Baseline HVAC was screwe chillers, whereas the Actual building was packaged units with Turbocor compressors (ask me how I did that).

 

It very much depends on the complexity of the building. A 40,000 sf office or a 500,000 sf hotel with casino facilites.

 

I am unfamiliar with the LEED paperwork to be filled out after the modeling has been done. But I would not do anything of this type in under 120 hours, preferably 160 hours. If the client thinks he can do better, let him.

 

Contingency, contingency.

 

We won't discuss how old CAROL might be..

 

John A.

 

-----Original Message-----
From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Eurek, John S NWO
Sent: Thursday, May 12, 2011 5:04 PM
To: Omar Delgado; bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] FW: Energy Model Cost

 

I agree with some points already stated.

 

1.  Existing buildings have existing information.  A LEED model is a lot more

of an art.  There are a lot of judgment calls.  And just as often, the

guidance you receive on what to assume is just wrong.  (I was directed to

model a church as 100% full each Sunday for 3 services.  That is good for

equipment sizing not for an energy model.)

 

2.  The design assumes certain equipment, but the LEED model can't be

complete until the you receive the submittals to find what equipment is

actually purchased.  To do it right, changes during construction should be

added to the model.

 

From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Carol Gardner
Sent: Thursday, May 12, 2011 4:59 PM
To: sheffer at energyopportunities.com
Cc: bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] Energy Model Cost

 

Marcus,

You have inadvertently hit upon why IBPSA worked with ASHRAE to create a BEMP certification. That's Building Energy Modeling Professional (BEMP). 

Some of us who have been in the field for awhile began to worry a couple of years ago when so many new energy modelers began appearing on the listserv with questions. Their questions indicated a lack of training and experience that was worrisome. What made it worrisome was that they didn't seem to realize that they were as inexperienced as they were; they didn't appear to be pursuing training to learn how to do what they were doing; and we were uncertain as to how or if they were practicing quality control. We hoped that by creating a path to certification that we would give clients one more qualification to look for in their modelers.

If you have been in this industry for any length of time, and by industry I mean the overall construction industry, you know that you don't get a lot of chances if your work doesn't pan out. If your energy model says I have a LEED Gold building and I'm going to save $4,000/year and what I really get is LEED Silver and $1,000/year, I am not going to be happy. So, I will probably not give you any more work but, even worse for all of us, I'll start expressing doubts about the whole process. LEED - what is it good for?

So, now we all have more training, right? We read our ASHRAE Handbooks and technical manuals so we know how to model the difficult stuff. We can find any topic in the DOE2 Manuals, all of which are one line, available, and easily searchable. 

So now we are so good we can do these models in 40-80 hours. Really? Not me and I've been doing it longer than everyone, except you, John Aulbach. So I'm going to join Marcus in his rant because he's on to something.

It's up to us to not under bid this work. It's up to us to educate our clients about the importance of quality in this process. If they think they are getting the same analysis in 40 hours that they used to get in 120 hours, they need to be led around to rethinking that and to be reminded that GIGO.

Cheers,

Carol


Thu, May 12, 2011 at 2:31 PM, Marcus Sheffer <sheffer at energyopportunities.com> wrote:

	In our experience a final model, done right, would take about 80 hours.

	 

	WARNING - frustrated modeling rant to follow:

	 

	Doing just a final model however completely misses the point as to why we model - it is to guide design decisions!  

	 

	If I saw this RFP and all it asked me for was a model to determine LEED points, during or after design, I would try to educate the potential client about the purpose of modeling.

	 

	Unfortunately too many projects pursuing LEED are only doing the minimum when it comes to modeling and almost completely missing all the benefits.  Too often the "market" transforms only based on a least first cost denominator basis that results in little real transformation.  Doing models to determine LEED points does not transform the market, save any energy, and just circumvents the purpose behind LEED. (the next version actually requires design phase modeling!)

	 

	Any "modeler" who does only final models without attempting to explain to the owner why this is a bad idea should be "drummed out of the corp" in my humble opinion.

	 

	The problem is that if you respond to this RFP with 120 or 160 or more hours to really do the design phase modeling right, you will go up against the "modeler" who claims to be able to do it in far less time.  So how do we get the folks who issue the RFPs to ask for a proper scope of work so that they can compare fees on a level playing field?  It is unfortunate that we are even having a discussion about doing modeling work in opposition to its purpose.

	 

	Sorry for the rant but I feel better now. J 

	 

	Marcus Sheffer

	Energy Opportunities, Inc/a 7group Company

	1200 E Camping Area Road, Wellsville, PA  17365

	717-292-2636, sheffer at sevengroup.com <mailto:sheffer at sevengroup.com> 

	www.sevengroup.com

	 

	From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Demba Ndiaye
	Sent: Thursday, May 12, 2011 4:28 PM
	To: Omar Delgado; bldg-sim at lists.onebuilding.org
	Subject: Re: [Bldg-sim] Energy Model Cost

	 

	Omar,

	 

	I would expect, for a building this size, approximately 40 hours (multiply by your hourly rate). The 40 hours include EAp2/EAc1 LEED documentation, and any review you may have to respond to later.

	 

	Now, given that you have never done a LEED model, it will take you more time, possibly up to 40 more hours.

	 

	HTH,

	 

	_______________

	Demba NDIAYE

	 

	From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Omar Delgado
	Sent: Thursday, May 12, 2011 7:08 PM
	To: bldg-sim at lists.onebuilding.org
	Subject: [Bldg-sim] Energy Model Cost

	 

	Greetings everyone,

	 

	I have a question regarding the cost of an energy model for a LEED project. Every energy model I've done so far has been for 

	existing buildings, mainly for optimization purposes. However, I received an RFP to model a five-story, 41,500 sq. ft. building

	that's currently on the design phase and is pursuing the LEED-NC Silver certification. I really have no idea what would be a fair 

	price for this model since I'm going to have to use Appendix G (ASHRAE 90.1) to evaluate the difference between the base 

	and proposed buildings. I don't know how much extra effort this will take. I know the procedure, just haven't done it before.

	 

	Can you shed any light on this issue?

	 

	Thanks in advance!

	 

	Omar A. Delgado Colón, P.E., MEnvM., LEED AP BD&C

	Vice President

	EnerMech

	PMB 340

	130 Winston Churchill Ave.

	San Juan, PR 00926-6018

	Cel. (787) 224-6537 <tel:%28787%29%20224-6537> 

	odelgado at enermechpr.com

	info at enermechpr.com

	www.enermechpr.com <http://www.enermechpr.com/> 

	 

	 

	 

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-- 
Carol Gardner PE

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