Any one have examples for what has been used for service size for a speculative retail plaze building?
In KVA per square foot (or amps with voltage). I have a good idea and examples but I would like to compare.
Specifically in this case I am sizing a service for a 15,000 square foot single story strip plaza type building.

For a crude estimate, I'd look at an existing similar property .... and if that other place is more than ten years old, double it!

A few other points to consider discussing with the speculator:
- If the place has less than six units, I would still argue for the extra expense of using a buss gutter. This will save lost of money later, when meters are added, etc.
- Make allowances (extra junction boxes, etc) for shifting lighting circuits and switches around. Lay out your lighting patterns so as to accommodate remodels, as walls get moved around.
- Allow in your bid for exhaustive documentation, and identification, of every circuit- to the level of marking every box and device.

Such steps will pay off big time later, when remodels and maintenance are necessary.

I know, there's likely lots of pressure to do as little as possible, to keep the price as low as possible. You need to resist this. I guarantee that every time there's a change of tenant, you will be moving lights, adding receptacles, etc. When a poor (cheap) job is done at the start, the entire property quickly becomes a dog's breakfast ... and each remodel becomes sloppier, and takes longer.

This is why, for such places, I prefer a 'skeleton' of pipe, with MC (or romex, if you must) 'whips' going into the wall cavities.

I am talking about an empty shell. No tenants yet. All we need is the service. These are built all the time.
Does everyone just look at the last similar building they did?

This kind of strange. a 15000 sq ft could take a 1000 amps but to sell a single space of 15k sq ft is rare. No one is going to want one service in the plaza. You place a 200 amp service at one end to provide "white box" power and then get with the power company on how you can provide separate power to separate units. The last 15000 sq building we did had 600 amp 3 phase, but this is light for some tenants,

I have done a few of these; the problem is restaurants, hair salons and over zealous engineers. Simons properties who builds strip centers and malls all over the country allows for 15va per foot, then if the tenant wants more power they can pay to have a service brought in for their space. Locally it’s required to fill the secondary compartment of a pad mounted transformer and bring all the spares to the building for future use, to facilitate any future use or need.

For Shell Space ONLY.
15va x 15,000sf / 830 = 271a or a 400a HV service which is more than they really need and will cover your house panel, lot lights and a few of the over zealous engineers too.

Option (1) I like do a single service for each building with a gutter, house panel, lugs and a tap box for the tenants. Put a lock on the gutter and set up a connection fee for the tenants to keep their booger eating morons they hired to do their electrical work from screwing up your gutter lugs. Generally I charge $350 for final connection and if they bypass me then they own the warranty for the building service.

Option (2) I set the disconnects, meter cans, and install empty conduit up and into the building, and still charge a final connection fee. No meter, no wire, the tenant furnishes the wire and I charge $350 for final termination.

Option (3)
I bring a 100a HV service to each space and set a disconnect, the building owner picks up the expense of the meter and wire, and there is no connection fee.

Option (4)
Same as (3) only I set panels and xformer, and usually some lay-in lights and a few receptacles. The owner picks up the meter and utility fees. There is no connection fee on my part.

Work hard to get the finish out of these spaces; they are the gravy of the project.

15VA/SF is pretty low esp. if you expect restaurants (which you have to assume may be a tenant). I would say 25-30VA/sf is pretty conservative. In my case the developer had a similar building that had a 1200A, 480V which is twice as much. The developer wants to be prepared for anything but I think that is but that is pretty high.

I started looking at specific examples of tenants and 15KVA/sf is not too small. On the other hand the developer did mention a tanning salon in addition to a restaurant. Anyone know what a typical tanning salon uses?

We had to upgrade a service for a tanning salon and I think it went to a 400amp 3 ph and just covered it. Check how many beds they will have plus A/C and heaters. There were alot of heating type loads that added up quickly. Rod

Now wait a minute read the OT.

Note the words:





Nobody said anything about restaurants or tanning solons, and if you go in guns a blazing “speculate’n” about 25-30va a foot calculations, then you can watch your client shop your number for a better speculation. Start off with 15va for retail space then when they bring a restaurant in work up a price for it, anyone who has ever developed retail space knows that some tenants have bigger electrical needs and they know they aren’t free, and how to make those tenants pay for them.

To answer the question someone here asked the last tanning salon in a retails space I built had a 400A 120/208V 3Ø service.

ITO - The developer (owner) is asking for something like 60W/sf. I am looking for backup to tell him it is too much.
And he (the developer) said that they could get a restaurant, tanning salon etc.

I did a quick geussiment of a tanning salon with 5 beds and came up with right around 200A which means it would probably be a 400A .
How many beds are there in a typical salon?

Even with a tanning salon, restaurant and a small store or two I think the load would still work out to around 20W/sf.

Let's look at this the way an insurance company might.
That is, using the 'law of large numbers.'

Look at a few existing projects that are similar in size. See what sorts of tenant mix they have ... perhaps 2 'heavy' users, 3 'moderate,' and 7 'light.' See what their demand is ... perhaps the PoCo has some data. Perhaps up these figures by 10% for future growth, or an atypical mix.

Customer shopping your numbers? That's where you need to sell the value of your leg work.

Sure, the NEC wold allow you to use 3VA / sq. ft... giving you a 480v service of 100 amps .... but who are we kidding? Remeber what the NEC says about its' not being a design manual!

I'd visit existing, similar places at the busiest part of the day, and measure with an amp-clamp ... for a quick guess.
For a more exact estimate, I'd have to give the specific plans, knowing the tenants, a close going-over.

As luck would have it, our local news today announced the 'demolition date' of one of our shopping centers. This center, simply put, had been dying for 15 years. A large part of the reason was that the original utilities were grossly inadequate, with many, many 'band-aids' applied over the years. They simply could not serve the tenants that they wanted.

When I sign off on a set of calculations, I am saying 'this is my judgment.' I have to make the best guess I can. If some other fool, chasing the bottom dollar, wants to sign off on a marginal set of numbers .... well, that's his reputation, not mine.

15va x 15,000sf / 830v = 271a or a 400a HV

20va x 15,000sf / 830v = 361a is still a 400a HV service

We can even back into it and a 400a HV service is 22va/sf...

Just for grins, here are some real numbers from plans laying around in my office. I have a stack of about 100 more retail stores with what I suspect are similar numbers.

Banana Republic- 16w/sf
Old Navy- 12.3w/sf
Bicycle Sports Shop- 9.5w/sf
SunglassHut 12.5w/sf
Bombay Clothing- 15.5w/sf
Ann Taylors- 13w/sf
Talbots- 20w/sf

Recent strip mall, utility service at each end; 14 stores. 800, 3 phase, 208 at each end. 200 amp to each space. All were plain vanilla boxes; 8-2x4 fluor; 6 recept, 3 exit combos, 5 gal wtr heater, bath exhaust fan/lite, 3 ton HVAC (gas heat), sign circuit, rear wallpack light.
Tenants; Subway, Krauzers, Cleaners, Furniture, Indian Rest., Dollar store, Nail Salon.....and yes, a Tanning Salon. The Salon was increased to 400 amp, 208.

Other ones I have worked at (larger store spaces) had 400 A, 480 each, out of 2k switchgear.

John

The owner wants 480V. How would you set up the service for a house meter and provision for tenant meters?

That gets a lot trickier. One meter will need to feed a 480V panelboard that feeds a transformer that feeds a 120V panelboard to deal with the Owner's 480V and 120V house power.
The other meters will feed the tenants who will likely want strictly 120/208V for their stores. Most POCO rules don't want a transformer on their side of the meter, so each Tenant will end up with a transformer...

If you can't change the Owner's mind about the 480V, see if you can get the POCO to give you (2) Service drops...480V and 120V.
That way there are no transformers to mess up the layouts, since most Tenants are very defensive about losing square footage for anything that doesn't add to their bottom line.

I think the owner is set on providing 480V period. The only advantage I see to the owner is a lower cost for the secondary to th building. Did I mention that the service will be on the out side of the building. I have never seen a 480V service for this small of a building so I am not picturing how this would be set up for tenant meters (as opposed to just a current transformare cabinet for one meter).

It’s not difficult or tricky, and is pretty much a preferred method in my neck of the woods.

You furnish:
Primary Conduit and pole riser or manhole penetration; pull string only.
T-Pad w/grounding
Secondary Conduit and Wire
Main Disconnect (local critera may apply here, if its less than 6 handles this is not required in some areas)
CT Can
Meter Can
Tap Box (unless you’re AJH will let you do taps in the gutter)
Tap Blocks
Gutter that is long enough to accommodate all the tenants meters
House Meter Can
277/480V House Panel (100A 12-24ckt) For building lighting, signs, and lots lights.
9kVA Transformer
120/208 House Panel (100A 12-24ckt) For Receptacles, heat trace and misc.
(Note: you can do a powerzone 120/208V panel with a transformer built in but they can be hard to get and are expensive)

All the tenant meters are HV glass meters in a can, they come out of the gutter into a disconnect, to a meter (some areas hit the meter first then a disconnect) then to the lease space to disconnect or a MCB panel depending on your local criteria.

Depending on the deal you make, either you or the tenants furnish the service to the lease space and each space gets their own transformer and who furnished the lease space service is also negotiable. This is all SOP for tenant finish out, and most tenants especially national chains want HV service.

Not sure how the POCO works up there but getting a HV and a LV service to the same building does not happen here.

I would think for this size the 25w/sq ft is about right. This size would probable accomodate 3-5 tenants, all of which probably aren't tanning or food. The standard 100A retail should balance it out. Much larger spaces go down (w/spft) because of divesification; smaller goes up in demand, CYA. Plus, figure your exterior lighting, probably 100A @ 3ph 480 w/ small low voltage. Service to a gutter w/ taps - it's prelim.

I just looked at a few buildings here in town. While these were commercial/industrial rentals .... the typical tenant has a two room office in front, with a warehouse / shop / garage taking up the bulk of the space, I really liked the way the service was set up.

(Total building volume was about 22,000 sq ft, with each space maybe 1700 sq ft on average).
There was an electric room, which held a meter and disconnect for each unit.
Within each unit, there was a 480 panel, a transformer, and a 208/120 panel. Everything was surface mounted, so access was easy.

Thanks for the input.
Let me paraphrase ITO:
800A main disconnect.
Tap box/tap block
gutter
House meter
277/480V house panel
10KVA 1 ph xformer
120/240 1ph house panel (I think the only thing that may be on this is a heater for the water service hot box).
My local utility requires a disconnect ahead of a 480V meter. But this building is not local for me (it is NiMo I think).
What 100A (or 200A) 480V meter will give a short circuit rating above 10K?
What am I missing?

How is the service being metered?

Gutter needs to be N3R and long enough for all the tenants.

I don't think your meter has anything to do with available fault current; around here we don't select or furnish a meter, that part is all done by the poco. We just install an approved meter can that the poco sell us or is sometimes furnished to us as part of the permit.

I mean the meter socket.
I.E. a Cutler Hammer 100A meter socket has a short circuit rating of 10KA.

Hmmm I have never bought one from a supply house, we get ours from the poco in my area.

CGW:
Your utility have any "approved" meter stacks?

We have run 600 to 1600 into a Sq D stack. 3 phase, 4 wire, 277/480 with 200amps to each tenant space. 100 amp 480 feed to 75 kva xfr to 42 circ 120/208 w/200 or 225 MCB.

For anything above 200 self contained (w/CT cab) a plug-in section w/?? MCB to CT & then to space.

Our utility requires 'cold sequence', so main before CT/Meter.

John

They may or may not put a tanning salon in. I was thinking that a typical salon may have 5 beds. Was I off. I understand they probably would have more like 30 or more. Here are some numbers:
Tanning Salon 3000 SF, 160,000VA
Bar/Rest 4000 SF, 100,000VA
Remaining 8000SF, 20VA/sf - 160,000VA
That's 505A at 480V.
So 600A would work. 800A would be conservative. 1200A would be ridiculous.
What do you think?

If you do not know what is going into the lease space, and your client does not either, its completely ludicrous to design for ANY load that may or may not go in there. You are either doing a budget, or a bid and if you plan on all the worst-case scenarios then you will be too high and wont get the work.

The solution is very simple, plan on an agreed upon VA per SF, in this case 22 worked well for a 400A HV service, then make sure you bring in your empty spare conduit from the service transformer to where you can use it later as provisions for any restaurants and tanning salons.

I have done enough of these to know that all restaurants and salons know they will have to pay for upgrades to the service to build out their lease, unless they make their deal on the front end of the project being built, and even then they still pay something to get it done. This is where your provisions from the transformer come in, if they are needed.

If the client wants 60/SF then price it and give it to him with a VE for 22/SF so when he thinks you are way too high and shops your number at least he has your VE before the next guy gives him a VE just like it.

Just my two cents, we could site around continue to mentally masturbate this to death but the fact is if you don’t know what is going in these spaces and you want the work, then the solution is a clear scope with an agreed upon va/ft, provisions for more (empty conduit) and a contract that states all this.

HotLine1 - Does Square D have meter stacks rated at 480V?

Sq D has 480 volt, see Section 9 of Digest
Class 2755, 2756 or 2710.
You MUST check with your utility first for ANY mfg equipment. CH/Siemens, etc are also available.

John