topic Re: Equivalent Single Dwelling calculation in schedule? in Project data & BIM

Equivalent Single Dwelling calculation in schedule?

Mikey_B — Tue, 28 Jul 2026 00:27:53 GMT

Aloha,

Our jurisdiction is now requiring that we calculate and report the ESD (water usage) using this formula:

ESDs = [1.15(Baths)^1.3 + Beds + 3] / 10

Is there a way to have a schedule do this calculation after inputing the number of bedrooms and bathrooms?

Operating system used: Mac Apple Silicon Ventura 13.5

Re: Equivalent Single Dwelling calculation in schedule?

Barry Kelly — Tue, 28 Jul 2026 00:43:22 GMT

Schedules can not d any calculations other than simple summation of columns/rows.

Classification and Properties can be used though.

Look at Properties with expressions where you can create a property with this formula.

https://help.graphisoft.com/AC/29/INT/index.htm?rhcsh=1&rhnewwnd=0&rhmapid=#t=_AC29_Help%2F045_PropertiesClassifications%2F045_PropertiesClassifications-9.htm&rhsearch=properties&rhhlterm=properties&rhsyns=%20

There are also many posts here.

You would need a property for the number of beds, another for the number of baths and then a third to do the calculation.

You could than associate these to a zone for the apartment area where you can adjust the number of beds/baths for each zone and then get the resulting calculation.

You can then schedule the resulting property or even use it in a label you can add to each zone in plan.

Barry.

Re: Equivalent Single Dwelling calculation in schedule?

Mikey_B — Tue, 28 Jul 2026 04:06:11 GMT

Barry,

Thanks so much for the detailed reply. I had created properties for the bed and bath count but got lost trying to create the expression. The link you provided looks like it will be very good guidance.

Thanks again,

Mike

Re: Equivalent Single Dwelling calculation in schedule?

Barry Kelly — Tue, 28 Jul 2026 05:52:11 GMT

The expression will be exactly as you have shown it here.

I am assuming the (Baths)^1.3 means bathe to the power of 1.3

Mathematically I would write this as (Baths)^1.3

So in my case because the properties are in a group called 'JWH Settings' ....

( 1.15 * ( {Property:JWH Settings/baths} ) ^ 1.3 + {Property:JWH Settings/beds} + 3 ) / 10

The problem is in the property expression, it will not allow the power to be a decimal number.

It must be a whole number.

I see there is a 'POWER' mathematical function, but this does not allow decimal power value either.

I am not sure how you would get around this.

Any mathematical geniuses out there?

Barry.

Re: Equivalent Single Dwelling calculation in schedule?

Lingwisyer — Tue, 28 Jul 2026 06:50:43 GMT

Can you just put a division in brackets? ie. (Baths)^(13/10)

Re: Equivalent Single Dwelling calculation in schedule?

Barry Kelly — Tue, 28 Jul 2026 07:03:14 GMT

Nope, I tried that.

The 13/10 still equates to a decimal value which it doesn't like.

Barry.

Re: Equivalent Single Dwelling calculation in schedule?

Lingwisyer — Tue, 28 Jul 2026 07:14:11 GMT

There is a "nth root" function. Try (nthroot(bath,10))^13

Re: Equivalent Single Dwelling calculation in schedule?

Barry Kelly — Tue, 28 Jul 2026 07:34:08 GMT

That seems to work, thanks @Lingwisyer .

For 2 baths and 3 beds I get 0.88.

Would that be correct @Mikey_B ?

Barry.

Re: Equivalent Single Dwelling calculation in schedule?

Mikey_B — Tue, 28 Jul 2026 21:16:34 GMT

Barry,

Yes, that looks correct. The county online calculator rounds up to 0.9. I'm thinking I can control the decimal places by adjusting the Calculation Units for the schedule?

Re: Equivalent Single Dwelling calculation in schedule?

Barry Kelly — Wed, 29 Jul 2026 01:33:34 GMT

Yes but that will affect all schedules.

Plus I am not sure if it round property values.

There is a rounding function in the property expressions.

You just need to put that formula in the rounding function.

ROUND ( insert_formula_here, 1 )

Barry.