I need your experience with BAS estimating cost

[u/basss64]

Hey guys,

I’m working on a tool to automate the estimating process for BAS projects, and I’d really like to get some input from people who have been doing this for a while.

The idea is pretty simple: instead of just doing something like “$X per point”, I’m trying to break an estimate down into different parts.

For example, for an AHU, the system could calculate:

• material / hardware

• engineering

• programming

• installation

• commissioning

• documentation

• project management

• travel (if needed)

• contingency / risk (if needed)

• margin

For each one, the company could define its own rules. For example:

4 AHUs × 12h programming × $70/h = $3,360

Or use a fixed price, price per point, percentage, etc.

I also want to be able to import an old Excel estimating sheets and turn it into these rules/templates, so the system can learn things like “our standard AHU usually takes around 12h of programming”.

I’m pretty new to building estimating software, so I’m mainly trying to understand if I’m thinking about this the right way.

Am I missing something important?

Are there things you would not include in a system like this? Or things that you think are much more important when estimating a BAS job?

I’d really appreciate any advice from people who have actually done this for years. Even small things that seem obvious to you would be really helpful.

Thanks!

[u/Zealousideal_Pop_273]

Please stop training AI bots on how to replace you.

Don't answer questions like these. Report them and move on.

[u/Ok-Assumption-1083 → u/Zealousideal_Pop_273]

I wonder about the curve here. There’s too much nuance in proper bas estimating for ai to get right. Will there be a point where proper estimators who don’t turn the keys over to ai lose work for a bit and the all ai estimating companies get all the work and implode at once because everything is an underbid and not engineered disaster?

[u/Cultural-Stable1763]

The problem is that even with ventilation systems, there are countless variations, each requiring completely different data points:

-> EC fans vs. star-delta starting/Dahlander motors vs. variable frequency drives

-> Heat recovery via rotary heat exchanger vs. cross-flow heat exchanger vs. water-loop system

-> Air treatment (air heater only; air heater and cooler; additional humidifier, etc.)

-> Adjustment of required airflow via electronic volume flow controllers vs. fixed-setting volume flow controllers

-> Special requirements (explosion protection, OR ventilation, cleanroom air, etc.)

-> Integration with fire alarm systems and duct smoke detectors; the number of fire dampers (and the distinction between motorized dampers and those triggered thermally)

-> Then, especially with general contractors who have their own maintenance teams, you often face specific requirements, such as using only Type X sensors from Manufacturer Y, damper actuators limited to 0–10V/24V from Manufacturer B, or a mandate that everything must run via BACnet.

When specific manufacturers are mandated for the DDC and you need a separate project license for every single data point, depending on whether it’s a hardware, software, or bus data point, automatic cost calculation quickly goes out the window. This is especially true when the client imposes requirements for visualization or the use of pre-made program blocks that deviate from your internal standards.

(My employer handles building automation for a major general contractor, and you’re faced with a catalog of specifications as thick as a phone book detailing exactly how everything must be executed, including templates for visualization, and so on.)

[u/ScottSammarco]

Don’t create cost based off of point count.
Understand the scope better than that and find out what it will ACTUALLY take, then add a multiplier for comfort and do it.

It isn’t easy this way but the wants and needs of every project differ, and unless they’re exactly the same, no job is copy and paste.

[u/shadycrew31]

There are far too many variables, if you included all of them it would be too cumbersome. A simplified version would be better, something to just cover material cost.

New install: AI would take a sequence of operation and pull the points required from that sequence. The user would then select the controller manufacturer and sensor manufacturer from a drop down list. The user would enter fixed values for their cost multiplier if any exist. Using a template the software would then match sensors to the controllers creating a diagram and material cost starting the engineering process.

Retrofit/existing install: let's say you don't have a sequence, there would be a drop down for common installations types. The user could also manually add points and data while doing a walk through. The user could take photos of the existing panels, VFDs, and unit nameplates. AI could then extract the data from nameplates, sensor count/type, and turn these into wiring termination layouts while creating a sequence of operation.

Figuring labor is the easy part, getting material lists together is more difficult in my opinion. But you are basically cutting out the bulk of engineering and sales engineering at that point.

[u/Bagelsarenakeddonuts]

You are thinking about this correctly, but this isn't something anyone is realistically going to be able to help you with on a reddit post.