#20-2026 Ed May – A Discussion about all Things Passive House – Part 2

I'm not sure it's a conflict, but it seems like jurisdictions on the residential side have a difficulty understanding HVAC design with regards to

passive

house.

And typical manual J, D, and S don't seem to work as well with a super low load home.

True.

And when you take a load calculation When you take basically a passive house planning package or something to a jurisdiction and say, we want to use this to size the equipment in the house.

It's like, I don't even know.

I have no idea what I'm looking at as a code of.

Yeah.

That's a really good point.

Right, right, right.

So yes, so I should maybe qualify what I was saying before.

So when we do code compliance, we have never, ever tried to use the Passive House models for code compliance.

Essentially, you end up redoing all that work.

So as you say, on the residential front, maybe you do a res check or an ecotrope model or something.

uh on the commercial scale maybe you do a com check or you do an ashray model you end up doing a separate compliance model in parallel that that satisfies the jurisdiction's requirements and so yes you end up kind of doing both of them there are teams out there and then as you rightly point out in all of our projects we would also do a manual j uh s you know, maybe a D, probably not a D, but at least a manual J and an S, um, if it's a small residential or something like that.

So you're doing, you're doing multiple models in parallel using, using them for their specific purpose.

So you do a passhouse model for passhouse compliance.

You do a manual J for heat pump sizing.

You do an ASHRAE model for code compliance, right? So there's different, different, different needs for the different models.

Um, And so, yes, you're right.

That is always the case.

There are teams out there.

There are some people out there who are working to try and get alignment.

And there are some jurisdictions like Massachusetts, for instance, where you can, in certain cases, use your Passive House model for compliance.

I'm not sure it's a conflict, but it seems like jurisdictions on the residential side have a difficulty understanding HVAC design with regards to

passive

house.

And typical manual J, D, and S don't seem to work as well with a super low load home.

True.

And when you take a load calculation When you take basically a passive house planning package or something to a jurisdiction and say, we want to use this to size the equipment in the house.

It's like, I don't even know.

I have no idea what I'm looking at as a code of.

Yeah.

That's a really good point.

Right, right, right.

So yes, so I should maybe qualify what I was saying before.

So when we do code compliance, we have never, ever tried to use the Passive House models for code compliance.

Essentially, you end up redoing all that work.

So as you say, on the residential front, maybe you do a res check or an ecotrope model or something.

uh on the commercial scale maybe you do a com check or you do an ashray model you end up doing a separate compliance model in parallel that that satisfies the jurisdiction's requirements and so yes you end up kind of doing both of them there are teams out there and then as you rightly point out in all of our projects we would also do a manual j uh s you know, maybe a D, probably not a D, but at least a manual J and an S, um, if it's a small residential or something like that.

So you're doing, you're doing multiple models in parallel using, using them for their specific purpose.

So you do a passhouse model for passhouse compliance.

You do a manual J for heat pump sizing.

You do an ASHRAE model for code compliance, right? So there's different, different, different needs for the different models.

Um, And so, yes, you're right.

That is always the case.

There are teams out there.

There are some people out there who are working to try and get alignment.

And there are some jurisdictions like Massachusetts, for instance, where you can, in certain cases, use your Passive House model for compliance.