Builder wants window trim, architect says go trimless — rowhome. What would you do?

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:Go with whatever is more waterproof.

Yes, you're looking for ease of maintenance, not a fleeting trend.

OP here.

About waterproofing — definitely agree that's priority #1. That said, my plans already call for:

* ZIP-R sheathing (integrated WRB + insulation)
* ZIP flashing system (tape and liquid flash)
* Rainscreen assembly (drainage mat)

So from what I understand, the actual waterproofing is handled at the sheathing layer, not the siding or exterior trim. The siding is essentially decorative and part of the outer cladding. The rainscreen adds a pressure-equalized drainage plane behind it.

Wouldn’t trim vs. no trim mostly impact appearance and install complexity—not true waterproofing—especially if the flashing is done right?

More than happy to hear pushback if I’m missing something.

I’m starting to think the builder prefers trim because it hides imperfect siding cuts and makes installation easier, whereas a trimless approach is more technical but aligns with the clean, modern and luxury look.

Windows by there very nature are penetrations into the sheathing layer. I would proceed with caution - particularly if your builder is pushing back. I'm a believer in architects, but boy do they get things wrong sometimes. Not saying this is a case - I'd need to see details in all installation conditions - but I would listen to your builder (who I'm hoping has seen those details).

[Anonymous]

Anonymous wrote:

Anonymous wrote:Listen to your builder, who is thinking about practicality and durability. Your architect is thinking about how a photo of the job will look on his website.

Most architects are idiots.

Harsh, but architects do lack practical judgment -- a friend lives in a house previously built and occupied by an architect, who didn't like the look of gutters

There’s no problem with no gutters - plenty of high end custom homes are surrounded by French drains. It’s a more complicated design and requires more site work but it’s not automatically a problem.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:Go with whatever is more waterproof.

Yes, you're looking for ease of maintenance, not a fleeting trend.

OP here.

About waterproofing — definitely agree that's priority #1. That said, my plans already call for:

* ZIP-R sheathing (integrated WRB + insulation)
* ZIP flashing system (tape and liquid flash)
* Rainscreen assembly (drainage mat)

So from what I understand, the actual waterproofing is handled at the sheathing layer, not the siding or exterior trim. The siding is essentially decorative and part of the outer cladding. The rainscreen adds a pressure-equalized drainage plane behind it.

Wouldn’t trim vs. no trim mostly impact appearance and install complexity—not true waterproofing—especially if the flashing is done right?

More than happy to hear pushback if I’m missing something.

I’m starting to think the builder prefers trim because it hides imperfect siding cuts and makes installation easier, whereas a trimless approach is more technical but aligns with the clean, modern and luxury look.

bulk water management should be done by the cladding (siding/trim) not by the drainage plane, which is a backup that manages drying of bulk water and moisture on the backside of the cladding

That's simply not true in modern homes. The primary water management strategy is the drainage plane — i.e., the fully sealed ZIP-R layer behind a ventilated rainscreen. The siding and trim are part of a screened cladding system — they shed most bulk water, yes, but the actual waterproofing happens at the sheathing layer.

That’s why products like ZIP, Delta-Vent SA, or even Prosoco liquid systems are used with open-joint claddings and rainscreens. They’re built to handle water intrusion behind the siding and dry quickly, which wouldn’t be possible if the siding was expected to be watertight on its own.

This is why modern stuff is terrible and doesn’t last. The old, sturdier ways are better. Modern is designed without practicality in mind, or to fail so you need to redo it in 20 years. Avoid stupid errors like relying on marketing from product salesmen.

100%

Simple old school exterior surfaces. All this new stuff is garbage.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:Go with whatever is more waterproof.

Yes, you're looking for ease of maintenance, not a fleeting trend.

OP here.

About waterproofing — definitely agree that's priority #1. That said, my plans already call for:

* ZIP-R sheathing (integrated WRB + insulation)
* ZIP flashing system (tape and liquid flash)
* Rainscreen assembly (drainage mat)

So from what I understand, the actual waterproofing is handled at the sheathing layer, not the siding or exterior trim. The siding is essentially decorative and part of the outer cladding. The rainscreen adds a pressure-equalized drainage plane behind it.

Wouldn’t trim vs. no trim mostly impact appearance and install complexity—not true waterproofing—especially if the flashing is done right?

More than happy to hear pushback if I’m missing something.

I’m starting to think the builder prefers trim because it hides imperfect siding cuts and makes installation easier, whereas a trimless approach is more technical but aligns with the clean, modern and luxury look.

bulk water management should be done by the cladding (siding/trim) not by the drainage plane, which is a backup that manages drying of bulk water and moisture on the backside of the cladding

That's simply not true in modern homes. The primary water management strategy is the drainage plane — i.e., the fully sealed ZIP-R layer behind a ventilated rainscreen. The siding and trim are part of a screened cladding system — they shed most bulk water, yes, but the actual waterproofing happens at the sheathing layer.

That’s why products like ZIP, Delta-Vent SA, or even Prosoco liquid systems are used with open-joint claddings and rainscreens. They’re built to handle water intrusion behind the siding and dry quickly, which wouldn’t be possible if the siding was expected to be watertight on its own.

This is why modern stuff is terrible and doesn’t last. The old, sturdier ways are better. Modern is designed without practicality in mind, or to fail so you need to redo it in 20 years. Avoid stupid errors like relying on marketing from product salesmen.

100%

Simple old school exterior surfaces. All this new stuff is garbage.

If new houses were built as well as older houses from 50-150 years ago, they'd cost 3-5 times as much also.

If someone wants a good house these days that will last more than a century, they have to DIY or subcontract it.

[Anonymous]

This is such a weird discussion and not really answering the question besides some people like old houses and others new.

[Anonymous]

We need to see section details of window and wall. Trim was used for a reason - covers up the intersection of two systems.
No trim calls for an exacting install and fit.
Again. Need to see details.

[Anonymous]

I would go with what your builder feels more comfortable with. Unless you want to find another builder. It sounds like he doesn't have high confidence in his ability to waterproof well with the trimless.

[Anonymous]

Anonymous wrote:Are you black-and-white-ifying a 100-yr old home, stripping it of its original look and period-appropriate embellishments?

If so, go with the trimless windows so your home will be on trend and look like every single other renovation in the District. High end or cheap flip, doesn’t matter as long as it has that look of a Monopoly house

OP says she's renovating a "modern rowhome," so we can assume it's not historic.

[Anonymous]

Anonymous wrote:Go with whatever is more waterproof.

This has nothing to do with waterproofing.

[Anonymous]

What siding/cladding are you using?

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:Go with whatever is more waterproof.

Yes, you're looking for ease of maintenance, not a fleeting trend.

OP here.

About waterproofing — definitely agree that's priority #1. That said, my plans already call for:

* ZIP-R sheathing (integrated WRB + insulation)
* ZIP flashing system (tape and liquid flash)
* Rainscreen assembly (drainage mat)

So from what I understand, the actual waterproofing is handled at the sheathing layer, not the siding or exterior trim. The siding is essentially decorative and part of the outer cladding. The rainscreen adds a pressure-equalized drainage plane behind it.

Wouldn’t trim vs. no trim mostly impact appearance and install complexity—not true waterproofing—especially if the flashing is done right?

More than happy to hear pushback if I’m missing something.

I’m starting to think the builder prefers trim because it hides imperfect siding cuts and makes installation easier, whereas a trimless approach is more technical but aligns with the clean, modern and luxury look.

bulk water management should be done by the cladding (siding/trim) not by the drainage plane, which is a backup that manages drying of bulk water and moisture on the backside of the cladding

That's simply not true in modern homes. The primary water management strategy is the drainage plane — i.e., the fully sealed ZIP-R layer behind a ventilated rainscreen. The siding and trim are part of a screened cladding system — they shed most bulk water, yes, but the actual waterproofing happens at the sheathing layer.

That’s why products like ZIP, Delta-Vent SA, or even Prosoco liquid systems are used with open-joint claddings and rainscreens. They’re built to handle water intrusion behind the siding and dry quickly, which wouldn’t be possible if the siding was expected to be watertight on its own.

This is why modern stuff is terrible and doesn’t last. The old, sturdier ways are better. Modern is designed without practicality in mind, or to fail so you need to redo it in 20 years. Avoid stupid errors like relying on marketing from product salesmen.

100%

Simple old school exterior surfaces. All this new stuff is garbage.

You clearly have no idea what is on the market or how the new means and methods are implemented. The issue is every wants to install like they have for 40 years, and that is not how its done anymore. You need change your methods along with the change in products.

[Anonymous]

Everyone is right here. It would look better trim less, but the builder is going to have a very hard time making that look good.

My husband is an architect and when we redid our house, he didn’t bother asking for trimless even though it would have fit our house look better because he knew it would have been messed up.
Our house was built in the 60s and the windows were without trim, but the addition and new windows have trim because it was beyond our builders skill set.

My advice: Do what the builder wants and knows because it could look horrible if they stretch their teams skills set.

[Anonymous]

Hope the pictures post

With trim:
https://www.houzz.com/photo/126202-greenlake-custom-home-craftsman-exterior-seattle" border="0" class="embeddedImage" />

Trimless:


Source: https://www.finehomebuilding.com/2013/02/14/modern-hardie-siding-details-w-exterior-rigid-foam

[Anonymous]

Hope the pictures post

With trim:


Trimless:


Source: https://www.finehomebuilding.com/2013/02/14/modern-hardie-siding-details-w-exterior-rigid-foam

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:Listen to your builder, who is thinking about practicality and durability. Your architect is thinking about how a photo of the job will look on his website.

Most architects are idiots.

Harsh, but architects do lack practical judgment -- a friend lives in a house previously built and occupied by an architect, who didn't like the look of gutters

There’s no problem with no gutters - plenty of high end custom homes are surrounded by French drains. It’s a more complicated design and requires more site work but it’s not automatically a problem.

French drains are a sign of failed design. This house had them, our house has them, and they mean that you're moving water from where it shouldn't have been in the first place. In our case, because the house was built on a near-swamp, in my friend's case, because the architect had A Vision.