Why is My House Like This?
They Weren't Hung Backwards
For years, I thought there were two things you needed to know about the original windows on the front porch at House 173.
There were thirteen of them.
And they opened the wrong way.
At least that's how it seemed to me.
Unlike the familiar double-hung windows throughout the rest of the house, these were hinged windows. Open one and the whole sash swung into the porch.
Into the chairs.
Into the plants.
Into whatever happened to be sitting on the sill.
Into you, if you weren't paying attention.
They looked nice. I'll give them that.
But after living with them for years, I eventually described them on this blog as constantly being in the way and not particularly weatherproof. In 2011, we finally replaced all thirteen.
I wrote about that project here:
At the time, I didn't spend much time wondering why the windows opened inward.
I mostly wondered why anybody thought that was a good idea.
But our last Why Is My House Like This? investigation established that the enclosed porch itself makes considerably more sense once you look at it through the eyes of someone building a house in the 1920s.
So perhaps I owed the windows the same courtesy.
Why did the original porch windows at House 173 open inward?
Turns out, somebody didn't simply hang them backwards.
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| The original porch windows at House 173 opened into the room. I lived with them for years before finally asking the obvious question: Why? |
First, These Weren't Really "Backward" Windows
The first thing I learned was that a window hinged on the side and swinging like a little door has a name.
It's a casement window.
That probably isn't news to anyone who has spent more time studying windows than I had when we bought House 173.
But casements have been around for centuries, and historically they could be built to swing either outward or inward.
There's a wonderful piece of evidence from 1911, well before House 173 was built.
The Encyclopædia Britannica article on joinery describes casement windows as sashes hung along one vertical edge, essentially functioning like glazed doors.
And then it says something important.
They could open outward.
Or inward.
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| An inward-opening casement wasn't somebody's mistake at House 173. This 1911 illustration shows that the arrangement was a recognized method of window construction years before our house was built. |
An accompanying 1911 article is here:
So whoever built the porch windows at House 173 wasn't necessarily improvising.
Inward-opening casements were a recognized form of window construction.
That answers one question. Unfortunately, it immediately creates another...
Why choose them?
Because Inward Wasn't Necessarily Better
Here's where the investigation took an unexpected turn.
I assumed there would be some wonderful forgotten reason why inward-opening windows were clearly superior on a porch.
There isn't.
In fact, people knew about their disadvantages more than a century ago.
That same 1911 joinery article points out that inward-opening casements were difficult to make completely watertight.
Which immediately caught my attention.
Because that's exactly what I complained about at House 173.
They weren't weatherproof.
More than a century ago, a technical reference was essentially saying:
Yes.
We know.
And there's more.
In April 1920, House & Garden carried an advertisement for casement-window hardware aimed specifically at sun parlors.
Just for fun, you gotta check out the digitized issue here:
The advertisement actually argues that sun-parlor casements should swing outward, because inward-swinging windows interfere with things inside the room.
Things such as draperies.
Plants.
Screens.
Sound familiar?
Apparently I wasn't the first person to discover that a window swinging into a furnished sun porch can be something of a nuisance.
People were complaining about essentially the same problem before House 173 existed... I find that strangely comforting.
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| A 1920 ad was already making the case for outward-opening sun-parlor windows because they didn't interfere with curtains, screens or plants. Apparently our problem wasn't new |
So Why Would House 173 Do the Opposite?
Now we're getting somewhere.
If builders knew outward-opening casements had advantages, why would someone install thirteen inward-opening ones here?
This is where we have to separate what we know from what the house suggests.
I haven't found the original window order.
I haven't found the builder's specifications.
And nobody left a note inside the wall saying:
George will eventually wonder about this. Here's why we did it.
So I can't give a definitive answer.
But there are several possibilities.
And one makes considerably more sense than the others.
Look Outside the Window
An outward-opening casement needs somewhere to go.
That sounds obvious until you look carefully at the front porch at House 173. These weren't ordinary windows installed in an ordinary wall.
They were part of an enclosed porch.
Depending on the original exterior configuration, outward-swinging sash would project beyond the porch wall.
That creates its own problems.
Anything outside the window; screens, storm sash, trim, architectural details, shrubs, people walking close to the porch; has to coexist with the arc of that window.
And wind suddenly matters. An open sash sticking outside a building becomes a pretty effective sail.
An inward-opening sash doesn't have that particular problem. It swings into a protected space.
The tradeoff is obvious.
The window doesn't interfere with the outside.
Instead, it interferes with you.
Nearly a century later, I can confirm that portion of the design worked flawlessly.
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| Maybe the best way to understand an inward-opening window is to stop looking inside and look at what an outward-opening sash would encounter outside. |
Then There Were Screens
Screens complicate the story.
An outward-opening casement can have its insect screen mounted on the inside because the sash moves away from it.
An inward-opening casement generally needs the screen on the exterior side, or some other arrangement, because the sash needs clear space to swing into the room.
That relationship remains true in modern window design.
And on a porch designed around fresh air, screens mattered.
As we discovered in the last installment, the whole point of surrounding a sun porch with operable windows was the ability to open the room dramatically to outside air.
That story is here:
The 1921 American Builder article we looked at for that story specifically discusses glazed sun porches and shows a sun parlor with special casement windows.
The digitized issue is here, again - a fascinating read:
So we know casements and sun porches belonged together.
What we don't yet know is exactly how House 173's original screens and storm-window arrangement worked.
And that may ultimately be the missing piece of this puzzle.
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| Back porch but the answer may be hiding in the hardware. Screens, storm sash and the way these windows were mounted could tell us why the sash needed to swing toward the room. |
There Was Another Advantage: You Could Reach Everything
There's one practical advantage of an inward-opening window that's easy to overlook.
Open it and the outside face of the glass comes to you.
You can clean it from inside.
You can reach the hinges.
You can reach the glazing.
You can inspect the sash.
You don't have to lean outside the building to work on it.
Window cleaning was enough of a concern in the early twentieth century that the 1911 Britannica discussion of double-hung windows specifically mentions the difficulty of cleaning exterior glass and notes that manufacturers were developing mechanisms that allowed sash to reverse or pivot for easier cleaning.
So accessibility mattered.
With thirteen porch windows, it might have mattered quite a bit.
Imagine washing thirteen windows from both sides.
Actually, don't.
I've done it.
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| Awkward when trying to arrange furniture. Rather convenient when trying to reach the outside glass. |
And Remember What This Room Was
This may be the most important part.
We're judging these windows from the way we eventually used the porch.
Furniture.
Plants.
Decorations.
Things sitting near the windows.
But what if the people who selected them weren't terribly concerned about any of that? A sun porch was supposed to be opened up.
The 1921 American Builder article described the glazed sun porch as practically an additional room and emphasized light and ventilation.
A 1919 house description from Oklahoma, for example, described a living porch or sun parlor equipped with broad casement windows specifically so the room could live up to the idea of a sun parlor:
Casements offered an important advantage over conventional double-hung sash:
you could open essentially the whole window opening.
A conventional double-hung window can normally expose only about half of its opening at once.
Swing a casement aside and almost the entire opening becomes ventilation.
Multiply that by thirteen.
Now we're beginning to see what these windows could do.
Open enough of them and the enclosed porch could become something remarkably close to an open porch again.
Maybe the person who chose them wasn't terribly worried about where we'd put a chair ninety years later.
They wanted air.
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| Thirteen casements could transform an enclosed room into something remarkably close to an open porch. Suddenly those old windows begin to make sense. |
The Answer Is Probably a Compromise
So why did the original porch windows at House 173 open inward?
The most accurate answer is:
We don't know for certain.
But now we know considerably more than we did when we started.
Inward-opening casements were an established window type long before House 173 was built.
They weren't necessarily superior. Period sources openly acknowledged some of their disadvantages, including exactly the problems we experienced with them.
But they also made sense in certain situations.
They allowed almost the entire window opening to provide ventilation.
They kept the swinging sash within the protected porch rather than projecting outside.
They made the exterior surface of the glass accessible from inside.
And their configuration may have worked with whatever screen, storm sash or exterior arrangement originally surrounded the porch.
Most importantly, they belonged to a room whose purpose was somewhat different from an ordinary room.
I spent years looking at those windows individually.
Perhaps whoever designed the porch was thinking about all thirteen of them together.
Closed, they made a room. Open, they helped make it a porch.
That's a pretty clever trick.
It doesn't mean I want them back. Let's not get carried away. I remember those windows. But I understand them a little better now.
And that's really the point of this series.
Sometimes an old house isn't asking us to admire everything somebody did nearly a century ago.
Sometimes it's simply asking us to understand why they might have done it.
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| The original windows are gone, and I don't regret replacing them. Understanding why they worked the way they did doesn't mean we have to pretend they worked particularly well. |
The Next Mystery
Why Do Old Houses Have Plaster and Lath Walls?
The porch windows were easy to see.
The next mystery is hidden behind the walls.
Throughout the original part of House 173, the walls aren't made from modern drywall. They're built from narrow strips of wood covered with layers of plaster.
The wood strips are called lath.
And if you've ever opened up an old wall, you've probably seen the result: thin wooden slats, rough plaster keys squeezed through the gaps, and a wall surface that seems both remarkably durable and completely mysterious.
Why build a wall that way?
Why not simply cover the framing with boards?
Why go to the trouble of applying several layers of wet plaster?
And why did this method remain so common in American houses for generations?
Plaster and lath weren't just an old-fashioned substitute for drywall.
They solved several practical problems at once.
They created smooth, finished interior walls.
They helped control drafts.
They offered some resistance to fire.
They could follow curves and irregular surfaces that would be difficult to cover with rigid panels.
And when they were properly installed, they produced walls that could last for a century or more.
But they also came with their own complications.
Plaster can crack.
Lath can loosen.
Repairs can become archaeological digs.
And every time we want to run a wire or open a wall, we have to figure out exactly what we're dealing with.
There's a lot more behind those walls than a layer of old white plaster.
That's the next mystery.
Related House 173 Posts
This is the essential House 173 source for the story: the original windows, their inward-opening operation and their eventual replacement.
A much more recent close look at the construction and details of the enclosed porch.
Sources & Further Reading
A particularly useful period technical source explaining casement and double-hung window construction and specifically documenting inward-opening casements.
Public-domain technical illustration of an inward-opening casement.
Includes a period advertisement discussing casement-window operation specifically in connection with sun parlors and the practical advantages of outward-swinging sash.
Includes “Sun Parlors and Sleeping Porches,” with period discussion and photographs of glazed sun porches and casement windows.
A period house description specifically describing a living porch/sun parlor equipped with broad casement windows.
Hey, thanks for stopping by - see ya' next time!
Keywords
inward opening windows, inward opening casement windows, old porch windows, historic casement windows, 1920s windows, sun porch windows, enclosed porch windows, old house windows, vintage window design, casement window history, 1920s house architecture, House 173, historic wood windows