Clerestory Windows Went In Today

In the past week the things that have been happening haven’t been all that photogenic – skim coating is something you have to experience in person, wood floors is just more of the same, etc.

But one thing that’s new and different is that the clerestory windows were put in today – and we’re liking them a lot…

clerestory window 3rd floor

The windows let in light from the bulkhead (“light scoop”) on the roof. The one above is on the 3rd floor and lets light into the den / TV room. Light actually goes both ways – in the mornings the morning light hits the front of the building and light goes from the rooms into the stairwell.

The clerestory window on the top floor is actually quite tall and lets in tons of light in the early afternoon (almost too much light)…

clerestory windows 4th floor

Because the wall is a fire wall with a 1 hour rating, the glass has to be fire rated as well. We had two options – spend $5,000 for special clear fire rated glass, or spend $900 and get wire glass. Spending $4,100 for clear glass didn’t make sense to us, so the glass is wire glass…

clerestory window with wire glass

The wires don’t really bother us. We were mostly concerned about the frame – we wanted it to be really minimal – we’re happy in that respect…

Window Glazings Have A Pronounced Effect

Since the windows have gone in Dan has been noticing that the window make the rooms feel a little dark – that they block a fair amount of light. He’s commented that it feels a bit like wearing sunglasses.

We actually have three different types of glazing on the building. All three are on the back of the building…

Back of our townhouse - 3 types of window glazingStarting from the bottom, the rental unit has what Gaulhofer calls G28 glazing – which is their standard glazing. 80% of visible light is transmitted through the glass, but only 23% of UV gets through, and 62% of “solar heat”. (The more “solar heat” you block the lower your A/C bills in the summer, but the less help you get with heating in the winter). We use that glazing on most of the front of the building as well.

Going up one floor to the parlor floor security was important and there we have “smash proof” glass which Gaulhofer calls “G50”. That lets through 78% of of visible light, but only 4% of UV, and 58% of “solar heat”. Blocking the UV is important since it means artwork won’t fade, but we’re not sure how it will affect our plants. We use that same glass on the roof and on our kitchen window in front (the other locations where security might be an issue).

The top three floors we use a fairly aggressive glazing (Gaulhofer’s G23) since, unlike the lower windows, there will be no shade and it’s a south exposure (the deck shades the tenant, and the pergola will shade the parlor floor). G23 only lets through 61% of visible light which explains why Dan feels like he has sun glasses on in those rooms. Like the G50 glazing it only transmits 4% of UV, and solar heat gain is a lower at 42%.

Thing is, the sunglasses effect would actually be worse with American-made windows. For example if you look at Marvin Windows (considered the best big American window company), a PDF on their site shows their windows typically only transmit 40 to 50% of visible light. A few get up to 57% but those are somewhat inefficient windows that don’t qualify for tax credits. Our most aggressive glazing transmits more visible light than Marvin’s least aggressive glazing, and some of our windows transmit twice the light of some Marvin window.

Because Marvin blocks so much light, they also block more “solar heat” – typically only 18 to 33% of solar heat gets through a Marvin window. That difference between the manufacturers reflects the difference in their markets. Most of the US is hot and bright in comparison to Austria and northern Europe where most Gaulhofers are installed. Gaulhofers excel at insulation (the “U Factor”) which is the critical component in a cold climate. So our energy bills would be lower if we had gone with Marvin, but that just is what it is – we like the trade off we made and prefer more visible light transmission.

The sunglasses effect is only really an issue for us because we’re now accustomed to the house with no windows. If we had only known the house with windows installed we probably wouldn’t have noticed it. But the glazing you choose for your windows does make a difference both in your energy bills and your experience living in the house (how much light you have in your rooms) – so choose carefully.

One thing I should add… You may think “we live in a fairly cold climate, wouldn’t solar heat gain be a good thing since it reduces winter heating bills?” I thought the same thing, but the bottom line is electricity for A/C is far more expensive than gas (or oil) for heat, so you should favor lower SHGC values.

And another thing – if you research it you’ll find recommended values for NYC, but they’re averages. Realize that the north side of your building will only get light in the morning. SHGC just isn’t important for north facing windows. The U-factor (good insulation) is far more important for north facing windows. So go for low SHGC for south facing windows and high U-factors and high VLT (visible light transmission) for north facing windows.

Back Of The House Looking More Complete

Nearly all the windows are in now and the back of the house is looking more complete. Here’s a before picture…

Before shot of the rear of our Harlem townhouse shell

And here’s what it looks like now (in dim light and bright light)… We’re still getting used to the color Dan picked for the rear windows.  😉  In bright light the color is so bright it almost glows. In dim light it’s just cheery. While I probably would have chosen a more conservative color, in a city where everything gets dingy and dirty, I sorta like the brightness.

back of renovated townhouse in dim light back of renovated townhouse in bright light

Needless to say a HUGE improvement over where we started. It’s still not the final look though. We’re adding a deck with a pergola plus fall protection bars on the windows, and a roof deck railing. Here’s the drawing for the deck and pergola…

Deck with pergolaThat’s just 4 of the 5 stories (6 if you count the cellar, 7 if you also count the windows in the bulkhead at the roof deck). Here’s the entire wall from a different perspective – you can see where the deck will go…

Back of townhouse with new windows in place

The dividers in our tilt-n-turns do make your mind think double hung – so that part is true to the objective, though I still wish we didn’t have to have the dividers.

[If you’re wondering, parts of back wall (to the right in the pictures above) still need to be power washed. Long story, but it wasn’t completed when they did it the first time.]

Otherwise there are huge stacks of sheetrock in our place at the moment…

Piles of drywall in a townhouse under renovation

But before they can start putting drywall up they need to finish off all the little stuff – electrical, plumbing, low voltage wiring, etc.

Our Gaulhofer Windows Arrive, Installation Begins

FINALLY the truck arrived this morning with our windows. We ordered Gaulhofer Windows, which are made in Austria. Yeah, I know… American jobs, and all… But the Europeans just make a better window (when you read the details below realize we got some of Gaulhofer’s least expensive windows – and they’re probably better than the best American windows)… And I really wanted tilt-n-turn windows…

It took a couple hours to off-load the truck and then the guys had to get the windows all sorted. But by the end of the day they had installed two windows in the back of the building…

Gaulhofer doors installed in Harlem townhouse

We couldn’t go as contemporary as we were hoping with the windows… We were hoping the windows would just be one huge piece of glass, but in order to get our tax credit for historic preservation we had to put a divider in the middle of the window to make them look like traditional double hung windows. Luckily the original windows in our house had two huge panes of glass so we only needed the one divider. We also had to have panels in the doors to give a nod to the house’s original doors…

Paneled Gaulhofer doorIf you look at the bottom of each panel you’ll see the protective metal strip that Gaulhofer puts on its wood windows. That was another thing we had to get past historic preservation, but they liked the fact that the metal strip will make the windows and doors last longer, so with the proviso that we’d color match the metal as best we could, they said “OK” to it.

One thing I do like is how big our windows are. They let a lot of light into the building. What you see below will be the bedroom for our renter with a door out to the garden. There will be wrought iron gates on both the window and the door to make our tenant feel more secure.

Window and door installed in Harlem townhouse rehab

Gauholfer window open like a casement windowWhat’s cool about Gaulhofer windows is that they’re tilt-n-turn windows. What that means is that they open like a regular casement window (see pic to the right). That was really important to me. Just before we left our coop we had the windows in our apartment replaced. We had a couple of those 1920s/1930s corner windows and I still remember how stunning the view was with the windows removed. The view with the window in paled in comparison. There was just this expansiveness when there were no windows in.

While we don’t have the incredible view we had in our old coop, I wanted that connection to the outdoors you get when there’s a huge gaping hole when a casement window’s open. You can never get that with a double hung window because there’s always glass in front of you. Not so with a casement or tilt-n-turn – you can have the ENTIRE window open.

One thing to note is that American casement windows swing out. European casements swing in. The issue is that many of the American casements are impossible to clean unless you can get outside – which is impossible in a 5 story townhouse. Marvin does have a way to get to the other side of the window, but it’s pretty cumbersome. With a European in-swing casement it’s really easy to get to both sides of the window. The only downside is that it makes window treatments a bit of a challenge. But if Europeans can live with that limitation, we can too…

Gaulhofer window tilted in at the top.The tilt part of tilt-n-turn can be seen in the pic to the right. For practical reasons you often want ventilation, but you don’t want a huge gaping open window. To that end tilt-n-turns tilt in at the top to give you fresh air – even when it’s raining outside.

Now you can see why historic preservation required the divider in the middle of the window. Since the windows operate nothing like double hungs they at least need to look like them when they’re closed. But it would have been really cool to have one big huge pane of glass… Would have given more of that connectedness to the outdoors that I like so much.

As far as the color choice – it’s a little bight, but I find it sort of cheerful. (It looks better in person than it does in pictures.) It just seems to have good karma to it when you see it in person… However, on the front of the building we’re using this chocolate color that will look incredible against the brownstone (it will be slightly darker and redder than the brownstone)… Here’s one of the chocolate windows, but it hasn’t been installed yet…

Chocolate colored wood window from GaulhoferThat color is in stark contrast to the orangey-yellow color in the back. The chocolate is sort of a sexy and sophisticated color where those terms would never be used for the orangey-yellow color. Given that the rooms in the front of the house are darker and more somber while the rooms in the back are south facing and bright – the colors sorta match the moods of the rooms. The only room where you see both simultaneously is the parlor floor.

One thing that I’m sure will provide years of confusion is the locking mechanism on Gaulhofers… I unlocked the door to the garden and then it took me 15 or 20 minutes to figure out how to get it locked again. Gaulhofer uses a multi-point locking system. When you lock the door it’s locked top, bottom and middle. It’s far superior to American doors which just have locks in the middle of the door. What took me 15 minutes was discovering that the key isn’t what you use to lock things top and bottom. You have to take the handle and pull it up. That locks it top and bottom and THEN you lock the lock which keeps all the locks in locked position. Very confusing and god forbid we have house guests and forget to explain how to lock the front door 🙂

Related to that, the foreman was worried there was a problem – the hinges for the door to the roof were on the outside of the building. He was concerned that someone could take out the hing pins and get into the building. But it doesn’t work that way… If you take out the pins there are two other locking points in the middle of that side of the door which prevent the door from being opened (see pic below). Plus you can’t really take out the bottom pin – you lift the door off it – which you can only do when the door is open. The only problem we could have is if someone took the pin out the door might drop the next time we opened the door normally.

Locking point on side of Gaulhofer doorGaulhofer also makes what they call a “vault door” which is a glass door that’s  about as completely impenetrable as you can get… Bullet proof glass, steel reinforcing throughout the door, etc. Our roof deck doors just have “smash proof” glass. You can take a baseball bat to them (please don’t) – they’ll crack, but you won’t get through – security without bars…

I’m really excited to have the windows in. It’s sort of a milestone in the project – it means the building is finally getting closed up and we’re clearly past the mid-point in the project…