External roller shutters as window insulation
 

Over at my Grandma's house we had external roller shutters installed a few years ago. The ribs ("laths") are two layers of metal with polyurethane foam in between. When purchasing we got the medium-thick option (4mm) as a compromise between cost and insulation value. Today I'd have gotten the thickest possible, but that was then...
Today I checked exactly how much they insulate from the cold. I closed one and left the other open as a comparison.
The indoor temperature was 17°C, outdoor was -20°C, so the differential was quite large. The windows are already double pane and argon filled, so their insulation value is already high, but adding more insulation on the outside will always help. Here is the temperature distribution for the two windows:
The external roller shutter also noticeably reduces the drafts that can be felt when standing next to the window.

These roller shutters have more virtues: In the summer they are GREAT at reducing solar gain (these are facing south), while at night they can be slightly raised to allow ventilation:
A locking mechanism at the bottom keeps them from being lifted from the outside, so it is safe to open a window for the night.

They also function quite well as storm shutters. I'm using that arguement to talk Grandma into mounting shutters on the west-facing windows, where the worst storm winds cause the windows to leak.

Our public Library has those and I've always liked them.
I also talked to a rep for a German company about 10 years back that was selling them in the US and I really wish I had kept their info because I would like to get some for my house at some point.

Any idea on the brand or cost per window?
I really wish that stores here had window shades like that, closing them up at night would help save a ton of energy and keep the windows from being broken.

How do you close them from the inside?

I wonder if building inspectors would allow the use of salvaged double paned windows which don't meet current energy efficiency standards for new windows if the salvaged windows were installed alongside insulated roll-up shutters.

The last time I checked the insulated shutters were less expensive than new windows.

I have no idea, unfortunately:( Those were installed 8-10 years ago and there is little chance that the receipt hasn't been thrown out.
A fast search of the local market suggests ~US$100 per square meter, but I don't know what level of quality you get for that price.
They might also keep the sun out of the stores windows during the day if partially closed. In many countries in southern Europe roller shutters that swing out are quite popular:
The ones at Grandma's are operated by pulling a rope. There can also be a crank to make it easier, or an electric motor. Some versions (made to be closed from the outside, like stores) use a long rod.

how strong are these? Will they stop a brick? Someone trying to kick their way through for a minute? The paranoid me wants these but they really would look out of place in town here.

I saw them all over the place in northern Europe in the late 1960s.
They were made out of steel and their main use was for security.
I believe most of them would stop a brick and could take some hard kicks..
Nowadays, I see them on some of the store windows at strip malls etc..

I think the main problem with installing them on homes in the USA would be the fire codes.

Yeah, they are actually known as 'security shutters' here and that is their main use.

About 2 years ago there was fire in someone's house here and the woman who was inside at the time couldn't get out because her roller shutters were closed and couldn't be opened without electricity, which was off because of the fire. That's one of the reasons I made sure that my Grandma's shutters were manually opened (even though the seller was set on selling the more expensive electric version).

Manual has be a lot safer, but.. I found out years ago during Navy fire fighting training,
during a bad fire, you might only have a 20 mm layer of breathable air on the floor of the room you are in..
Once you get your nose on the floor boards, you can inhale some cool air.
Getting up to operate any kind of device, means you have to be able to do it, by feel and very fast..

The house I rented in Sohren, Germany in the late 80's had those shutters. I worked a rotating shift over there, so if I wanted to sleep during the day, I could lower the shutters almost closed and it made it nice and dark. We also closed them at night to make the rooms more comfortable.