Under the hill and far away

This has been a devastatingly cold winter in these parts. Or at least, colder than any other winter in a generation or so. Thus, the topic of insulation has been on everybody’s lips and todo-lists, including mine.

Our 120-year old 19th century-bourgoisy-apartment in the middle of the city is already pretty well insulated by Oslo apartment standards: Hi-tech insluation materials all over and dual windows which still hold their own after 120 years.  The door however, is also a 120 years old, and still has single pane glass (although of a modern anti-burglary type). In time, we will replace or refurbish the door completely, but in a historical and protected building that’s at least a €10.000 job. In the meantime, fixing those single pane glasses could really help keeping the hallway warmer and heating bill low.

So, what was the fix?

Instead of 6 complete and new, high-insulation window panes for the door (also €1500 job or more), I opted for plastics.

First item was choosing the material: It seems that both 6-10 mm acrylic glass (plexi) and polycarbonate would do the job. However, finding somebody who could simply sell me the panes online turned out to be tricky: All the european stores now routinely refuses to sell to Norway (for customs and red tape reasons ), and nationally there were no decent online shops, only physical stores which I really couldn’t be bothered with spending a full day looking up. In the end I ended up ordering 10mm polycarbonate thermoglass from a greenhouse shop (“Grønt Fokus“), which was basically the only thing available which would fit the bill.

The thermoplastic was channeled, so not completely clear — but that was not a problem on door glass which is frosted anyway. The plastic panes were also very easy to cut into size using a carpet knife and a dremel, much easier than it would be with non-channeled acrylic or polycarbonate.  The channels also made it easy to make the edges fit well (that old door does not have straight edges on it).  However, I would not have used channeled thermoplastics to add a layer to clear glass.

After cutting the plastic panes, I used a narrow universal sealing tape  around the edges to fix them on the inside.  The plastic is light, so that actually holds it fine. I left about a centimeter of air space between the original glass and the new thermoplastic pane. Finally, I sealed it all with silicon sealant all around.

The result: Warmer hallway, and no major intrusion on the how the door looks.  The surface temperature inside on the glass panes is now noticably higher to the touch, although I haven’t been able to measure the actual difference yet.  Total cost: €50.  Total improvement in insulation: Significant.

I have to say, for a long term fix, replacing the door completely is still the best way to go, and I am not sure how well the thermoplastic works for noise isolation compared to normal polycarbonate or acrylic glas, but all in all this was a pretty successful apartment hack.