TLDR: If you live in San Francisco and have windows, please consider signing this letter.
I need to replace my front window. The wood is rotten. While San Francisco never gets that cold, all the cold there is whistles in through the gaps.
In general I want to make my house a little bit more energy efficient whenever I replace something. I'd assumed I could find some nice looking double paned replacements and get on with my life. Sane jurisdictions even require certain levels of insulation for this kind of project. San Francisco went the other way. There is a 14 page guide to the requirements. Which boil down to window originalism, if your house is old enough:
"Another significant difference is that vinyl, fiberglass, and aluminum windows often do not have an important detail that is common on most older wood windows: the Ogee (pronounced Oh-jee) lugs at the bottom of the top sash (also called the meeting rail) of a double-hung window."
Yes, when Meta and Red Hat cancelled their conferences in San Francisco I'm pretty sure it was the lack of Ogees.
What about some double paned units?
"There should be an interior space bar, preferably of a dark color, within the insulated unit that visually divides the interior and exterior grilles."
This relates to divided light windows (i.e. you've got multiple panes of glass in one window). You might want to just have a single double paned window, but no, it needs to be in keeping with the original. You might then think that you could put some wood details over that single window but no, just in case someone looks closely and at an angle there has to be a shim inside to simulate it being multiple individual panes.
Doesn't the city care about the environment at all?
"While the advantages of double-paned windows are well known, a properly weatherstripped, single-glazed sash window can greatly reduce or eliminate air, noise and air infiltration (where most energy is lost)."
Greatly reduced is doing a lot of heavy lifting here. Looking at U Values here, the rate of energy transfer in watts per square meter per Kelvin (1°C = 1K) – W/m2K, old single pane windows are over 4.8, modern double paned are 1.3 and triple paned 0.8. Lower is better, almost four times better just for double paned.
I don't know exactly how these requirements came into force. It could be out of touch planners wanting windows for a more civilized era. Maybe there is a concentrated benefit / diffuse cost thing going on in favor of a few eye wateringly expensive custom window builders. But when you're trying to pretend that single paned windows are a boon to the environment something has clearly gone very wrong.
Even at the aesthetic level I'm not sure we need all the Ogees. I love the chaotic architectural chaos of San Francisco. The hot pink victorian next to the grey brutalist remodel. It's part of the charm of the city. Also, the expense of complying with what was popular 100 years ago cannot help with affordability, a key challenge.
Happily my supervisor, Myrna Melgar, has proposed legislation to shred this document and allow most people to choose replacement windows that best fit their needs. It looks like her proposal is currently on a three month vacation with the planning department. If you have windows and live in San Francisco you should probably care about this, and you can sign a letter to show your support for the change here.
Updated 2025-05-03 17:06:
This passed!!!
