This is block by block. Long ago Seattle asked home owners on each block to foot the bill to run gas. Many blocks said yes, some said no. For blocks where only 1 side was developed, the cost was higher and there was a greater chance of everyone saying no. That is what happened on the street I grew up on, when the city had asked everyone to pay for gas lines, there were so few houses on that working class block that it was cost prohibitive for everyone to pony up how much $ would have been needed.
So instead people had oil furnaces installed and now that block will at some point require serious environmental remediation. :/
I have a long term interest in full electrification, but find the process daunting due to the interlocking set upgrades. Between insulation envelope upgrades and electrical system upgrades, there is a lot of potentially disruptive work needed to even allow permits to be issued for heat-pump HVAC and water heater or fully electric kitchen.
If the internal wiring also needs much work, it threatens to be almost as invasive as a gut renovation. Then, I ponder what other work we'd want to piggyback on it. But then it all sounds too much for life and budgets, so we procrastinate...
I think the area got off pretty light from the 2001 quake and the pace of retrofits has been too slow, but has had fortunate timing so I think things won't be too bad for the next quake, depending on exactly where it hits.
I would have a separate unit for the basement and the first floor though; we do have zoning dampers, but it's not very effective and the basement gets too cold.
Propane deliveries are expensive, if starting from scratch, I might have wired for electric clothes drying and water heating. And I would have probably gone with owned tanks instead of the current system where the delivery company owns the tanks. Electricity prices doubled in the last 5 years, but propane may have gone up more.