We are considering a renovation too.
Sustainability is definitely an interest, though any reno for this particular house means lots of stuff in dumpsters (unless you are a complete and delightful nutjob like Daniel Kanter). I haven’t looked too much into materials yet; right now we are earlier in the process and thinking more about square footage, energy efficiency, heating/cooling, etc. One of the benefits of the bigger renovation is to make it nice enough (and just slightly more spacious enough) that if we sell, the house won’t become tear-down and rebuilt as megahouse taking up the entire garden/lot which has been happening a lot in our neighborhood. Older houses are mostly 1,000-1,800 sq ft with small backyards; new ones are 3,500-4,000 sq ft with zero backyard. The hard surfaces exacerbate the urban heat island and stormwater drainage problems.
There's also the lens of aging parents.
Both spouse and I are lucky to like our immediate families of origin a lot. His parents are starting to have various health issues (more below). In addition to his mom’s mobility stuff, his dad technically beat prostate cancer last year but has a lot of pain sitting for car rides over 20 mins. Mine are healthy so far, but retiring in 2 years once Medicare kicks in. They want to downsize & move out of the suburb with crazy property taxes. My mom is also in the “I’ll drop everything if you need me for childcare” camp. We love them all, enough to want to move them in with us if need be, but living with/near any of them would be a whole 'nother level.
Add 1st floor half bath
Our only bathroom is on the 2nd floor of this tall, skinny townhouse. It hasn’t been a problem in the past, but last year my in-laws moved an hour away (after 10 years living on a ranch in rural New Mexico!). My MIL has arthritic knees and can’t really climb stairs anymore. She tries to downplay the pain, but it hurts. With a half bath and a sleeper couch, they could come for overnights. This is a straightforward, $3-8k project including demo of an old chimney.
And extend 2nd floor
The main body of the house is 3 stories, but the kitchen is a poorly built 1-story extension off the main floor. This would extend the 2nd story over the kitchen, adding one more room for office/flex/Spore/guest, and improving insulation/HVAC everywhere.
And extend 3rd floor including another full bath
This would support a potentially widowed parent moving in longer term, though only if they can climb stairs. Very expensive and not terribly flexible.
Build a family/friends commune
Last weekend I was exploring and found a 10-acre wooded for sale just barely inside city limits. It’s zoned for 6 houses, across from a 300-acre nature preserve that runs a forest nursery school, 0.5mi from an extensive riverfront bike path… one foot in the city and one in the woods. Build a few homes, parents can hike to their hearts’ content even if they can’t see well enough to drive, shared shop building, maybe a rental apt above it… Yeah, this would be nuts.
We had an architect and a design/build firm come out, with the idea of hiring one to do schematic design for all 3 options. Then we will use those to get construction estimates and pick a path. The architect has about 6 yrs experience, recently started his own practice focused on tiny townhouses like ours, and came in at $2,500 for this prelim design work. This would likely get built by the contractor who did a great job on our backyard for a fair price. The design-build firm has 20 yrs experience and a lovely track record; they are freaking craftspeople but might be too expensive both for design and build. They’ll get back to us with the quote this week.