Talking To An Architect

I've gotten to a point where I thought I'd talk to an architect to see if building an ADU in my backyard makes sense. So I made an appointment for a phone consultation with Jennifer Kretschmer, an Architect who often posts on the San Jose ADU Facebook page with answers to our group's befuddled questions.

Jeniffer has put together "The Home Design Project Planning Pact" which I highly recommend. You can get this pact and other free advice on her website: https://www.jkretschmer.com/get-advice

It was an enlightening conversation that made me realize building an ADU is not for the faint of heart. Jeniffer said that given the age and condition of my garage it would need to be torn down. The cost to rebuild from the ground up would be $500 per sq ft. and if I did some of the work myself would save me at best 20% of the total cost.

So doing the math, 640 sq ft. x $500 = $320,000 - 20% DIY= $256,000

At 500 sq ft, the ADU would cost $250,000 - 20% DIY = $200,000

Since I would be doing this for my daughter there would be no rental income stream and the payback could very well be beyond my lifetime.

So what are my alternatives?

Since converting the garage is cost-prohibitive I seem to have three choices:

1. Don't build an ADU and just upgrade the garage

2. Tear down the garage and in its place use a prefabricated ADU

3. Tear down the garage and build a Wikihouse

Upgrading the garage is the easiest and perhaps the most logical, but my daughter is going to be disappointed. Then again she has a roof over her head so let's be thankful.

Using a prefabricated ADU has its advantages but the cost is still, when all is said and done, $350 per sq ft.

This leaves option three, the Wikihouse, a CNC machined jigsaw puzzle that is being used around the world for its low cost and ease of construction. Here's a pic of the Wikihouse Microhouse, a 495 sq ft. one bedroom backyard home that can be built in five days. Note this just includes the framing but can be done with a couple of people who have no construction experience.

The cost to build this micro house runs from $100 to $150 per sq ft and maybe more but certainly less than the $500 per sq ft being charged in the San Francisco Bay Area.

Even at $200 per sq ft, the Wikihouse would cost $100,000 to build a 495 sq ft ADU. Now that's something to think about!