UPDATED for 2021
So you've looked all over and can't find something that is just right for you and are now starting to think about building your own home from scratch. Buying off the shelf saves a lot of time, but if you just have to have the right sized living room for your Austin powers couch, then this is what it's going to take.
I have permitted and built over 60 homes in Austin, TX since 2011. Since then the process has changed some, and the costs have changed significantly, but many things are still very much the same. At a high level it's going to take you probably about a year from idea to move in if everything goes normally. Here are the main steps you need to tackle and some of the challenges at each step you will face.
Finding a lot Time: 30 days
Cost: $150,000 to $600,000
As of this writing, there are 177 lots in the city of Austin. If you want a home that is under the median home price (Currently ~$650,000) and around 2000 sqft, you are going to need to get the dirt for around $200k or less. There are only 30 lots that meet that criteria. If you exclude Lakeway, there are 16 left all in far east Austin. Half of those are in a flood plain. So finding the land is going to be one of the most challenging parts of your journey. This excludes creative approaches like sub-dividing and building multiple units to reduce the cost per door. Realistically you will end up buying a tear down and building in an area where the exit price is equal to the land cost plus the build cost.
Because of the limited supply as well as the equity requirements from a lender to secure a construction loan, most land purchase offers at this price point are made in cash. This means you could find and close on land within 30 days. Most of this time will actually be taken up with your due diligence to make sure you can build what you want on the property. This is a lengthy topic, so perhaps I will do another post on that later.
Designing your home
Time: 30 days
So you will need to submit a design and permit request to the city of Austin before you can build. A licensed architect will be able to create the plans required for the permit. You will start with a site plan which lays out where the building will sit. Assuming you are zoned SF-3, this space can consume no more than 45% of the total land area, including driveways and anything that is impervious cover. And no that really cool permeable concrete stuff still counts toward your coverage.
An architect will take several weeks to develop a set of plans, and as a custom home owner this may consume more than 30 days as you tweak the designs. When I was spec building, we fixed the designs and didn't mess with them much because we wanted to move quickly.