Hey John; it's EXTREMELY viable given a few key factors...... Here's some stuff to consider....
1. Gotta know what you are doing re value building. Pricing out all the right materials form the start is key.
2. Also sounds like you know the size of house but gotta make sure where you build that the zoning is proper as well as any applicable deed restrictions that may make what you want to build possibly not an option.
3. Are you an experienced builder and know the ins and outs of developing a property to make it "build ready"? Dirt work? Utility Costs? Development fees? etc...
4. Price of Building plans? -- Don't know your area and required design and engineering requirements. These can hurt a new build's cost efficiency where you have to build to the most recently adopted building codes. I have found even as a builder in many areas it is better to buy existing just for this fact alone!
5. Time - do you have the time if you are not an experienced builder to dedicate to being at the job and learning the ins and outs of ground up construction?
6. Financing - if you have inexpensive means or cash to do the build yourself, great.... If not, may find it hard to get a bank to finance you if you can't demonstrate a proficient history of like-kind construction.
If you can get the dirt cheap enough and the corresponding comps in the area in which you desire to build substantiate such a move,,,,,, AWESOME! Just have to make sure you compose a list of all possible corresponding development costs and run the numbers along wth evaluating the risk factors, especially based your building experience. If you are experienced as such, this will help you dial your numbers in tighter. If not - one thing you will have to realize that you will probably have new construction subs trying to get in your shorts a bit more preying on any inexperience they may sense you have with new construction and the corresponding costs. Sometime, new construction (depending on circumstances) can be cheaper concerning number of trades, but again, that's an experience thing...
Maybe you can network yourself into an experienced builder and he/she could give you some est cost per sf building prices for a normative market price house for your area of focus...
I do build and hold as I can build "at-cost" and I buy usually "distressed" dirt and also subdivide to value add even before building... This is an area of specialty for me... Being able to build NEW and hold is great IF the numbers work out for your particular circumstances...
Hope this little bit helps you evaluate things a little more clearly!
**Sorry for any typos!-- was typing faaaaasstt!
Best of Luck,,, Rob!