I've had friends who homeschooled while building a house. If you find yourself in that situation, remember that any construction experiences your high schoolers have can count as high school credit. Woodworking, carpentry, occupational credit, etc., might be good course titles to consider. Your kids are learning while you do these things, right? Let them live and learn.
Have you read Barb Shelton's Homeschool Form + U + La? That was what her life was like. She talks about how she incorporated home construction into her transcript.
Also, the book Homeschooling For Excellence by the Colfax's might encourage you. Their family was also building a home all through high school, and both kids went on to Ivy League schools.