My husband and I have been renovating our house (HGTV/DIYnetwork style, sadly without the help of Chip and Jo from Fixer Upper or Yard Crashers) and I realized it was the perfect opportunity for some real world geometry. The inside is almost completely done with a new kitchen and new flooring, so next we will move on to the outside. I put together an assignment for my students to help us calculate how much our renovations would cost using area and perimeter of polygons and presented them the idea of helping us be sure our calculations were correct as well as deciding a best option for an additional dog run area we have been designing. My kids totally bought into it the relevance of this assignment and the meaning behind it as I could tell they truly wanted to help us make our house the best it could be. After class, I even had a student tell me they were building a new house and asked if we could make a math problem out of her house plans!
Side note: Our patio and deck plans are not actually a rhombus and a perfect parallelogram, but it made for more challenging and relevant math. Everything else was real data, decisions we are trying to make, and plans we want to do!