Way to make reasonably accurate visual measurements

measuring

I'm planning to put up some holiday lights around the eaves of my home. The house is basically Tudoresque with multiple pitches. In order to make the measurements I would like to avoid climbing on a ladder with a tape measure.

Is there a way to make reasonably accurate visual measurements while standing on the ground? Or perhaps a method for measuring using photos?

Reasonably accurate would mean that a small overestimation would be ok, but an underestimation not so much.

Best Answer

For a quick and dirty estimate, I'd try the following:

  1. Take a camera and tripod as far away from the front of the house as you can get.
  2. Level the tripod and camera.
  3. Take a picture of the full face of the house, zoomed in as much as possible.
  4. Verify your scale:
    1. Measure a few points on the house (windows are good, you can measure the picture and the inside of the window) on either side and different floors.
    2. Make sure the scale of the picture at those points is consistent.
    3. Note: they're not all going to be the same. Use the least favorable scale for your estimates.
  5. Assuming the scale is reasonably consistent, measure things on the picture and multiply by the scale.
  6. Add 10% (standard practice).

This works because you specifically wanted to overestimate rather than underestimate. It will be more accurate the further you can get from the house for the picture. I would never recommend this for construction work; but it should be good for holiday lights.