At this point June 2016, Houzz.com has disabled any third-party site, SampleBoard and Pinterest alike, from clipping images from their website. You can read more unhappy designers here, voicing how frustrated they are.
The only way to get around this issue, is to screenshot the webpage on Houzz, save it to your desktop and upload the screenshot image to your SampleBoard account the old-school way.
Believe me, I am just as disappointed as you : (
// THE BELOW IS NO LONGER WORKING //
STEP 1: Browse images within Houzz and once you have found your desired image click the >> button situated at the bottom right-hand corner of the image. Refer to the screenshot below.
STEP 2: Your selected image will enlarge as per the this screenshot
STEP 3: Refer to your Bookmark tool and click "save to SampleBoard". The green horizontal popup will open as per this screenshot.
STEP 4: Click on the image you want to add to your SampleBoard library, select your library folder and add additional details if you want.
STEP 5: Go back to your SampleBoard Library. You will find your Houzz image imported and saved in your chosen library. It will appear last in the library.