When you publish your site, choose the option to publish to your custom domain. After you’ve done that, you’ll need to let your domain registrar know you want your URL to go to your Houzz site.
You’ll do this by logging in to your account at your domain host. Look for the Domain Manager or DNS Manager and find where you change your A record or A Host. (On Go Daddy, you'll do this in the Zone File Editor.)
Your A Record should point to the IP Address: 18.104.22.168
For reliability, create a second A Record to point to: 22.214.171.124
Then create a CNAME record for www.yourdomain.com to point to yourdomain.com. This CNAME record will make sure that www.yourdomain.com works as well as yourdomain.com and is required for Site Designer to function properly.
You do not need to change the nameserver.
The changes generally take several minutes to appear, but it could take up to 24-36 hours for your site to appear at your domain. Your site will be available after just a couple minutes at yourusername.houzz.com.
Note that if you did not choose the option to publish to your own URL when you first published your site, you can update this in Site Designer. Under Site Options, choose Change My Website Address and select Use my Domain. Then enter your address.
To learn more about changing your A record, visit your domain registrar (some links are below), or contact the company with whom you registered your domain for help.