I know this is about 30 days old but with no response to it I think it deserves an answer. The only issue with that is that depending on how you are coding your site, you can't be 100% sure it will work on the hosting platform you end up hosting on. Every host configures their servers differently and use different security measures. I always think it's best to test the site on the actual hosting account to make sure everything will work without issue when you go live.
That being said, the basic design and layout is a good idea to have ready. But when it's time to code the site, you should have it on its hosting space.