Allowing googlebot access to site during 3 week down time

[jovato]

I have a site that is taking in some substantial traffic, but we will be doing some large changes internally to the content that will take three weeks. During this time we will be using temp redirects for all users to a page that will explain what is going on, and when we will have the site back.

During this time can I allow the googlebot to keep accessing the site even though I am sending all other users to the status page? Is this against their terms of service?

I appreciate any advice.

[deadsea]

This is clearly "cloaking". You will be showing Googlebot different pages from users. Clearly against the Google webmaster guidelines.

On the other hand, a three week downtime will be noticed by Googlebot. You will lose many rankings and take a long term hit of 50 to 70% of your search engine referrals.

[dstiles]

I'm currently going through a directory of sites looking for those that have "expired". Many of the sites I've killed have "down for rebuild" notices. Some of these look like they've been there for some time and others are obviously new owners.

My point: keep a live site with expected pages at all times otherwise someone linking to you is liable to kill your backlink. As will all SEs, not just google.