How could I maintain a flex agreement when my boss moves on?

Wow - lots of great answers... putting a few things together, I'd offer:

• Determine the expectations of the new position before signing on. Any promotion is a change in expectations, but the most profound is usually the one from individual contributor to manager. At that point, you become much more a representative of the organization and its values than you were before, and that is bound to come with expectation changes. A big question is - does the organization espouse a work-from-home tolerant philosophy? By creating a supervisor with this work-agreement, they are saying to everyone else "this is OK", and the boss may or may not be ready to do that.

• Find win conditions to staying at home - for example is it possible that you can move all your "sit alone and think" work to your day at home, which may allow you to minimize disruptions - often I have suceeded at diverging from my boss' "norm" by highlighting how he's getting more bang for the buck from me doing things differently.

• Be sure that even at home your communication channels are open - if you are hard to reach or perceived as unresponsive, there will be more pushback, as a supervisor must be both easy to reach and responsive.

• Be aware and engaged in talking through the bosses perceptions of how others in the team may react. The boss may not be worried about you, per se, but another person on your team. In which case, you and he may be able to talk through these team issues and find resolutions that don't involve you giving up your work/life balance.

This also gets to a matter involving negotiations. If your position is changing, often the expectations will change with it, even if the supervisor wasn't also changing. Also, engage the supervision in a discussion about why he was initially concerned about when you work at home. Dig deep, ask questions, and don't be defensive in case the answers you start to get back aren't what you want/expect. You'll often find that these kinds of things come down to various ways that people approach work, and how they approach supervision of others.

To some extent, this will come down to the new supervisor's management style, and there may not be a ton that you can do about it - this may be the "new way" that things will operate. On the other hand, you might find that your questions lead to the underlying issues (the supervisor doesn't know how to measure productivity/effort unless they can physically see you, or maybe they feel communication is more effective in person, etc.) which will tell you what you'll need to do in order to satisfy the underlying concerns and potential fears.

Clearly, if you've done a good job, and are in the running for this promotion, then you're capable. With any negotiation, you're spending a certain amount of political capital (whether or not you actively engage in politics) on trying to get what you want, so just be aware of that. Maybe the tradeoff is worth it, maybe it isn't.

The promotion is a new role with new terms and conditions. You need to discuss with your new boss whether it's practicable for you to be out of the office every other Friday.

You can't assume that your current arrangement will carry over.

If you don't take the promotion you should be able to keep the current arrangement - your contract hasn't changed just because your boss has, and you have it in writing. Well assuming that your company treats e-mails as equivalent to letters and someone else (preferably in HR) was copied into the e-mail.

That's pretty typical for managerial or supervisor positions. It's not as big of a deal for normal developers or even lead positions, but once there's an HR component involved (you do reviews, hiring / firing decisions, etc), you're going to lose a lot of flexibility from your schedule (outside of normal PTO type situations). At least, that's the status quo I've seen in the market over the past decade or so.

Remember that in a work-at-home situation, the onus is on you to demonstrate value. One technique that some of my co-workers use is to send an email at the beginning of the day, describing their plan for the day, and at the end of the day, outlining what they accomplished.

Err on the side of overcommunicating when you're working at home. Give them no reason at all to be suspicious.