It depends on your goals and it depends on you (do you have discipline?) and the company you work for. If you're trying to climb the corporate ladder, then yes

It depends on your goals and it depends on you (do you have discipline?) and the company you work for. If you're trying to climb the corporate ladder, then yes this will slow you down if you're working from home 3-5 days a week. If you want something else like work life balance or more time to work on your side projects by saving time (no more commute, less time spent socializing with coworkers, ...), then it's a no brainer. IANAL but I would advise against working on your side projects during work hours.