As a manager in a workplace where working from home has not been part of the culture, but the work itself can be done remotely (and HR has a neutral stance, leaving it to managers/units to decide), the main problem my colleagues and I face is that granting this request for one employee means granting it for others who may be more junior (i.e. We have not been able to fully assess their effectiveness/abilities/strengths and otherwise yet), or who we are less confident would work well at home. We are now testing out a program where folks with good performance reviews who have worked with us for more than 1 year can request a 3-month trial period working from home starting 1-day per week and working up to 50% of the time from home after 6 months if all goes well. We will revisit the whole program after 18 months. So far so good!!

Good luck!