These range from the need to reconfigure work areas to maintain safe distancing to the mental readjustment workers have to make to pivot back to being on-site.
Introducing staggered hours or shifts may also create problems, said human resource executives and experts.
Leong Chee Tung, chief executive and co-founder of human resource technology firm EngageRocket, said it might be counterproductive to make staff work half the day at home, and half in the office.
"Task switching has a significant effect on attention and productivity, making it likely that being subjected to such a split schedule will cause a lot more time spent mentally wandering than focused on work," he said.
"It is much better to have either the full day working in the office, or working from home."
Mayank Parekh, chief executive of the Institute for Human Resource Professionals, said some companies could roster staff to work on alternate days or weeks in the office.
"There is a slight preference for alternate weeks as if there's any Covid-19 case in that one week, the next week, all staff can work off-site and won't cross-contaminate," he added.
Associate Professor Trevor Yu of Nanyang Technological University's business school said: "The challenge with staggering hours and shifts is to find a fair and equal system that takes into account business requirements and the needs of employees."
He said it is critical to involve staff in scheduling duty hours to settle on an arrangement that satisfies employees and employers.
Associate Professor Song Zhaoli from the National University of Singapore Business School said irregular office working times can become a major source of stress.
"Before Covid-19, most workers had regular working hours in a week. People knew when to go to work and when to come back home. Such certainty makes it easy to coordinate family time as well," he said.
"Now, the new work scheme will lead to uncertainties in terms of which days and what time to go to the office and when to leave the office. This will likely lead to stress."
FastJobs general manager Lim Huishan said that it may also be necessary to implement staggered lunchtimes if the volume of people returning to the office is high, especially since eateries also have reduced capacities due to safe distancing requirements.
Besides the complexities brought on by rostering staff, offices might also have to move towards different spatial configurations to ensure safe distancing, experts said.
Prof Song said: "In the future, co-working spaces are likely to be preferred, given their flexibility to adjust and change.
"Social distancing measures as well as a reduced workforce working from the office will likely lead to the underutilisation of workspaces, which can be a significant cost.
"How to make future workspaces more nimble and flexible will be major considerations in future office design."
Unispace managing director for Asia Toby Rakison said office spaces also need to shift towards fostering collaboration rather than individual work, which can be done at home.
"Fundamentally, when it comes to office design, the focus needs to be less on the individual desk and more on creating conducive spaces."
For instance, insurer Great Eastern recognised even before the pandemic that flexi-work arrangements and moving away from standard rows of desks were the way to go.
One of its office floors was redesigned to include facilities for videoconferencing, workspaces that can be easily converted for different purposes, and open-concept collaboration areas.
"We must continue to keep our minds open to new ways of working. The pandemic has accelerated this for many industries," said Mr James Lee, the company's managing director of group human capital.
The experts reckon that companies and staff are unlikely to rush back to the office, arguing that the challenges of returning to workplaces may be alleviated if people are eased in gradually, instead of all at once.
A Straits Times poll on the newspaper's social media pages and Telegram found that about 62 per cent of more than 7,100 respondents did not welcome the move to return to the workplace from this week.
Mr Leong said: "Some employers are very eager to have their employees back in office to be able to 'manage by face time', and therefore rush the transition back to work.
"This would be a mistake, and would incur productivity cost. Easing staff back to the office gradually will allow workflows to adapt and maintain high levels of productivity instead of a big-bang approach that is more likely to cause confusion."
Adecco Singapore country manager Betul Genc said: "Despite the announcement by the multi-ministry task force, with telecommuting still the main mode of work and with strict regulations in place, we do not foresee many companies getting their employees to head back to work."
Prof Yu said: "Managers should be especially attentive to the psychological and socioemotional well-being of their subordinates during this time.
"Regular check-ins and getting constant feedback on how the adjustment is going will be helpful."
The 20 staff at non-profit organisation Industrial and Services Cooperative Society (Iscos) will stick to their split-work arrangement, with only the counter service and operations workers required to be on-site to tend to clients.
The rest will continue working from home unless they have to go to the office to access the client management system or shared drives.
"Although more can return to the office, we don't have to max it out for the sake of doing so. We foresee ourselves staying in split-team arrangements for a long time - until phase three, or when a vaccine is found," said Iscos executive director Doris Ng.
But health-tech start-up Plano, which specialises in myopia management, is looking at more staff returning to the office to restore cross-team discussions and revitalise the company's culture of camaraderie.
"The new workplace conditions were a relief for many of my staff, who have bubbly personalities and feed off one another's ideas.
"Sometimes, culture rebuilding is more important than keeping your company alive," said founding managing director Mohamed Dirani.
fter the announcement that more employees can return to the workplace, Plano's executive team set guidelines to allow about 10 staff from various sections to go to the office from this week at staggered times. The schedules will take into account each worker's inputs and preferences.
Dr Dirani also acknowledged that a sudden shift in work scheduling after working from home for months can be stressful.
"Employees may have developed habits over the last six months, and we need to be considerate and be accommodating to those who need time to transition." - The Straits Times/Asian News Network