Such small-scale home-based businesses do not require owners to notify the authorities. They just need to adhere to the criteria listed by the HDB for its flats and the Urban Redevelopment Authority for private housing.
Experts said that home-based businesses, although not suitable for every industry, are becoming more popular.
Mr Paul Heng, managing director of NeXT Career Consulting Group, said it is because the costs of such a business can be managed more effectively.
■ Activities must not cause any nuisance, for example, noise, smoke, smell, chemical/liquid waste, dust or litter
■ No employees allowed
■ Flat is still used for residential purposes
■ No excessive human or vehicular traffic