A report which goes before the Welsh Ambulance Services Trust's board says many of its stations are in 'poor condition' and need basic repair.
Wayne Evans said the facilities were not adequate for the staff
Building work is currently being carried out on stations and around 19 need to be brought up to basic health and safety standards.
The ambulance service is also considering cutting down from 90 permanent stations to 17 larger depots.
The modernisation plan has been completed after wide consultation.
Building work is underway at Llanelli station as the station was built originally with 10 staff in mind but now there are 28 workers located there.
"There's a gents' toilet and shower room and a ladies' toilet but with 28 staff it's not adequate," said location manager Wayne Evans.
"We've got 28 members of staff on the emergency side and patient transport services side - they need the facilities.
"The quiet room had five people working there at one time, which was not fit for purpose.
"We're currently undergoing a modernisation plan, very much focused on patients but obviously we have staff welfare issues as well in mind."
But in the long term, the ambulance service is considering cutting down on the smaller stations, keeping larger stations which would be supported by other response points around the country.
The response points would be shared with other parts of the health and emergency services.
Work is underway at Llanelli station to modernise the facilities
In August the new head of the embattled ambulance service Alan Murray, vowed to turn things around from what had been described by predecessors as a "crisis". He said £140m needed to be invested.
The ambulance service has been the subject of two major reports in recent months, one by Auditor General Jeremy Coleman, and the other by Healthcare Inspectorate Wales.
The report issued by the auditor general in 2006 referred to serious problems which had continued at the ambulance trust for several years.
It pointed to a longstanding lack of direction as well as weaknesses in leadership at board level.
Inflexible shift patterns for ambulance crews had led to the service not matching the peak demands on ambulances and patient-care services, even though the overall staff and revenue resources appeared adequate.
It also stated that management failures had left the service with an inadequate fleet of ambulances, partly because it had a fleet of 46 vehicles which were not fully fit for purpose.