PTTEP, Thailand's national petroleum exploration company, occupies eighteen floors in the ENCO building in Bangkok, consolidating functions previously spread across a number of sites. The competition-winning design by HASSELL creates an open plan workplace, configured around a new internal stairway that provides a physical and visual link between all levels of the 45,000 square metre tenancy.Breakout and hub spaces are situated adjacent to stair landings to encourage staff interaction. Utility rooms are located around the central core ensuring work space areas are positioned with close proximity to natural light. This open plan approach is a significant change for PTTEP and has strengthened the culture of the company.The interior colour scheme was inspired by the luminous gas flame associated with oil exploration and production with the gradation of colour in the flame helping to create a unique identity across the floors.The introduction of a dedicated client floor, and a separate executive suite accommodating all management facilities, enabled PTTEP to maximise the general workplace facilities. Two landscaped external roof decks provide additional space for staff recreation and other corporate activities. Established trees and vertical wall climbers create a lush and green environment to complement the building's glazed truss parapet.