Located in the heart of Jakarta's central business district, the luxury Four Seasons hotel has undergone a major refurbishment and redevelopment with the integration of two new towers into the property. A 55 storey, 244m high residential tower, known as Four Season Residences, and a 30 storey, 132m high commercial tower will deliver world class hotel and residential facilities and provide an iconic landmark headquarters facility for the Rajawali Group.
Ramboll were appointed by PT Rajawali Group to provide multidisciplinary engineering services for the redevelopment of the Four Seasons mixed use project, up to 50% design development stage. Ramboll’s expertise across the high-rise, residential, commercial and hotel markets and our local and technical experience allowed us to quickly identify the most appropriate solutions for each element. Ramboll provided building services (MEP), structural and geotechnical engineering services and other specialist services including Vertical Transport and Fire.
Four Seasons Residences
The 55 storey Four Seasons Residences is a branded Four Seasons product and sets a new high standard of luxury living in Jakarta. The upper floors home high specification apartments and amenities including 3 bedrooms, sky-villas and sky palaces.
The structural design proposal of the Four Seasons Residences comprised of a reinforced concrete band beam frame, allowing the reduction of the central core while freeing up the key corner views of the apartments. Ramboll’s proposed building services design adopted a decentralised approach, placing a portion of the plant local to each apartment, this approach maximises the efficiency of the floor plate and is common to the Jakarta market.
Four Seasons Hotel
The design proposals of the extensive refurbishment to the existing hotel was based on a “minimal intervention” engineering approach, aimed to minimise the need for costly structural and services retrofits and maximise the value of the overall refurbishment.
The refurbishment plans include construction of a new five level basement which covers the majority of the 2.3 hectare site. The proposed basement footprint extends beneath both the new towers and the area between them and will connect directly to the existing Four Seasons Hotel basement, resulting in the demolition of the existing Presidential and northern wings and basement.
Rajawali Headquarters Office
Located in the 30 storey commercial tower, the Rajawali Headquarters will be one of the focal points for the Four Seasons mixed-use development and for the city of Jakarta. Located at the corner of the site, the majority of the development is commercial office space, with associated conference facilities, medical centre and retail located on the lower floors. The office incorporates an atrium/garden which runs up the West face of the building and provides an amenity space for the office as well as acting to improve the energy performance of the building.
To achieve Rajawali’s requirement for the office building to achieve a GREENMARK ‘Gold+’ Award, Ramboll’s building services design focussed on low energy demand including the use of technologies to reduce energy consumption and the buildings annual carbon dioxide impact on the environment.
Geotechnical services
Indonesia is in one of the world’s most seismically active regions, and as such is a challenging location for the design of tall buildings. Further complexity is added to the project by the confined site, the need to integrate with existing buildings, the exceptionally high standards of the client and Jakarta’s vulnerability to flooding.
Ramboll’s geotechnical site investigation consisted of nine rotary core boreholes to depths of up to 120m below existing ground level and provided access for in-situ standard penetration tests (SPTs) and pressuremeter tests to derive soil parameters, seismic downhole tests and a pumping well test. Laboratory testing was undertaken on samples obtained from the boreholes which established that the geological stratigraphy by each borehole was highly variable with layers of clays, silts, sands and gravels encountered at different depths and thicknesses. This variable stratigraphy was fully considered in Ramboll’s design proposal.
