Oasis Hotel Downtown and its sustainable aspects according to green building rating system. The BCA Green Mark awards recognises developers, building owners and individuals who have made outstanding achievements in environmental sustainability in the built environment.

1. OASIA HOTEL
DOWNTOWN
A Living Building
Kritika Patel
AR18008
B. Architecture 5th sem.

2. 2|AR18008|Oasia Hotel Downtown
Building name: Oasia Hotel Downtown, Singapore
Location: 100 Peck Seah Street, Singapore
Architects: WOHA
Clients: Far East SOHO Private Ltd.
Design Inception: 01 February 2011
Start of Construction: 01 February 2012
Completed year: April, 2016
Gross Floor Area: 19,416 m2
Plot Area: 2,311.4 m2
Height: 199.080 m2 including 42.9 m high roof crown
Number of Floors: 27 Floors
Number of Offices: 100 Offices
Number of hotel rooms: 314 Hotel Guestrooms. (224 Hotel Typical, 88 Hotel
Club, 2 Suites)
Sustainability Certificate: BCA Green Mark Certified by Singapore Green Building
Council
Photographs: Patrick Bingham-Hall, K. Kopter, Courtesy Of WOHA
References:
1. https://www.bca.gov.sg/Professionals/IQUAS/IQUAS/DynamicPages/ass
mtBenchmark.aspx
2. https://www1.bca.gov.sg/buildsg/quality/conquas
3. https://www.bca.gov.sg/GreenMark/others/BCA_Green_Mark_Hotels.pdf
4. https://www.bca.gov.sg/GreenMark/others/GM_ENRB_2017_full_criteria.
pdf
5. https://worldlandscapearchitect.com/oasia-downtown-hotel-a-singapore-
building-wrapped-in-a-living-cloak/#.X2nJGfYzbcu
6. https://global.ctbuh.org/resources/papers/download/3790-oasia-hotel-
downtown-singapore-a-tall-prototype-for-the-tropics.pdf
7. https://www.archdaily.com/800878/oasia-hotel-downtown-woha
8. https://pda.designsingapore.org/presidents-design-award/award-
recipients/2018/oasia-hotel-downtown
Awards:
1. Best Tall Building Worldwide by the Council on Tall Buildings and
Urban Habitat (CTBUH)
2. The Design of the Year 2018 award conferred by The President’s
Design Award, Singapore
3. Singapore Good Design Mark Platinum Award 2017 from Design
Business Chamber, Singapore
4. Building Of The Year 2017 winner and Design Award 2017 winner for
Commercial Projects by Singapore Institute of Architects (SIA)
5. Green Good Design Award from the European Centre for Architecture
Art Design & Urban Studies & the Chicago Athenaeum

3. 3|AR18008|Oasia Hotel Downtown
Information on Construction Quality
Project ID: 20130900
Project Name: Oasia Hotel Downtown
Structure Score: 100
Architecture Score: 94.3
Mechanical & electrical (M&E) Score: 99.8
Construction Quality Assessment System (CONQUAS): 96.8
Period From: 2016-2020
Information on Sustainability Certificate
Green Mark Rating: Green Mark
Certified
Green Mark Score: 50 to <75
To dovetail the criteria with the
sustainable outcomes of GM ENRB:
2017, the criteria is re-structured into 5
sections with 11 pre-requisite
requirements and 42 criteria.
Internal Finishes
Element
Project
Defect %
Industry
Maximum
Defect %
Industry
Minimum
Defect %
Project Rank Average
Defect %
Walls Defect % 5.00 51.50 10.48 48/48 13.79
Ceiling Defect % 7.50 34.00 2.67 2/48 11.60
Floor Defect % 15.50 64.35 9.05 6/48 13.37
Component Defect % 12.00 34.00 0 31/48 13.37
Door Defect % 25.83 51.55 0 28/48 3.52
Windows Defect % 20.00 51.54 0 28/48 5.19
Sustainable
Management
, 35
Building
Energy
Performance,
40
Resource
Stewardship
, 30
Smart &
Health
Building , 40
Advance
Green Effort
, 20
Figure 1 Comparison between
defect percent
Figure 2 BCA Green Mark Rating Criteria

4. 4|AR18008|Oasia Hotel Downtown
OASIA HOTEL DOWNTOWN, SINGAPORE
ABSTRACT
Oasia Hotel Downtown is a prototype of land use
intensification for the urban tropics. Unlike the sleek
and sealed skyscrapers that evolved in the temperate
west, this tropical “living tower” is designed to soften
the hardness of the city and to reintroduce biodiversity
into the urban jungle.
INTRODUCTION
Located in the heart of Singapore’s Central Business
District and overlooking the historic Tanjong Pagar
district, Oasia Hotel Downtown constructed by WOHA
architects is distinctive in its expression, forming a
spectacle of architectural design and engineering.
Surrounded by the high-rises, the 191 m tower with
19,416 m2 built-up area on the 2500 m2 plot of land rises
up from the tree-lined streets as a verdant tower of
green, presenting an alternative imagery against the
concrete and glass cityscape. It offers a vision of a new
typology for the tropical skyscraper- one that is suited
to the local climate, with internal breezeway atria,
multiple sheltered terraces, sky gardens and vertical
greening. Opened in April 2016, the tower has quickly
become beacon of nature and an oasis in city’s dense
surroundings.
DESIGN FEATURES
Responding to the client’s requirements for distinct
offices, hotel and club rooms, the tower landscaped
sky terraces, inserted in naturally ventilated
breezeway atria between room blocks. These
provide guests and occupants generous amenity
spaces throughout the high-rise with dynamic
internal views that frame, soften and distance the
surrounding dense urban fabric. It has a barrel
shaped roof, containing climbing vines. The intent
of the design is to mimic s with a green stem once
the creepers on the building’s façade are fully-grown. No mechanical ventilation is needed for
the hotel rooms or offices because of the open-sided sky gardens. Water for irrigation of the
plant life comes from rainfall.
Figure 3. Oasia Hotel Downtown, Singapore
Figure 4. View of rooftop pool deck and enclosure from top

5. 5|AR18008|Oasia Hotel Downtown
Within Oasia are rooms for the Hotel, the Hotel Club
and private strata SOHO (small office home office) units
which results in horizontal stratification of the tower
into four sections. With this zoned layering, levels 6 to
11 are designated to individual SOHO owners; the Hotel
occupies levels 12 to 20 and levels 21 to 26 belong to the
Hotel Club rooms and activities. Level 27 houses
common recreational activities for both Hotel and Club
guests. The site is tiny, and the building footprint
occupies it entirely, minus the mandatory planting
buffers. With the tower in stratum – each for a different
section of accommodation – the surface area of the site is
multiplied four times, as the four sky gardens at levels 6,
12, 21, 27 become as “new ground” planes overlooked
by either apartments or hotel rooms, one sheltered by
the next terrace above, until the last plane is open to sky
at level 27 (Figure 4 & 5).
• Integrating Mixed Uses
The brief called for three distinct components – strata-
titled offices, standard hotel guest rooms and club guest
rooms, within a single tower on a tight 47 x 47 m2 site.
Although housed within a single building, the office,
hotel & club components needed to be separated from
each other for security purpose as they serve to different
user groups.
The conventional solution would have been to deploy a
central core with an apron of exterior-facing offices and
guest rooms. This arrangement inevitably puts pressure
on the separation of vertical circulation paths to serve
the office, hotel/club, hotel back-of house, and
services. Instead, to free up the ground plane, the
design elevates the hotel back-of house to the 3rd
story and the car park to the 4th and 5th stories. In
doing so, much of the ground is given to the drop-off,
arrival lobby, all-day-dining restaurant, bar, and
concierge so as to activate the public realm along
three of the four frontages.
The design resolved the programmatic segregation
issue, simply by splitting the cores, sending the
vertical circulation and services to the four corners
and stacking the three programs in separate L-shaped
blocks. The elbow of each block is flipped to the
opposite corners to orientate to different parts of the
city. Each block is served vertically at the corners opening up the breezeway atrium at the
Figure 5. Oasia Hotel Downtown - section
Figure 6. The sky terrace at the 6th storey, provides
a porous urban living room for the office floors
“The building does not just
look like a tree, it performs
like one too”

6. 6|AR18008|Oasia Hotel Downtown
centre. Sky terraces, equivalent in area to the building
footprint, are inserted between each stack, offering
generous landscaped and amenity decks (Figure 5).
• Sky Terraces
With the cores located in the corners, terraces allow a
unique 360-degree view through gardens to the city,
which would not have been possible with a typical
center-core tower. Despite the limited footprint, public
areas the size of the ground plane are multiplied four
times throughout the tower. The planting that surrounds
and stretches all the way to the edge of each sky terrace
reinforces the impression of the ground.
A dedicated core next to the drop-off on the ground level
brings the occupants directly up to the sky terrace on the
6th story and the offices at the 7th through 11th storey. The
sky terrace is an open-plan living room shared by the
offices with casual and formal meeting spaces, lounge,
gym, and lap pool (Figure 6).
Another dedicated core brings the guests to the sky
terraces at the 12th and 21st stories respectively. Guests
check in at these two sky terraces instead of at the ground
level. Here guests navigate horizontally across the length of
the sky terrace to another set of lifts to transfer to the hotel and
club guest rooms located on the 13th-20th and 22nd-26th stories
respectively. This horizontal transfer within landscaped sky
terraces gives the guests a unique garden experience in the
dense CBD.
The sky terrace at the 12th story is a garden veranda, with an
activity courtyard bordered by a patio with a pergola, lounge
seating and a function room, and surrounded by greenery
(Figure 7).
The sky terrace at the 21st story is designed as an urban resort
in the city, with a stepping deck connecting an infinity pool,
executive lounge, open hall, water gardens, and planter beds
(Figure 8).
The roof terrace at the 27th story is anchored by a specialty
restaurant, flanked on both sides by sun decks and lap pools
(Figure 9). Mechanical and electrical equipment typically
found at the rooftop is instead fitted along two sides and below
the floor.
Figure 7. The sky terrace at the 12th storey,
serving the hotel, forms an urban veranda
Figure 8. The sky terrace at the 21st storey, serving
the hotel floors & features a large pool
Figure 9. The roof terrace at the 27th storey,
supports sun decks & pools & is
surrounded by a tapering enclosures,
extending the green skin of the tower

7. 7|AR18008|Oasia Hotel Downtown
By dividing the tower into vertical segments, the sky terraces
provides not only multiple elevated grounds for greenery and
amenity, but also create legible human-scale environments in the
sky.
• Breezeway Atria
The L-shaped blocks, set onto a square plan, result in 21 to 35 m
tall breezeway atria at each sky terrace. The say terraces also
serve as huge overhangs, directly shading the terrace below.
Open-sided, the atria a cross-ventilated from all directions, aided
by a natural funneling effect.
Each atrium achieves an approximate 1:1 height to depth ratio,
affording a bright and airy environment with daylight and cross
breezes, coupled with evaporative cooling from water and
shading from greenery. The atria also carve out spaces that offer
dynamic internal garden views, while framing, softening and
screening the surrounding dense urban fabric.
Instead of being enclosed, air-conditioned and artificially-lit
spaces, the atria are comfortable, sheltered volumes with
natural light and fresh air, in contrast to the hermetically
sealed buildings elsewhere the CBD (Figure 10).
• Living Screens
The tower has neither a solid mass nor a full-height curtain
wall. The stacked blocks and terraces are enveloped by 25,000
m2 of expanded aluminum mesh screens. About 1,800
prefabricated fiberglass planters of size 1100(L) x 650(W) x
1050(H) cm3 are located on every story, abutting the screen so
that creeping vines are only required to climb 3-5 m before
overlapping with the nest tier of planters. Over time, the wires
will spread over every surface (Figure 11).
Landscaping is used as the architectural environment finer
and material palette, not as a cosmetic add on. As an envelope,
the greenery and the screen function as filters that proved
shade, reduce heat, dampen noise, cut out glare and dust, and
improve air quality. As a finish, the screen is a composition of
five colors- red, dark red, pale pink, fuchsia, and orange, a
range that mimics the natural color variation in plants as they
shoot, mature, and dies off. The screen will eventually recede
behind greenery and will appear as a background of varying
color accents, like flowers within the vertical foliage. Red color
gives good contrast to the lush greenery and cool blue sky to
allow the building to stand out amongst the dull colored
downtown skyscrapers. This is similar to how warm hues of
Figure 11. Creeper vines, planted in 1,800
fiberglass planters along the building’s
exterior, have grown steadily over less than
2 years, covering several of its surfaces
Figure 12. The tower’s greenery extends
to street level, connecting it with
existing urban & natural habitat
Figure 10. Oasis’s open- sided, cross-
ventilated breezeway atria contrast with the
hermetically sealed towers in the immediate
neighborhood

8. 8|AR18008|Oasia Hotel Downtown
fruits and flowers contrast
against green foliage and earth
in nature.
The color and texture of the
facade change with light and
shade, rainfall, and natural
cycles of plant life. Through
this, the tower becomes a
living artwork of nature.
• Man-Made
Ecosystems
21 species of creepers were
selected and distributed across
the facades, based on their sunlight requirements, rate of
growth, density of coverage, texture and color (Figure 13).
Some species produce colorful flowers that attract birds and
insects at different times of the year. With the facade coming
close to existing roadside trees and landing at ground level the
building extends those existing roadside habitats vertically
(Figure 12). Together with 33 different species of trees and
shrubs planted on the sky terraces, there are a total of 54
species of plants within this living tower. The variety of plants
also provides natural resilience against disease-carrying and
destructive insects.
To ensure the practicality and ease of maintenance of the
greenery, cat ladders and catwalks are incorporated alongside
the planters so that there is safe and direct access, without the
need for ropes maintenance personnel and gondolas (Figure
16). All planters are watered by an automatic irrigation system
to avoid wastage. Like a tree, the tower breathes,
metabolizes & photosynthesizes. It protects and
shelters, creating natural habitats and attracting
biodiversity. And by doing so, it hosts ecosystems as
well as programmatic spaces, allowing nature to co-
exist with buildings.
A PROTOTYPE FOR LIVABILITY
SUSTAINABILITY
With all green and blue surfaces amalgamated, the
tower achieves an unprecedented overall GPR of
1,100%. In other words, it provides 10 times as much
greenery to the plot as was originally on the undeveloped site. It effectively compensates for
the lack of green in 10 additional sites of equivalent area.
Figure 15. Facade consist of columns with
aluminum wire mesh over which vines are growing
Figure 13. The arrangement of 21 species of climbers on the 4 facades of the towers
taking into consideration water demand, amount of sunlight & speed of growth
Figure 14. Creeper vines along the
building’s exterior creating contrast

9. 9|AR18008|Oasia Hotel Downtown
Beyond this, tower demonstrates generosity & good citizenship by
giving back to the city. Within the building, people are surrounded
by nature. Around the building, the vertical green screens and
landscaped sky terraces provide a welcome respite to the built
environment. The tower is a biophilic three-dimensional
environment that heightens the human experience of nature –
within the building interior or as the next- door neighbor, up close
at the urban street level, from afar at the city level – bringing a sense
of beauty and delight to everyday life.
CONCLUSION
It is important to see architecture as more than a collection of
seductive forms & facades and to bring the attention back to
architecture’s capacity to create human-centric environments. Oasia
Hotel Downtown is a striking spectacle, yet is also
environmentally friendly, culturally appropriate and climatic
sustainable. For this project, located at Peck Seah Street on a site
of 2311.4 m2 the landscape architect was responsible for the
green façade of the building, while the sky terraces were a
result of collaborations between the architect, the landscape
architect and the interior architect. For the landscape works the
landscape architect undertook full scope from concept design to
site supervision. It is a prototype that reimagines a tall building
as a responsible, livable and sustainable high-rise environment
that contributes to the city on different levels.
At the building scale, it makes land-use intensification
beneficial, with its high-rise tropical spaces, garden facing
layout and porous living skin. It sets new precedents by
integrating and maximizing vegetation within high-rises. It
demonstrates the possibility of a more balanced coexistence
between city and nature, engaging and benefitting people both
within and outside the building. At the urban scale, it shows
that tall buildings can offer meaningful and
fulfilling urban habitats beyond the ground
plane. It demonstrates that buildings can be
important components in improving the
quality of green open space, community
space and biodiversity in cities. It provides a
template by which private building can
contribute to the common good of the people,
the city and the climate.
Figure 17. The maintenance access
consisting of catwalk alongside the
prefabricated fiberglass planters attached to
aluminum screen
Figure 16. The façade structure
consists of a maintenance catwalk,
fiberglass planters & an expanded
mesh screen
Figure 18. Organic mosaic where nature creates its own pattern as
plant find their equilibrium