Singapore withholds the occupation permit until the authority has cleared the planting

Trends · Jul 2026 · 5 min read · 29 sources

Singapore makes developers plant through the occupation permit. Since April 2009, its Urban Redevelopment Authority has withheld clearance from a development under its planting rule LUSH until the planting is finished, and without that clearance the building gets no occupation permit. In 2019, the building scientist Ziyou Huang and colleagues found that upkeep made up most of the 30-year cost of vertical greenery in eight Singapore projects.

Written by

Christian Huser
neuecon partners

Before that permit, the owner earns nothing from the building.

Planting spilling over the floors of a building in Singapore, traffic on the street below.

Singapore's population and green cover grew over the same two decades

In June 2026, I analysed 29 sources for a report for The Built Review on how Singapore makes developers plant. They include the planning circulars, cost data from Singapore and the only independent evaluation of the Bosco Verticale in Milan that I found.

On 11 May 1967, two years after independence, the prime minister Lee Kuan Yew announced the Garden City programme. In 2013, the landscape researcher Puay Yok Tan and colleagues measured Singapore's green cover on satellite images: 35.7% of the island in 1986 and 46.5% in 2007. The Singapore Department of Statistics put the total population at 2.73 million in 1986 and 4.59 million in 2007. One of the authors of the 2013 paper is a researcher at the National Parks Board, so the agency documents part of its own record. The series ends in 2007, two years before the Urban Redevelopment Authority introduced its planting rule.

The authority checks the planting before the building opens

The rule is called LUSH, Landscaping for Urban Spaces and High-Rises. In 2014, the authority extended it beyond the strategic areas to flats and condominiums and to commercial projects, and in 2017 it tightened the rules. In the designated strategic areas, a development must provide outdoor areas for planting and plazas at least equal to 100% of its site area, or 70% where the height of buildings is restricted. At least 40% of these areas must be permanent planting. Green walls and thin green roofs count for at most 10% of the required area. Potted plants do not count.

The circulars set no fine. The authority inspects the finished areas, and until it has cleared them, the Commissioner of Building Control does not issue the Temporary Occupation Permit. Before that permit, the owner earns nothing from the building. After occupation, the owner may reduce these areas only with the authority's approval. By late 2017, the authority counted more than 130 hectares of greenery delivered through the programme.

Berlin, Seattle and England also require planting in planning law

Berlin has used its Biotope Area Factor, a minimum share of a plot that must support plants or absorb water, since 1994, binding in areas with a legally adopted plan for open space. Seattle has set minimum scores for planting in designated zones since 2007. Since February 2024, England has required most new developments to deliver a 10% gain in measured habitat value over the value before development, and to secure the gain for 30 years, under the Environment Act 2021. In Denver, voters passed a green-roof ordinance in 2017. A city task force found that many existing buildings could not carry the weight of a green roof. For large single-storey retail buildings, the required roof cover was particularly burdensome. In October 2018, the city council replaced the ordinance with a Green Building Policy that offers other ways to comply.

The claims for a green tower and a green hospital go further than the data

The practice of the architect Stefano Boeri credits the Bosco Verticale in Milan, completed in 2014, with absorbing 25 to 30 tonnes of carbon dioxide a year and with lowering indoor temperatures by 2 to 3 °C. These figures come from the architects' own project material, and I found no independent peer-reviewed study that supports them.

The trees did little for the building's energy use in the one independent evaluation. In 2015, the architecture researcher Elena Giacomello and the agronomist Massimo Valagussa modelled its sixth floor in three versions of the façade for the Council on Tall Buildings and Urban Habitat, with a research grant from the engineering firm Arup. With terraces and trees, the model put the electricity for heating and cooling at 12.7 kWh per square metre per year, against 13.7 for a plain façade. Terraces without trees also came to 12.7, because the deep concrete terraces gave the shade. Giacomello and Valagussa call the plants' own contribution to the saving "somewhat negligible". Terraces and trees together also blocked the low winter sun and raised the modelled annual energy need for space heating by 37.3% over the plain façade. Terraces alone raised it by 10.6%. The study used data from before occupation and measured neither the absorption of carbon dioxide nor the carbon emitted in construction.

The Khoo Teck Puat Hospital opened in 2010 and received the first Stephen R. Kellert Biophilic Design Award of the International Living Future Institute in 2017. The award material and commentary from people involved in the project say that the hospital "consistently out-performs" all others in the patient satisfaction survey of the Ministry of Health. In 2012, the ministry ranked it first among public hospitals, with 83% of patients rating their overall satisfaction as excellent or good. In 2013, it came second, behind Alexandra Hospital. In 2014, it ranked first again, with 86%, in a year when Alexandra Hospital did not take part. The ministry has published no results by hospital since 2015.

Vertical greenery costs most after it is installed

Huang and colleagues calculated the cost of vertical greenery, green walls and other plant systems on façades, in eight Singapore projects over 30 years. Operation and maintenance made up 73.7 to 83.9% of the total, and replacing plants was the largest item. Over 30 years, the dearest support system cost 5.5 times as much as the cheapest. Only the simple support system saved enough energy to repay its cost within 30 years.

One Singapore study measured the price of a green label

In 2012, the real estate economist Yongheng Deng and colleagues analysed about 37,000 housing transactions in Singapore. Homes certified under Green Mark, Singapore's green building label, sold at prices about 4% higher than homes without the label.

I think the missing number is the cost per project

I think the occupation permit gives LUSH its force, and for vertical greenery I think upkeep decides what the rule costs a developer over the years of use. I found no figure for what LUSH costs a single project, from the authority, from the Building and Construction Authority or from a university. Nor did I find a study that measured what greenery a developer was obliged to plant adds to the price of a home.

Sources

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