Sensor-controlled smart lighting saves energy but costs more to install than normal lighting. Greenery lowers a building's temperature and hence the need for cooling - but also requires water.
To help weigh such trade-offs, the Housing Board (HDB) has a new computer modelling tool.
It is part of the HDB's smart planning efforts, which include designing towns for optimal wind flow and shade.
The Complex Systems Modelling (CSM) tool helps the HDB simulate the effects of a given feature - like solar panels or rainwater harvesting - on variables such as energy consumption, costs or greenhouse gas emissions.
It can therefore be used to decide between different options.
"This is particularly useful for our town planners because they cannot afford experimentation with actual developments in land- scarce Singapore," said the HDB in a factsheet released to the media.
For instance, at Yuhua estate in Jurong, the CSM tool was used to investigate sensor-controlled smart lighting versus low-energy LED lighting. Such simulations help planners find the best solutions without physically testing the options.
The CSM tool was developed by the HDB, Electricite de France and Veolia Environnement Recherche et Innovation. The first prototype was unveiled at last year's World Cities Summit in Singapore.
It has since been tested in the planning stages of the Punggol Northshore district, and will eventually be tested at the town level.
Besides new towns, CSM may also be used to study the feasibility of the HDB Greenprint programme, which brings green initiatives to older towns.
Another of the HDB's smart planning tools allows planners to test how blocks of flats affect the wind flow and shade in an estate.
With the Urban Environmental Modelling (UEM) tool, planners can tweak the shape and position of flats, and see the results in a computer simulation.
It can also be used to identify hot or shady spots within a town.
Greenery can be planted in hot areas to lower the temperature; amenities such as playgrounds can be located in areas with more shade, and housing units can be angled to reduce heat gain from sunlight.
Treelodge @ Punggol, completed in 2010, was the first HDB project planned with the help of wind flow simulation.
The UEM tool was later used to help plan new precincts in Punggol town, and will be applied to new housing areas such as Bidadari and Tampines North.
The tool helps planners "determine how best our new flats can be designed and sited to provide maximum thermal comfort and a more conducive living environment for our residents", said the HDB.