Basement Construction for Landed Homes in Singapore: Is It Worth It?

With land prices at a premium and various building limits capping what you can build above ground, basements offer a compelling way to gain additional space. But basement construction in Singapore comes with unique challenges—high water tables, strict regulations, significant costs, and complex engineering. This guide helps you weigh the decision.

Why Consider a Basement?

A basement can be a highly effective way to increase usable space in a landed home without impacting the building’s visible massing above ground. Subject to URA guidelines, fully submerged basements are generally permitted within landed housing developments and, in certain situations, may not be counted as an additional storey.

This creates an opportunity to introduce functional spaces such as entertainment rooms, home theatres, gyms, wine cellars, utility areas, or storage, while maintaining the overall building height and external profile.

However, it is important to note that basement areas are not automatically exempt from Gross Floor Area (GFA) calculations. Enclosed and usable basement spaces may still be counted as GFA unless they meet specific exclusion criteria under URA regulations. As such, basement design should be carefully planned in coordination with prevailing guidelines to optimise both space and compliance.

URA Guidelines for Basements

URA generally defines a basement as a storey with its floor level at least 1 metre below the average ground level adjoining the building. In landed housing, basements are allowed subject to planning controls, including setback requirements and site conditions.

Engineering Challenges in Singapore

High Water Table

In many parts of Singapore, the groundwater table can be relatively shallow—particularly in low-lying areas or near waterways. This presents a key challenge for basement construction, as the structure must effectively function as a watertight “underground box.” Robust waterproofing systems—such as tanking membranes, waterproof concrete, and subsoil drainage—are critical. Any failure in waterproofing can lead to water ingress, dampness, and long-term maintenance issues.

Soil Conditions

Singapore’s subsurface conditions vary significantly by location, ranging from soft marine clay in coastal and reclaimed areas to denser Old Alluvium in the east. Softer soils typically require more complex and costly earth retention and foundation systems during excavation. A detailed soil investigation report, commissioned early in the project, is essential as it determines the appropriate engineering approach and has a direct impact on construction cost and methodology.

Excavation and Earth Retention

Basement excavation in built-up residential areas requires carefully designed earth retention systems (ERSS) to safeguard adjacent structures. Common methods include sheet piling (which may generate noise and vibration), secant or contiguous bored pile walls (generally quieter

but more costly), and soldier pile systems. In Singapore, ERSS must be designed and endorsed by a Professional Engineer (PE) in accordance with BCA regulations. Pre-construction condition surveys of neighbouring properties are also typically carried out to document existing conditions and manage potential risks.

Ventilation and Dehumidification

Basements in Singapore’s humid climate require carefully designed mechanical ventilation and humidity control, as natural air movement is typically limited below ground. A dedicated system should be provided, incorporating fresh air intake, exhaust ventilation, and dehumidification capability to maintain a comfortable and healthy indoor environment.

Relative humidity is generally recommended to be controlled around or below 60–65% to reduce the risk of condensation, mould growth, and material deterioration. Without proper climate control, basements can become damp and musty over time, leading to discomfort and potential damage to furnishings and stored items.

What Goes in a Basement?

Popular uses for basements in Singapore landed homes include home theatres and entertainment rooms (naturally buffered for sound), wine cellars and tasting rooms (where temperature and lighting can be more easily controlled), home gyms and fitness areas, utility and storage rooms (freeing up valuable above-ground space), and car garages—particularly useful for sites with limited frontage or parking constraints.

Basements can also accommodate other functional or lifestyle spaces, subject to design and regulatory compliance.

Note: The use of basement spaces is subject to prevailing building and fire safety regulations. Habitable uses—such as bedrooms—may be permitted only if requirements for natural lighting, ventilation, and means of escape are fully met. Fire safety provisions, including protected escape routes and, where required, mechanical ventilation or smoke control systems, must be carefully integrated into the design. Early coordination with the project’s Qualified Person (QP) and fire safety engineer is essential to ensure compliance.

Cost: The Big Question

Basement construction is typically the most expensive component on a per-square-metre basis in a landed home build, due to the complexity of excavation, structural works, and waterproofing requirements.

For a single-storey basement in a Singapore landed property, costs can vary widely depending on soil conditions, site constraints, and the chosen earth retention system (ERSS). As a general guide:

• Excavation and earth retention systems (ERSS): approximately SGD 100,000 to 200,000+

• Structural works (reinforced concrete slab, walls, columns): approximately SGD 150,000 to 300,000+

• Waterproofing systems: approximately SGD 20,000 to 50,000+

• Mechanical & electrical works (ventilation, dehumidification, sump pumps, drainage, electrical): approximately SGD 60,000 to 150,000+

In total, basement construction costs commonly range from SGD 500,000, depending on design complexity and ground conditions. On a unit basis, this typically translates to approximately SGD 2,000 to 4,000+ per square metre.

For comparison, above-ground construction for landed homes in Singapore generally ranges from SGD 1,800 to 3,000+ per square metre, depending on specifications and finishes.

The premium for basement construction is therefore substantial. As such, basements are typically most viable when above-ground GFA has been optimised and additional functional space is still required, or where site constraints (such as limited footprint or parking needs) justify the investment.

Is a Basement Worth It for Your Home?

A basement can be a worthwhile investment if you have already maximised your above-ground GFA and require additional functional space. It is particularly suitable where soil conditions are favourable (as confirmed by a soil investigation), the project budget can accommodate the higher construction cost, and there are clear use cases that benefit from a below-ground environment—such as a home theatre, wine cellar, gym, or additional parking.

On the other hand, a basement may not be the most efficient solution if above-ground space has not been fully optimised, ground conditions are challenging (e.g. soft soils or high groundwater levels), or if budget constraints may impact the overall quality of the home. For purely storage purposes, above-ground alternatives are often more cost-effective.

Basement feasibility should be assessed early in the design stage. A soil investigation is strongly recommended, as subsurface conditions are a key factor influencing both cost and construction approach. With proper planning and engineering, a well-designed basement can significantly enhance both the functionality and long-term value of a home.

Considering a Basement for Your Landed Home?

Basement construction in Singapore requires specialist expertise in waterproofing, structural engineering, and regulatory compliance. Hitomo Construction has the experience and in-house capabilities to deliver a functional, dry, and well-ventilated basement space.

Reach out to us for a no-obligation discussion. Contact Hitomo Construction today or visit hitomoconstruction.com to get started.