Sustainable Timber Resort Integrating with Mandai Rainforest

Mandai Rainforest Resort blends nature, conservation, and sustainability in its design. As Singapore’s first Super Low Energy (SLE) resort and a recipient of the BCA Green Mark Awards 2024, it sets a new benchmark for environmentally responsible hospitality.

Set within 4.6 hectares overlooking the Upper Seletar Reservoir, the resort integrates seamlessly with the Mandai Wildlife Reserve. Its most iconic feature is the series of 24 elevated seed pod-shaped treehouses, designed to sit lightly within the rainforest canopy.

Accoya® timber was selected for the ceilings, soffits, and curved exterior screens due to its exceptional stability, durability, and low-toxicity performance in tropical climates. Each cubic metre stores 944 kg of CO₂ while only 88 kg is emitted during production, supporting Mandai Wildlife Group’s long-term carbon goals.

For the external decking, the project used Onewood, a reconstituted, high-performance timber engineered for outdoor durability and consistent structural behaviour. Its moisture resistance and uniformity make it suitable for rainforest pathways and elevated platforms, complementing the use of Accoya® in the pods’ main structural envelope.

Sustainability Highlights

• Material Excellence
  Non-toxic, certified timber materials were chosen to deliver durability, stability and minimal environmental impact.

• Wildlife Preservation
  Sustainable timber construction helped reduce disturbance to the surrounding rainforest ecosystem, protecting biodiversity across the reserve.

• Green-Certified Construction
  Every phase of the material lifecycle — from production to installation — aligned with Mandai Wildlife Group’s conservation-focused sustainability goals.

Calvary Carpentry’s Timber Journey

Calvary Carpentry has been involved in the Seed Pod Treehouses since 2019, with prefabrication and installation progressing over the past three years. This stands as one of the most technically demanding projects undertaken by the team.

Unlike conventional timber builds, the pods feature continuous curves from ceiling to soffit, with almost no straight lines aside from the sunscreens. To achieve the organic geometry, the Calvary team had to stretch, twist, and profile each piece of timber with precision — ensuring it followed the pod’s form without compromising structural performance.

The complexity required constant monitoring, prototyping, and refinement. Over the years, the team introduced improvements such as optimising ceiling drainage and refining interior spatial allowances. Each enhancement was informed by on-site testing and close collaboration between architects, profiling technicians, and the installation crew.

This project reflects Calvary Carpentry’s belief that timber structures should be both meticulously crafted and built to endure Singapore’s tropical climate. From the curved Accoya® soffits and screens to the precisely installed Onewood decking, every detail required patience, technical expertise, and an unwavering commitment to quality.