One approach gaining serious recognition among environmentally conscious contractors is combining timber construction with height-adjustable pedestal systems. A properly built terrace made of timber joists supported on adjustable pedestals offers a gentle, low-carbon method of creating flat, durable outdoor surfaces over sloping ground, concrete slabs, or roof membranes.
Here is a look at why this combination works, where its environmental benefits actually come from, and how to get the most out of it.
1. Less concrete, less interference with the soil
Traditional terrace construction often begins with heavy excavation and litres of poured concrete for foundations. Concrete is a remarkable building material, but its production process is widely known to be highly carbon-intensive, accounting for around 8% of global CO2 emissions. Digging deep foundations also disturbs the local topsoil layer, damages the root systems of nearby trees and alters the natural water drainage within the plot.
Adjustable pedestals change this equation. Instead of pouring deep concrete pillars into the ground, pedestals rest directly on stable ground, compacted gravel or existing hard surfaces such as old concrete slabs and roof membranes.
In our production facility, we design adjustable pedestals specifically to distribute weight evenly across the entire base without the need for invasive foundations. By supporting the wooden joist structure on pedestals, you drastically reduce or eliminate the need to pour foundations. You keep the soil intact, protect groundwater infiltration paths and skip the carbon footprint associated with mixing and transporting heavy concrete.
2. The advantage of embodied energy in wood
Choosing wooden joists instead of steel or aluminium structures brings a significant reduction in embodied energy — the total energy required to extract, process, manufacture and transport a material.
Trees absorb carbon dioxide as they grow, locking it inside the wood fibres. When wood is sourced responsibly, this stored carbon remains trapped in the terrace structure for decades. Metal substructures, though durable, require high-temperature smelting and energy-intensive refining processes that generate significant carbon dioxide emissions before the material even reaches the construction site.
To make sure your wooden substructure is truly sustainable, pay attention to the following details:
- Sourcing and certification: Look for wood certified by organisations such as the Forest Stewardship Council (FSC) or the Programme for the Endorsement of Forest Certification (PEFC). These standards ensure that the wood comes from responsibly managed forests where trees are replanted and ecosystems are protected.
- Species selection: Naturally rot-resistant local species, such as western red cedar or black locust in North America, reduce the need for aggressive chemical treatments and limit transport-related emissions.
- Preservation: If you use pressure-treated softwood joists, look for modern, copper-based preservatives with a low volatile organic compound (VOC) profile instead of older, more aggressive chemicals.
3. Verification of environmental claims: Environmental Product Declarations (EPD)
Given the prevalence of greenwashing in construction, relying solely on material selection is not always sufficient for commercial specifications or rigorous residential projects. This is where Environmental Product Declarations (EPD) become essential.
An EPD is an independently verified, standardized document defining a product's environmental footprint throughout its entire life cycle — from raw material extraction and production to transport, installation, and end-of-life disposal. It can be treated as a transparent "nutrition label" for building components.
- Data-driven choices: When choosing both timber joists and pedestals, checking published EPDs allows you to verify the actual global warming potential (GWP), embodied carbon, and recycled content rates, rather than relying on general claims.
- Green building certification points: If a terrace project is to achieve green building certifications such as LEED, BREEAM, or WELL, using pedestal and timber systems with third-party verified EPD documentation directly earns points in the sustainable material sourcing categories.
As a manufacturer of adjustable pedestals, providing transparent EPD data gives architects and contractors the verifiable evidence needed to accurately calculate a project's total carbon footprint.
4. Extending the lifespan of wood through airflow and drainage
The biggest threat to any wooden structure is trapped moisture. When wood lies directly on damp ground, saturated concrete, or in standing water, fungal decay and rot quickly appear. Replacing a rotten terrace structure every ten years completely negates any initial ecological benefits.
And this is exactly where raised pedestal systems prove their worth.
By lifting wooden joists above the ground or substrate, pedestals create a continuous air gap beneath the terrace. Air circulates freely around the wood, drying out moisture from rain or melting snow. Rainwater flows under the pedestals to drains instead of accumulating around the base of the wood.
When designing our pedestal heads, we build in dedicated channels and socket mounts for wooden joists. This keeps the wood raised and stable while ensuring there is no direct contact between the ground and the wood. A dry joist is a durable joist, and doubling the lifespan of the substructure halves the material footprint of the terrace in the long term.
5. Easy slope correction without mass terrain leveling
Not every home garden or roof is perfectly flat. In reality, most of them have a designed slope to drain water away from buildings. Traditional installations often deal with terrain slope by renting heavy earthmoving equipment to level the plot — a process that consumes fuel, removes topsoil, and creates a risk of erosion during heavy rainfall.
Adjustable pedestals solve this problem through mechanical height adjustment and slope compensation. Instead of forcing the landscape to fit the terrace, the pedestals adapt to the landscape.
Thanks to screw mechanisms and self-leveling heads, the installer can set the pedestals at different heights on uneven surfaces, precisely leveling the substructure down to the millimeter. This avoids extensive terrain leveling, reduces fuel consumption by heavy machinery, and enables construction on difficult slopes with a minimal footprint.
6. Reusability after end of service life and low-impact dismantling
Eventually every structure reaches the end of its service life. The main drawback of traditional concrete-bound terraces is dismantling: breaking up concrete foundations with pneumatic hammers, hauling crushed waste to the landfill and restoring the damaged ground.
The system of wooden joists supported on pedestals is inherently modular. Because the joists rest in the head slots rather than being embedded in concrete, dismantling the system is simple and non-destructive:
- Reusable support: Pedestals made of high-density polypropylene are resistant to weather conditions and do not degrade underground. When the terrace is ultimately decommissioned, the pedestals can be unscrewed, cleaned and reused in a new project or passed on to standard plastic recycling streams.
- Recoverable wood: Because the wooden structure remained dry and raised above the ground, large parts of the joist structure often remain solid enough for reuse in construction, for raised garden beds or for wood recovery.
- Restored ground: After lifting the pedestals and wood, the ground underneath remains largely intact and ready for immediate replanting.
Keeping balance in your project
Building sustainably does not mean giving up structural integrity or design freedom. By combining certified wooden joists with adjustable pedestals, you gain a flat, stable and beautiful outdoor space that works with the natural environment instead of fighting it.
If you are planning an upcoming terrace project and want to check how raised pedestal systems can fit the conditions of your site, contact our technical team. We can help you calculate load capacity, account for slope differences and select the appropriate height ranges for your structure.
