This division outlines the work required to prepare the land / site for future vertical construction. It ensures that the land is safe, stable, and appropriately modified for the planned building or infrastructure. The division includes surveying, demolition, earthwork, site utilities, paving, landscaping, and more.

This division will guide you on methods, materials, and performance criteria for external work, supporting both temporary and permanent site improvements.

What is clearing and grubbing?

The process starts with clearing the site. This means removing all vegetation, trees, shrubs, stumps, and debris.

Measurement is based on the net area cleared in square meters. All work must be verified by a site survey and measurements, preferably with calibrated tools.
In cases where trees or vegetation are salvaged for reuse, those materials are measured separately.

To avoid disputes, any differences between the as-planned and as-executed clearing must be documented on site.

You must also provide an allowance or provisional sum for possibilities of unexploded ordnance from World War 2. Report any presence of unexploded ordnance to the local police for proper disposal. DO NOT ATTEMPT to remove these ordinances with your site crew.

Practically, projects in the Philippines often face dense vegetation. Therefore, it is advisable to add an extra 5 to 10 percent to the cleared area to cover unexpected difficulties. Such a contingency factor helps account for denser or thicker growth than originally expected.

Excavation, Backfilling and Compaction

Excavation involves removing soil to create space for foundations, utility trenches, and other necessary cavities. It is measured by the net volume removed in cubic meters. The measurement includes a standard allowance for overbreak, often around 10 percent, which accounts for the extra soil that may be removed unintentionally.

In areas with loose or weathered soil—a common condition in many parts of the Philippines—this allowance may need to be increased slightly.

After excavation, backfilling follows. Backfilling is measured by the volume of soil placed back into the excavation.

There is always a question between loose soil volume and compacted volume. Excavation quantity is based on the dimension of the hole. However, when you price it, make sure you consider the loose volume that you acquired the soil.

Compaction typically requires a 95% compaction rate. This will mean that the volume of loose soil that was delivered by dump trucks will always be more than the actual compacted volume.

Account for this difference when you price your project.

Grading and Subgrade Preparation

Grading refers to the process of leveling and creating the contours of the site after clearing and excavation.

The finished grade must match the approved elevations of the drawings, and it is measured by the finished area (in square meters).

This measurement covers the entire area that will serve as the base for pavements, foundations and other building elements.

For subgrade preparation, the work is measured by the area that is prepared and compacted to create a uniform surface.

Any additional work done to stabilize the soil—using methods like lime stabilization, polymer add-ons or cement treatment—should be recorded separately.

Site Utilities

Utilities such as water supply system, electrical power distribution, sewer, drainage, and sanitation facilities require sub-surface preparations.

These utilities are grouped separately from the vertical utilities. Though some would group it all together in the electromechanical parts of the work.

Site Access, Fencing, and Security

Securing the site is essential to protect the project and maintain order. Temporary fencing is measured by the linear meter of installed barriers. Fencing must be installed around the perimeter of the site and at access points to control entry and exit.

In addition, security devices, such as temporary surveillance cameras and lighting, are measured by count or by the area they cover if applicable.
Gates should be counted separately from the fence. Additional features like electric fence is measured separately.

Environmental and Erosion Controls

These works include installing measures to control erosion, sedimentation, and surface drainage. Erosion control is typically measured by the linear meter of installed silt fences, while sedimentation controls may be measured by the area of sediment basins or diversion channels in square meters.

These measures are particularly critical in the Philippines, where heavy rains and monsoon seasons can cause significant soil erosion, muddy areas and soft soil.

These works can affect the mobility of equipment and personnel on site. Thus, this provision must be priced accordingly.

What are the new methods that can lower the cost and improve the efficiency of site construction?

Drone surveys and LiDAR scanning provide accurate topographic data faster than traditional methods.

Real-time mapping helps in volumetric calculations (cut/fill balance), reducing excess hauling costs.

GPS Controlled Excavators, bulldozers, and graders with GPS ensure precise cuts and fill.

Methods like horizontal directional drilling (HDD) minimize surface disruption and reinstatement cost for site utilities.

Pre-assembled utility vaults or manholes reduce site labor and improve installation speed.

These innovations can give you a distinct advantage when competing against traditional land moving methods.