A building layout shows the property’s floor plan on the ground surface. Unlike the building plan which is drawn to scale on a sheet of paper, the building layout is done on the ground surface to show a structure’s position.

It indicates the building’s plan on the ground surface and precisely defines the position and orientation. We prepare a building layout after the completion of a conditional survey.

The building layout acts as a guide during construction. Construction can commence after the finalization of the layout. This article discusses all you need to know about a building layout.

BUILDING LAYOUT – TERMINOLOGY YOU NEED TO KNOW

To understand the layout settings of a building plan, we need to know some associated technical terms. Below are the most common building layout terminology terms.

TEMPORARY BENCHMARK (TBM)

A temporary benchmark refers to a fixed point of known elevation used as the arbitrary point for the initial level works. It is usually at the ground floor level. And this benchmark kicks off all setting out work.

The TBM typically relates to permanent fixtures like manhole covers or a firmly driven post. After identifying the TBM, a peg or steel angle is placed to mark that place.

The TBM should be clearly marked on all drawings, and all the dimensions should be in meters to three decimal places.

BASELINE

The baseline is the building line where all the setting out work commences. Often, the baseline meets the building line, which is the project’s boundary line. Existing roads or local authorities generally determine the building line.

The baseline demarcates the property boundaries, and once you have it, you can easily mark the corners of your building.

HORIZONTAL CONTROLS 

After determining the baseline, you need to develop horizontal controls that help you mark all other specific points. It is essential to have numerous horizontal controls so that not all need to be taken down if one is taken down.

The horizontal controls always have their coordinates with respect to specific issues on-site and help one quickly locate the plan’s points on the ground.

VERTICAL CONTROLS

Vertical control points are typically established relative to specified datum levels. These datum levels are often timber posts in concrete. However, it can also be a road or a nearby land feature.

Horizontal and vertical controls are usually established using theodolite or similar surveying instruments during the leveling phase.

After determining these points, you can now draw your building’s layout. Any changes should be noted in the drawings to avoid any confusion.

The potential impact of not correctly considering the building layout

Not correctly considering the building layout can cause a few things to go wrong. Some of the common mistakes are discussed below.