6 Common Myths About Measured Building Surveys

Measured building surveys and 3D laser scanning are now widely used across refurbishment, heritage, facilities management and BIM projects. Despite this, there are still many misconceptions about how surveys work and why accuracy, control and methodology matter.

Whether you are planning refurbishment works, managing an estate, or preparing a building for BIM modelling, understanding the survey process can help avoid costly mistakes later in a project.

Below, we uncover six of the most common myths surrounding measured building surveys and laser scanning.

Myth 1: “If I stand still, I won’t affect the scan”

Unfortunately, standing still can still affect the survey.

Modern 3D laser scanners work by capturing millions of measured points from a fixed position. Anything positioned between the scanner and the surfaces being recorded can obstruct the data capture process.

This is known as occlusion — where objects or people block the scanner’s line of sight.

Think of a laser scanner as a highly accurate 360-degree camera. If someone is standing in front of a wall, doorway or feature, the scanner cannot record the surfaces behind them.

In occupied buildings, surveyors will often carry out multiple scan positions to minimise hidden areas, but clear access always improves the quality and completeness of the final survey data.

For this reason, surveyors may occasionally ask occupants to temporarily move away from areas being scanned.

Myth 2: “Those survey targets and tripods can be moved”

Survey targets, spheres and tripods are positioned very carefully and should never be moved during a survey.

In laser scanning and measured surveys, these control points are used to accurately register and align multiple scans together. Even a small movement can introduce errors into the final dataset.

Tripods are also commonly set up over precise survey control points. A slight knock can affect:

  • instrument position
  • level accuracy
  • scan alignment
  • survey control

On refurbishment and engineering projects, even small positional inaccuracies can create significant downstream issues during design and construction.

If equipment is accidentally disturbed, it is always best to inform the surveyor immediately so checks can be carried out before work continues.

Myth 3: “Measured building surveys are only used for floor plans”

Floor plans remain one of the most common survey deliverables, but measured building surveys are used for far more than producing 2D drawings.

Survey data is regularly used for:

  • refurbishment and redevelopment projects
  • BIM and Revit modelling
  • heritage recording and conservation
  • facilities and asset management
  • fire strategy and escape planning
  • landlord and tenant documentation
  • structural and engineering design
  • space planning
  • digital twin workflows

Modern laser scanning also allows buildings to be captured in high detail as point cloud datasets, providing an accurate digital representation of existing conditions.

This helps architects, engineers and contractors work from reliable information before design work begins.

Myth 4: “There is only one type of building survey”

Not all building surveys are carried out in the same way.

The appropriate survey methodology depends on the building, the required outputs and the level of positional accuracy needed for the project.

Measured building surveys are commonly categorised as:

Unconnected surveys

Individual areas are surveyed independently without positional relationship to surrounding spaces.

These are typically used for isolated areas where broader building coordination is not required.

Semi-connected surveys

Areas on the same floor are connected through survey control, while vertical alignment between floors is achieved using common building features.

This approach is often suitable for smaller or less complex buildings.

Connected surveys

All areas and floors are related back to a common survey control framework.

Connected surveys are generally used on larger, more complex or higher-accuracy projects where reliable coordination across the entire building is essential.

The required level of survey control should always be considered at the start of a project, as it directly affects how the data can be used later.

Myth 5: “Walls are straight”

In reality, very few walls are perfectly straight or perfectly vertical.

Buildings naturally contain variations caused by:

  • construction tolerances
  • settlement
  • age
  • movement over time
  • historic alterations

This is particularly noticeable in older and heritage buildings.

When creating drawings or BIM models from survey data, surveyors and modellers often use a best-fit approach to represent walls and features accurately while maintaining usable geometry for design purposes.

For example, a floor plan may represent wall positions at a specific survey height rather than showing every variation throughout the wall’s full height.

Understanding this is important when using survey information for refurbishment, fit-out or coordination work.

Myth 6: “Survey nails and benchmarks don’t do anything”

Survey nails, control marks and benchmarks are critical parts of many measured and topographical surveys.

These marks are used to establish:

  • survey control points
  • known coordinates
  • datum levels
  • positional consistency across the survey

They allow surveyors to maintain accuracy throughout a project and ensure different datasets relate correctly to one another.

In larger or phased projects, survey control can also help ensure future surveys align with previous work.

Although they may appear insignificant, these marks often form the foundation of the entire survey framework.

Why Accurate Survey Data Matters

Accurate measured survey data helps reduce risk throughout the design and construction process.

Reliable survey information can help:

  • minimise design clashes
  • reduce rework on site
  • improve coordination between disciplines
  • support BIM workflows
  • improve confidence in existing building information

As buildings become more complex and digital workflows continue to evolve, high-quality survey data is becoming increasingly important across architecture, engineering, construction and facilities management projects.

Need Advice on a Measured Building Survey?

At Laser Surveys Limited, we provide measured building surveys, 3D laser scanning, BIM-ready survey data and topographical surveys for projects across the UK.

If you would like advice on the most suitable survey approach for your project, our team can help explain the available options and required outputs before work begins.