The first question that potential and already established customes ask when they are looking for laser scanning services is: “How much it cost a 3D Laser Scanning survey?”.
It is certainly not easy to determine the cost of a survey, since there are a very large number of variablesthat come into play when evaluating the cost of an assignment, we will still give in this post some useful information that allow you to make an idea on how to quantify cost.
As noted the pros of using 3D laser scanner than traditional survey techniques are the optimization of data acquisition and at the same time the fact that you can be sure to acquire all the necessary information you need to represent the measured object. By the way there are many variablesthat must be taken into account when estimating the cost of a laser scanner survey, and among these the most important are:
Morphological characteristics of the building/plant/object;
The external form, the distribution of the interior spaces, the extension on multiple levels, the presence of complex decorations, are all factors that affect the cost of survey activities.
To estimate the right cost, it’s important to have a precise idea of the object’s characteristics performing an inspection or viewing photographic documentation supplied by the customer.
That dimensions affect the cost of a survey might seem obvious, and in fact in general terms, the larger theobject, the more time is required to detect it, the higher the cost.
However, there are some considerations to make on the subject.
First, the size of a property has to be considered in relation to its morphological characteristics, to survey and represent an industrial building open space of 10,000 square meters could cost less then the survey of an historic residential building on several floors of the total area of 1,000 sq.m..
Furthermore, a linear increase of the size of the property, not generally corresponds to a proportional increase in the cost, for obvious reasons linked to economies of scale.
Materials and color information
Using a 3D laser scanner with integrated digital camera, allow to captures in addition to geometric information also those relating to the color and material. The application of digital images on point clouds,allowing to deliver processed orthophotos, textured color facades, analysis reports of degradation etc.
The acquisition of this type of information during the scanning phase and the postprocessing of the data for the mapping of colors on point clouds, prolongs the time of data acquisition and postprocessing withconsequent increase of costs, therefore it is appropriate to evaluate the real need for the customer.
Level of accuracy
When we talk of greater or lesser survey’s accuracy we talk about the degree of correspondence betweenthe measurements and their ‘true value’. There are survey techniques that help increase the overall accuracy, and which require the use of high-precision instrument.
The 3D laser scanner on the market, enable to obtain an accuracy sufficient for the vast majority of applications, but if necessary their use can be integrated with topographic total station.
Level of detail
This aspect depends solely on what the customer expects to be measured and accounted for and the purpose for which the survey is commissioned. It ‘s always important, before a cost estimate, ask what will be the future use of the deliverables to be produced.
To give a practical example, the survey of only the total volume of a property and the architectural surveywith return at 1:50 of the same property, will result in time, resources and costs considerably different.
The phase of restitution and representation of the object measured by a 3D laser scanner, usually turns out to be the longest phase and wasteful in terms of working hours. It is preceded by a stage of processing of the raw data obtained from the scanner, which is done through the application of appropriate processing filters, the possible application of the mapping of color, the registration of the clouds and the export ofdata in formats readable by 2D/3D CAD softwares.
Then you can proceed to build the deliverables itself, through the creation of two or three-dimensional drawings depending on the request, and additional materials such as reports of survey, material schedules,virtual tours with 360° panoramic images, rendering, video and animations.
Also in this case, will be important to understand the customer needs and the use he will do of the final output.
As you can see, there are many aspects that need to be analyzed before we can properly quantify the cost of a survey, but we will try to give you an idea using two examples.
Survey of a residential building, situated in the center of a big city, extended on several levels, with total area of about 2,000 square meters.
In this case we can assume that the client needs are, in addition to the geometric information, also those relating to the mapping of the materials and color, and a reasonable level of detail. The property must be represented by plans, elevations and cross sections at 1:50 scale.
For this kind of activity is conceivable a cost in the range 5.000/15.000 € (April 2015) depending on the specific characteristics of the property.
Survey of an industrial complex consisting of warehouse, office building and accessory buildings with a total area of approximately 10.000 square meters. With an outdoor area of about 10.000 square meters.
In this case we are prompted to measure the overall complex, including the external areas to be measured with a level of detail which also includes all underground and installations. The properties will be returned without color mapping using plans, elevations and cross sections in 1:100 scale.
For this type of project is expected a cost that will stand in the range 8.000/20.000 € (April 2015) also in this case in dependence of the specific difficulties such as the presence of production lines in operation, the amount of plant and the morphological characteristics.
Over the years a company called Global survey services have performed dozens of building and industrial plants surveys, using different measuring techniques.
Often they happened to discuss the advantages and disadvantages of the use of more traditional survey methods, such as total station topographic survey integrated with direct acquisition of measurements with portable laser distance tools, compared to the use of 3D laser scanner.
When conducting the survey of a complex architecture, such as an historic building extended on several floors or an industrial plant, the most used techniques usually are:
In this article they focus on the pros and cons of 3D Laser Scanner vs. traditional survey techniques.
1. Direct survey with portable laser device
The survey is performed by acquiring the measures directly, distances such as the length and width of a room, the distance from an edge of the room to a door, the height from floor to ceiling, etc. The building being measured is divided into elementary geometries, usually different rooms or areas that compose it, and that will then be measured individually and connected to each other. The connection between the different geometries is performed taking care to detect common elements, which are usually represented by doors or passages between the different zones.
In this case it is very important to measure the thickness of the walls. Using this technique it is useful to try to acquire even overall measures that can be used to double check in the phase of connection of the various areas to increase the overall accuracy of the survey.
This is the least expensive method, as it’s not necessary any particular investment if not for the purchase of a good laser tool, but it is also the least accurate and suitable only for the measurement of simple building, small/medium size and that are developed on a single floor.
2. Topographic survey with total station integrated with direct surveys
This type of survey is suitable if you need to measure and represent real estate complex, with an extension above average, complex geometries that are extended on multiple levels. The survey is performed in two stages, the topographic survey and the direct survey.
In the first stage the surveyors measure with total station the position of a number of significant points, such as the vertices of the property measured, pillars, doors, windows, inner edges of the various rooms etc. These points will be returned with high precision in an overall coordinate system, and may be used to connect the different areas measured by direct method.
In the next step the topographic measurements will be integrated with a direct survey. The geometry of the different areas will be measured without the need to pay special attention to how these will be linked together, as for their global positioning the surveyor will use the topographic survey.
This working method requires an initial investment for the purchase of a good total station, the use of which allows to obtain an accuracy sufficient to definitely most architectural applications and/or engineering for which the survey may be required. However, does not allow to optimize the execution time necessary to measure by hand all the details that your customer needs you to represent.
3. Survey with 3D Laser Scanner
In the execution of a complex survey with 3D Laser Scanner you will not need to worry about run out of details, as the scanner will automatically acquire a so-called ‘point cloud’ with a resolution determined by the surveyor before starting the scan, depending on the size of the space to be measured and the size of the details that you want to acquire. The clouds acquired will then be connected to each other through the overlapping areas acquired from several different station points, using software that perform this type of calculation that is defined in jargon ‘cloud-to-cloud registration’.
The hardware performs a full scan, 360° horizontally and 320° vertically, in a time ranging from 1 to 30 minutes depending on the selected resolution and quality of the data to be obtained. The clouds acquired do not contain color information of the detected object, but only geometric information (X, Y, Z) and the reflectivity of the surface (usually a value from 1 to 100). If you want to get information about the color of the surface and link it to the points, it will be necessary after the laser scanning to capture a series of images through the digital camera that some laser scanners have built in or external camera appropriately positioned.
For surveys of particularly complex or extended properties, you can place on the spot, before the start of the scanning operation, a network of target whose coordinates are measured with a total station, which will serve to the positioning of the scans in an overall coordinate system.This lengthens the time of data acquisition, but avoids the cloud to cloud registration and increases the overall accuracy of the survey.
Using this technology the financial investment is higher, but the acquisition of point clouds allows to obtain a series of advantages, compared to the two previously described techniques, which can sometimes make the difference.
Let’s see them in detail:
Against these pros, there are also cons in the use of laser scanner technology, we see them are:
Published 27th April 2015
Point Cloud for BIM
Just trace over a Point Cloud – And you have BIM! – Sounds easy!!
A lot is talked about scan to BIM, where the common perception seems to be that, the point cloud data is traced upon and TADA!!! A BIM ready model is there. However working with point cloud is much more than just tracing over existing models, and only a modeler or a BIM expert can tell you that.
Working with Point Cloud and Scan to BIM challenges!!
Now, Point clouds can be highly complex, and working with these, requires experience and steth handling. However, the biggest challenge in most project is that the scanned data provided after the scanning exercise, have several missing sections and a lot of inconsistencies. This will happen most of the times, and it depends on the acumen of BIM experts and engineers how they handle these inconsistencies.
The BIM Technician has to study the point clouds and identified errors and missing parts. As the data volume of Point Cloud is high the engineer has to divide the data into subsections and this required a lot of management and collaboration between the team. The missing data also has to be constructed using engineering assumptions; this is done with the help of existing scanned data and reference images of the site
Now as note before converting point cloud to BIM is not just about tracing over the model, it demands a lot of complex modeling. Moreover, BIM experts working on such projects do not always have all the time at their disposal as the deadlines are normally tight.
Successful Project Management and Delivery
In addition to BIM capabilities, communication is also one of the prime aspects that leads to successful management and execution of a project. The way to succesfull delivery of a project is to always communicate every aspect of the design thoroughly with the client.
Ultimately after all the work, rework, communication, scanned data management and modeling activities are carried out, an Information rich, intelligent BIM model is ready. Clients can now used this model to schedule, plan and coordinate the project work. It has been noted that clients have managed to save around 20% costs on renovation projects as they have such flawless documentation available from day one. These information models, further may be optimized for sustainability & promote smooth and efficient facility management even post construction.
Choice of software: It is suggested to use tools like Kubit and Leica CloudWorx for laser scanning a facility, which give a partial BIM point cloud, and to use tools like Revit and Navisworks, unless specified otherwise bu the client. Revit is building design software, which includes features for architectural structural and MEP disciplines, thus allows development of an intelligent BIM. With Navisworks, professionals can review the integrated data and models, and exactly like the software claims, it helps coordinate and plan projects, resolve conflicts and gain control over the project outcomes.
It is interesting how point cloud models of various buildings, sections of buildings and landscapes can be easily obtained by using sophisticated laser scanners. However, these point clouds cannot be used right away for Revit family creation or BIM. Expert intervention is always required in order to convert these point cloud models into surface models that can be used for BIM. 3D Laser scanners are used to measure millions of points across a building and to capture all the details, dimensions and demarcations. These point cloud models are given to 3D modelers as input data in order to develop building information models. So what is the role of a 3D modeler here?
Working With Point Clouds and BIM – It Is All About Overcoming Challenges