Documenting Existing Conditions & Accurate Construction Modelling

There are always a lot of intricacies involved in construction projects as builders always require comprehensive planning to achieve meticulous and flawless execution. Understanding and documenting the current conditions of the construction zone is one of the major parts for engineers to craft accurate models for perfect execution. The reason is that these documents allow them to make informed decisions and allocate resources much efficiently. So here we are today; discussing the importance, benefits, methods, and challenges of construction modelling, for accomplishing satisfactory outcomes for both the builders and the end users.

What Are Existing Conditions in Construction?

Existing conditions refer to the status of a construction location and its proximate surroundings before the commencement of construction work. This includes several features, such as:

• Existing Structures: The present status of buildings at that location, which includes foundations, roof systems, and walls.
• Topography: Involves various land features including elevation, slopes, shapes, natural drainage, plus other features.
• Soil Conditions: The soil’s configuration, stability and bearing capacity.
• Utilities: Positions and conditions of existing gas, water, sewage, and electrical lines.

Why Understanding the Existing Conditions is Important?

Understanding existing conditions is paramount for planning, designing and executing construction projects as it provides a foundation for proper project planning, design, and execution, plus, it can impact the project’s scope, cost, and timeline. Engineers can make more informed decisions regarding the site’s layout, construction techniques to utilise, potential threats to look out for, and cost estimations. Understanding these key aspects beforehand significantly decreases risks of unforeseen problems, ensuring the project continues effortlessly and within budget, by addressing the specific aspects of the site in advance.

Methods for Documenting Existing Conditions

There are various methods and technologies used to document existing construction site conditions.

• Surveying

Surveying for construction is also known as site layout/staking. It is a process of the site’s measuring and mapping, determining property boundaries, rendering construction plans, establishing a site’s topography, marking the location of newly proposed structures, and locating other utilities.

Land surveyors apply numerous methods and tools like GPS (Global Positioning Systems), to accurately measure angles, distances, and elevations. The obtained data is utilised to develop comprehensive topographic maps or site plans that act as a base for the development of final product. Surveying can be used in conjunction with other documentation techniques, such as 3D modelling or Building Information Modelling (BIM), to visibly display the project’s starting point.

• Photogrammetry

Photogrammetry involves a thorough photo scanning of the construction site to collect data for producing a 3D model, just like in the laser scanning method. In this process, a specialist takes multiple overlapping images from different angles and uses the photogrammetry software to examine the photos and calculate the exact dimensions and positions of objects, generating very specific depictions of a structure.

This method can be utilised for capturing both extensive zones, including construction sites or landscapes, and minor details of objects and building structures; however, it is preferable for documenting existing site conditions with smaller room sizes that don’t have smooth, flat surfaces. It can particularly be used in developing as-constructed documentation for structure, where the workers need correct records of architectural features for expansion or remodelling.

• LiDAR

Known as Light Detection and Ranging, LiDAR is a technology used to accurately document existing site conditions by developing a thorough 3D model through laser scanning. It involves the usage of laser beams for measuring the distances between the scanner and surfaces to develop a comprehensive 3D illustration of the site or building.

Due to extreme accuracy of results, this scan is considered perfect for revamp projects, infrastructure upgrades, and building restoration where extremely accurate records are required i.e., a “digital twin” of the existing structure. It is also considered a very effective technique to capture a large number of data points in just a few minutes, diminishing the requirement of frequent site visits. This method is also considered useful for capturing uneven surfaces or large sites with complex details that are hard to document manually.

• Building Information Modelling

BIM for short, this digital method uses a set of software tools to develop detailed digital representations of a building or infrastructure project, capturing its physical properties, systems, design, and other relevant data through 3D modelling, created by combining engineering and construction data. Simply put, this method can provide a virtual experience of a road, freeway, building, bridge, or shrine before it is built.

These models are highly interactive and are useful for simulating potential changes or identifying contradictions between new and persisting conditions. It offers accurate assessment, design amendments, and project planning when renovating, restoring, or adding to an existing structure. The method proves useful in large, intricate projects where numerous stakeholders like architects, engineers, and contractors need to collaborate by providing all parties with access to accurate, updated data.

Key Advantages of Accurately Documenting Existing Conditions

Capturing accurate critical details of existing conditions is advantageous in a lot of ways, including:

1. Allow engineers and contractors to develop appropriate mitigation policies by knowing about the unstable soil conditions, potentially toxic conditions, or position of structural liabilities, amplifying the safety of working people on the construction site. Moreover, having detailed information about the site’s conditions, project managers can make sure the entire project is compliant to local building codes and safety rules.
2. Provide engineers and contractors with a clear insight of a site’s prevailing conditions, helping them develop effective designs and layouts. Information about natural features, such as slopes or vegetation allows the incorporation of these elements into their plans, resulting in enhanced practicality of the final build.
3. Enable stakeholders to make informed decisions by documenting existing conditions precisely to provide a clear view of a site and its existing structures and materials, preventing unforeseen costs, and making more precise and accurate price estimates.
4. Can prevent delays by ensuring the project team has the required details for proceeding confidently. The need for mid-project modification requirements can also be reduced by recognising potential challenges beforehand, keeping the project on track.
5. Enable architects, engineers, contractors and clients communicate better by having the same accurate information. Thus, they can easily align expectations and avoid misunderstandings about the project’s scope, design and timeline.
6. Accurate modelling of existing conditions helps architects and engineers to integrate new designs seamlessly within the already existing surroundings. As a result, new construction goes well or upgrades the current structures and landscape.
7. Help identify potential problems or flaws in a site or structure, alleviating potential risks during construction as a result and preventing costly errors.
8. Can serve as an important proof in case of disputes or claims related to the existing site conditions.

Tools & Technologies for Accurate Documentation

• 3D Modelling Software: Software like AutoCAD or Revit is utilised to design 3D models using survey data.
• Infrared Cameras: These devices can be used to spot thermal anomalies and recognise potential problems like structural faults and moisture.
• Traditional Surveying Gear: Conventional surveying gear includes tools such as GPS devices, theodolites, and total stations, which are used to measure and map land and structures.
• Laser Scanning Point Cloud Manipulation Software: This software processes and manipulates data captured by laser scanning tool to develop point clouds, which are 3D depictions of physical surroundings created by millions of points.

Challenges in Capturing Existing Conditions

Although useful, documenting existing conditions in construction projects can be hard due to multiple challenges workers have to face. These challenges can vary based on the site complexity, the tools used, and other environmental aspects. Here are some of the most commonly faced challenges while capturing existing conditions:

• Limited Accessibility: Several construction sites or edifices often have certain areas that are hard to access for documentation due to safety reasons, physical limitations, or logistical problems. This makes covert or underground structures hard to examine without using specialised methods and equipment.
• Complexity: It is often time-consuming for professionals to capture their existing conditions of large, complex structures and require expertise and use of special gear. Documenting interlinked systems, such as plumbing and electrical systems can also prove to be a hard process.
• Incomplete Documentation: In few cases, major details about the construction site may be missing, including the underground utilities and foundation information.
• Environmental Factors: Rain, high winds, and other severe weather conditions can hamper data gathering and investigation as well as pose security threats for inspectors and gear.
• Human Error: The inadequacy of human inspection can often occur while capturing the existing site conditions, resulting in taking flawed measurements, misinterpreting site features, or failing to capture critical details. Even if you use the latest tools, mistakes can still occur during data entry or during the conversion of raw data into usable formats which can be a cause of distorted information.
• Technological Limitations: Applying conventional techniques like manual surveys, may not deliver correct results or adequate details. Although technology like laser scanners significantly improves the precision and efficacy of documenting existing conditions, it can be costly to acquire or demands specialised expertise to operate.

Need Help with Documenting Accurate Existing Conditions?

Construction gurus understand the importance of having accurate details about the existing conditions of a construction site for successful execution of architectural projects. If you’re wondering where to find a reliable company that can provide professionals and specialised equipment for accurate construction modelling, then consider your wait over. HEB Contractors LTD provides you the ideal solution for all the specific requirements for your construction projects. Just call us at 01344 444929 or e-mail at info@hebcontractors.co.uk to transform the construction modelling process by integrating correct existing conditions documentation.