Why Are Renovation Projects Complicated?
Construction projects that require renovation are much more complicated compared to the construction projects for new buildings. In the case of new buildings, everyone works with the clear information, drawings, and documents that show accurate and predictable conditions. On the other hand, when it comes to existing buildings, the situation is quite different.
Here is a fact: the existing building stock will account for 80% of the buildings which will still be standing in 2050. In this regard, it is evident that renovation and retrofitting are the processes that are crucial for achieving sustainability goals and adapting buildings to the new requirements and conditions. However, such projects can face various difficulties.
And here is one of the problems: design clashes during renovation can result in delays, reworks, increased expenses, and difficult coordination among project teams. Such things as the duct that is planned to be installed above the ceiling and colliding with the beam or the new electrical run that crosses existing pipes happen in reality. Usually, renovation teams did not see these potential conflicts due to the lack of information.
Fortunately, there is something that changes the situation and this tool is called Building Information Modeling (BIM). BIM helps teams to see the existing structure in three dimensions and detect conflicts long before the construction begins. Thus, renovation becomes a precisely coordinated process based on a digital model of the building.
What Challenges Exist in Renovation and Retrofit Projects
To understand why such projects are so difficult, it is necessary to discuss the specifics of the challenges that such projects face.
Outdated as-built drawings and missing documentation. There are many cases when buildings were built decades ago. As a result, there are no accurate drawings and documents showing the original construction. Moreover, even if there are some drawings, they do not correspond to the reality as it is usually changed during the long-term period of exploitation.
Hidden structural, mechanical, electrical, and plumbing conditions. There are pipes, wires, and structural elements behind walls. They can differ greatly from what is shown in the drawings.
Uneven field conditions due to years of modifications. Buildings change and evolve over the time. There are modifications and repairs made by tenants, owners, and maintenance crews. As a result, the existing building does not have much in common with its original design.
Limited access during surveys and construction in occupied buildings. Most of the renovation projects take place in occupied buildings (for example, office buildings, hospitals, schools, or residential units). This complicates survey process and makes construction more difficult.
Increased risks of clashes between old and new systems during retrofitting work. If it is required to integrate new MEP systems with the existing structure, the number of possible clashes increases dramatically. All the new components should go around existing elements that are impossible to move easily.
What BIM Does in Renovation and Retrofit Projects
BIM solves all these challenges through the creation of an accurate digital model of the existing building. In this way, renovation teams do not have to work with partial information and rely on guesswork. The BIM model contains all the necessary data regarding the building conditions in geometrical form.
The BIM model includes geometry, building systems, and project information in one integrated environment. It is much more than 3D drawings – it is an intelligent database where every element contains additional information about itself, its properties, and constraints. In renovation projects, the BIM model shows both existing and proposed design and how they interact with each other.
BIM services help to make the right decisions before the construction starts. The use of BIM allows finding the issues in advance and solving them in the digital model, not in the reality, where the solution will be much more expensive and time-consuming. BIM includes the integration of geometric, structural, energy, and temporal data in order to predict interferences which could appear during the execution.
Scan to BIM: The Basis of Accurate Renovation Planning
The success of any renovation project depends on how accurately teams can understand the existing building and its conditions. That is why scan to BIM becomes so important in this context.
The process of scan to BIM consists of two major stages. First, the laser scanning and reality capture allow capturing real-site conditions in the form of point clouds (a set of millions of accurate measurements). The next stage is the conversion of scan data to BIM model. It becomes the reflection of reality in three-dimensional digital form.
The Sherbourne Street project in Toronto is a good example of how scan to BIM technology can be used to develop an accurate BIM model. The historic house was renovated and converted into modern senior housing. 3D laser scanning and LiDAR technology allowed teams to obtain very accurate data on interior and exterior of the building, and to build dense point cloud that was later converted into Revit model. This model turned out to be the hyper-repository of all the information which reflects the as-is state of the building.
Scan to BIM technology decreases the amount of guesswork and improves the accuracy of the BIM model for renovation and retrofit projects. It is especially helpful if there are outdated or missing drawings at all. For old buildings without any documentation, scan data can be used to build an accurate BIM model from scratch.
How BIM Prevents Design Conflicts
The key advantage of BIM in the context of renovation is the prevention of design conflicts. Here is how it works:
Clash detection helps to find conflicts at the early stage of the project. The software is able to automatically detect clashes between architectural, structural, and MEP elements. For example, the new duct that collides with the existing beam or the pipe run that crosses the existing structure are detected instantly. The issues are solved in the digital model before they appear in reality.
Better coordination among all project teams. The whole team (architects, structural engineers, MEP consultants, contractors) works in one common data environment and all the changes made by one of the parties are immediately seen by others.
Visualization of changes without any site disruptions. Designers can test several variants of renovation in the digital model without any changes of real building.
Accurate phasing for planning. In the case of occupied buildings where renovations are to be implemented in phases, BIM allows planning which areas to renovate first, how to maintain building operations, and how to transit to another phase.
Decrease in rework due to early detection of issues. The financial effect is rather obvious. For instance, implementing clash detection in one of the projects helped to save 4.63 percent of the total project costs. Another case study shows that the resolution of thousands of clashes before the construction starts helped to save tens of thousands of dollars in rework expenses. One of the projects related to the hospital and BIM allowed solving 92 percent of all the clashes and decreased field conflict reports by 78 percent.
BIM Use Cases in Renovation Projects
BIM can be used in the following renovation and retrofit applications:
Interior remodeling and space reconfiguration. Renovation of office layouts, retail spaces, or residential units is usually accompanied by BIM.
Structural strengthening and facade upgrades. When there is a need in adding structural reinforcement or updating building envelopes, the use of BIM allows knowing the existing conditions in detail.
MEP systems replacement or rerouting. The process of upgrading mechanical, electrical, and plumbing systems in the existing building is considered as one of the most difficult renovation tasks.
Adaptive reuse of old commercial, institutional, and industrial buildings. The conversion of the factory into apartments, office building into hotel, or school into community space usually requires a lot of BIM.
Energy-efficiency retrofits and sustainability upgrades. Energy modeling and analysis are possible with BIM and allow teams to find the most effective ways to reduce energy consumption and emissions of carbon.
Historic building renovation. Heritage projects require high accuracy and care in renovation and BIM allows documenting historic features, planning interventions that correspond to the style of the building and coordinating complex restoration work. The BIM technology has shown amazing results in one of the historic projects – the Guangzhou Restaurant historical building renovation. In the project, BIM allowed solving 2,120 instances of MEP clash, increasing the ceiling height on 150mm, decreasing project schedule for 35 days, saving costs for RMB 1.5 million, and reducing carbon emissions for 30 metric tons.
Key Advantages of BIM for Renovation and Retrofit
The advantages of applying BIM for renovation projects include:
Increased design accuracy by leveraging building data. Scan to BIM helps designers develop accurate models based on existing building data and conditions.
Increased speed of preconstruction decision making. When you have all relevant information about existing conditions and planned changes, decisions are made quicker.
Reduced project risks due to conflict identification. Finding possible conflicts in the digital model prevents them from becoming issues during construction.
Cost estimating and scheduling improved by having more accurate data. Accurate model allows for making correct quantity takeoffs and cost estimates.
Increased collaboration among all stakeholders. Having an accurate and transparent digital model helps in aligning efforts.
Increased chances to perform renovation works without any delays and change orders. When you resolve any potential conflicts in the design phase, there will be fewer delays during the renovation work.
Typical BIM Workflow for Renovation of Existing Building
A typical BIM workflow for renovation projects consists of the following steps:
Site survey and laser scanning. A 3D laser scan is performed to document the existing building. This creates a point cloud of the building.
Point cloud processing and modeling. Point cloud data is being processed and converted into a BIM model. The process called Scan to BIM.
Validation of existing conditions. The existing condition model is validated and adjusted with scan data. Structural components, openings and other elements are verified according to the scan.
Development of renovation design in BIM. The renovation design is done within BIM environment with new elements added to the existing condition model.
Clash detection and coordination. The clash detection software identifies potential clashes of the new and existing elements and new systems.
Construction planning and phased construction. Model helps to create a construction plan and do a phased execution, which is especially important for occupied building renovation.
As-built updates after construction completion. The model is being updated to reflect the changes done during construction work.
Why Professional BIM Services Are Needed
Although BIM technology provides lots of useful capabilities, the success of BIM application is largely dependent on how it is implemented.
Professional BIM team has skills and experience in scan data processing, modeling, clash detection and coordination. They understand renovation project specifics like the need for accurate existing condition, complexity of integration of new elements with existing building and the necessity for good inter-team communications.
Professional BIM services are helpful for complex renovation projects since they eliminate confusion and improve the coordination of work. Instead of dealing with different fragments of information in various file formats, project participants use a unified digital model as a single source of information.
BIM services can provide help with renovation project at each stage of work from initial survey to execution of renovation plans. From renovation consultant to contractor and building owner, everyone who has anything to do with renovation benefits from professional BIM support.
Conclusion
It becomes much easier to manage renovation project when BIM is applied from the very beginning. The process of guesswork, on-site discoveries and fixing problems turns into a coordinated workflow based on accurate data.
BIM helps to prevent any design clashes due to increased visibility, coordination and decision making. Using Scan to BIM, one gets an accurate digital model of existing conditions. Using clash detection, one finds and resolves any conflicts in the design phase. And with the help of collaboration, all the stakeholders get access to the same accurate information.
And the results prove it – less delays, rework, costs and better outcomes. With the building stock growing older, the need in renovation projects increases and BIM becomes a necessary tool for successful renovation and retrofit projects.
Ready to start your next renovation project with reliable BIM tools? CAD Drafting Services offers professional BIM modeling, Scan to BIM conversion, clash detection and coordination services for renovation and retrofit projects of any size. Our experienced team makes sure that your project begins with reliable information and proceeds successfully from design to completion.
Frequently Asked Questions
1. How does BIM help renovate existing buildings without design conflicts?
BIM helps to create an accurate digital model of the existing building using 3D laser scanning and point cloud processing. This model makes it possible to do an automated clash detection, coordination across disciplines and virtual testing of renovation options in advance before construction begins.
2. What is scan to BIM in renovation projects?
Scan to BIM is a process of collecting data about real-site conditions using 3D laser scanning or LiDAR technology and conversion of this data to a digital BIM model. This gives renovation teams accurate as-built data and helps them to avoid any guesswork and potential surprises.
3. Why is BIM important for retrofit projects?
BIM helps retrofit teams to understand current building conditions with precision, avoid any clashes between new and existing systems and plan upgrade of the building efficiently. It leads to less rework, surprises and more predictable project outcomes.
4. Can BIM be used for old buildings with no drawings?
Yes. BIM is especially useful for the buildings without drawings or outdated drawings because it is possible to create a digital model of the existing building using scan data. So BIM is perfect solution for historic buildings and buildings with incomplete documentation.
5. How does BIM reduce renovation costs?
BIM reduces costs through early conflict identification (and, therefore, quick fixes), improved coordination (fewer change orders), reduced rework (elimination of expensive on-site fixes) and more accurate planning and estimation (no waste and delays).
6. Which professionals benefit from BIM in renovation?
Architects, structural engineers, MEP consultants, contractors, project managers and building owners benefit from BIM during renovation and retrofit projects. Any participant of the renovation work has to deal with accuracy and coordination that BIM provides.