Refurbishment and repairing of buildings are often needed for various reasons. It is more economic to modify an existing building than building a new one. More and more clients, especially commercial establishments are adopting modifications to cut the cost at this time when the economy is reeling.
The refurbishment industry provides a lot of civil engineering job opportunities for the skilled engineers. Technical understanding of structural engineering helps a long way in becoming an expert in this field of Building Renovation. One also need to have an eye to detailing and skill to capture site requirements to efficiently under take refurbishment and Building renovation works.
Understanding the scheme and load path of an existing building is very important to undertake building renovation.
This blog will explain the need of building modifications and the minimum steps needed to undertake a modification to existing buildings.
Why Refurbishment?
There are many reasons that a client / a building owner wants to undertake a refurbishment or a repair of building structures. Some of the main reasons are listed below this section.
If you know more reasons, please feel free to comment in the comment section below the blog. Also comment if you have any questions.
Non functionality
A buildings life is not unlimited. As the building ages, it deteriorates and hence will need a repair for performing its functionality. A functionally compromised and aesthetically poor building will need upgradation. The building should be structurally safe as well and hence structural repairs are inevitable.
In developed countries, periodic inspection and regular maintenance are mandatory as per the building rules. A stability certificate is mandatory for old buildings to be continued to be used. This keeps the building safe against failure. Such rules do exist in some of Indian city bylaws as well but rarely are they stringent.
Many clients prefer to repair an old building than rebuilding due to affordability reasons in this time when the prices of construction materials are sky rocketing.
Functional changes
Many times, the functional use of the building change and the load carrying capacity or demand of the building changes as well. In India, it is quite common that a residential area develops in to a commercial place and the owner wants to convert an old house in to a commercial space.
These demands strengthening of structural members by adding beams or any other structural means.
Sometimes, a major rehaul may not be needed. However, it is important that a structural engineer looks in to the load demand change and rework the capacity of members.
Upgrades & alterations
Strengthening of the structure may be needed when there are upgrades and alterations needed. The kind of alterations can be addition of lifts or stairs. Changing the wall layouts and so on.
All of these modifications, results in changes in the loads and the load path or the load transfer mechanism. It is mandatory that a structural engineer is on board and he or she looks in to the changes and ensure the changes can be safely incorporated.
Accidents
Sometimes, an accidental collapse or failure of a building or a structural member force repair. It can also be a natural disaster like earth quake that creates the requirement of refurbishment.
Meeting the building rules
Many owners violate the building rules and build initially. Later there may be requirement from the authorities to demolish the deviated portion. This will force the owner to break structural members which will need a structural expert’s attention.
Historical Value
Some buildings are heritage buildings and it has a huge historical value. Such buildings need maintenance and modifications over a period of time. Many such buildings are government owned buildings. Archaeological Survey of India or any related government agency will look after the maintenance requirements of such buildings.
Some buildings will also be sentimental to a client due to various reasons like the building being built by his parents or some one he values or even a school he studied.
These are only some of the reasons that demands refurbishment of a building. There can be many more reasons, specific to a project or a building. This needs to be taken up on a case by case.
Many building owners are not sure of how to go about the refurbishment works. They think that a civil or a structural engineer or a building contractor can do this with out any information from their end. This is not right. The entire information related to the existing building will be needed to safely and efficiently undertake these kinds of repairs.
Also, most consultants are not technically equipped to understand the refurbishment needs. Many are skeptical to take up this kind of work as the client is not really willing to spend money on consulting as they are not really aware of the needs and challenges involved and the value an experienced consultant can bring in.
Minimum steps needed for refurbishment
It is mandatory that a specialist takes up such works and all information is made available to the specialist so that the building refurbishment is safe and effective.
The bare minimum requirement is listed below. These steps are very important to have an efficient work. The clients should be educated of these steps.
Define the Requirement clearly
The exact requirement of the new refurbished building needs to be decided prior to start so that every thing is planned well and all construction sequencing is planned and structured. This step also will help to freeze the requirements in the next steps listed below. For that matter, any project needs a proper planning. Any re work on an existing building is even more important as a minor mistake can prove fatal.
Existing Drawings
All existing structural drawings are needed to ensure possibility and safety. Many times, the refurbishment is of large scale like adding a floor or changing the usage which will all affect the loads in the building. This needs to be properly attended.
To back work the capacity of all structural members like footings, columns, beams and slabs, it is required to have the existing drawings.
Sometimes, the existing drawings may not be available. A proper survey of the existing building needs to be undertaken so that all possible information is captured.
Survey / As built Drawings
In spite of having all structural drawings, a survey of existing building needs to be carried out. This will help to capture any changes or alterations done in the building.
This is even more important in the absence of structural drawings.
Please be aware that, if the building alteration is significant, to check the structural design, you may even have to excavate around the building and identify the size of footings and its founding depth.
All information about the existing building shall be captured in this survey. The beam & column positions, its sizes, rebars in the structural members and so on. If the extent of rectification is significant, even footing sizes needs to be captured and you may even need excavation around the footings.
There are agencies who does survey and make as built drawings.
Non-Destructive Testing
Non destructive testing (NDT) may be needed to ascertain the strength and quality of concrete if the building repair is significant. Also, if structural drawings are not available, a scanning of the structural members will be needed to find out approximate numbers and sizes of rebars.
These NDT reports needs to be carefully studied by the structural engineer to see if there is any strength issue already. Also based on this study, we can back work and decide what modifications can be undertaken in the building structure.
Design & execution
Once these checks above are established, a specialist structural engineer should look at all of these data and work out the structural feasibility by a structural analysis and design. The buildability of the new work should be carefully thought about. Special emphasis to be provided for any interfaces in structures. A specialist contractor should execute the work under the supervision of a structural engineer.
This step is very important for the safety and wellbeing of the building structure.
Summary
Refurbishment and alteration of buildings is a specialist work. A structural engineer has a lot of roles to play in this kind of works. There are many firms in to design of such additional works.
Some clients don’t realize the importance of structural aspects in these steps. Many thinks only about the aesthetics part after the renovation.
However, many clients are now educated and appreciates the need. It’s a matter of time that this area becomes more professional. There are building regulations around refurbishment but it needs to be made more stringent.
Generally, one should have sound structural basics to work out solutions to additional works and alterations. Young civil & structural engineers can look at these specialists’ jobs and improve their technical understanding to fit this challenging role.
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