Making the Decision to Expand an Existing Facility
One way clients consider saving money on a construction project is to do an extension onto an existing building. I caution clients to be careful with building additions onto existing structures. The existing structural system may not have the capacity to support the additional load.
The thinking is that with an addition, the costs can be spread out. Typically, I have found that construction costs associated with additions (or renovated areas) may be more expensive than building a new structure from the ground up.
To determine the most cost effective way to go (new construction versus renovation/addition) may be to do a cost-benefit analysis. An objective analysis of the advantages and challenges associated with adding space to an existing building should be performed.
Assistance from a highly qualified architect to perform a cost-benefit analysis may prove to be well worth the fee paid. The analysis may include a life cycle cost analysis. The proposed design might affect things like the circulation paths that create code violations among other things.
Some Advantages of Renovating an Existing Building
Cost savings to the owner because the walls, ceilings, floors, and roofing system are already constructed.
Electrical system is already in place and it may be supplemented.
Plumbing and mechanical system may be in place and may service all of the current needs of the renovation project.
Renovation may be the best approach for an adaptive reuse of an existing space when the changes are minimal.
Some Disadvantages of Renovating an Existing Building
Some, if not all of the building may have to be brought up to current code requirement with respect to mechanical systems, electrical systems, plumbing systems, and structural systems. This would include infrastructure (toilet and ramps) that may need upgrading to meet the current handicap code requirements.
Unforeseen conditions may result i costly construction and design changes.
Estimated construction costs can include a larger contingency percentage than with new construction.
So, please consider and weight the advantages and disadvantages of a renovation project versus a new construction project. It may be more cost effective and efficient to do new construction.