Are You Considering Value Engineering your Waterproofing Design? Costs, Benefits, and Consideration
- John D'Annunzio
- May 2, 2018
- 4 min read
In the last decade the term “value engineering” has gained prominence in the construction industry.
You might be asking, what is "value engineering"? It is quite a bit more than a catch-phrase, but it thrown around so often that it is in danger of losing it's meaning. The main objective of value engineering is to maximize the project’s function while minimizing the project cost. This process typically occurs during the pre-construction phase and provides an opportunity for the initial project participants (Owner, Designer, Project Manager/General Contractor) to review the design documents and project criteria. A functional analysis of the facility is conducted to determine key criteria for the building and offer alternative solutions for design, materials and application methods. Sounds good, right?
"Flatly put, if a building owner wants to cut costs, the waterproofing system is the last place to do so."
There can be some major benefits to value engineering. One major benefit is the cost reduction to the project that it can achieve. This is accomplished with less expensive alternatives to specified materials or systems. The key benefit – which is difficult to achieve – is to maximize the function of the building. This can only be achieved if the design solutions that are incorporated into final construction are more functional than the originally specified materials or systems. All of these things can amount to significant wins for the project stakeholders. In order for value engineering to be successful, success must be defined and project stakeholder all must agree to that definition.
Value engineering is defined as a success if it meets the following criteria:
Cost reduction: less expensive alternatives to specified materials, systems, or installation methods
Value-added: higher quality products or methods that will increase value for the client and overall satisfaction with the project
Life-Cycle Analysis: options that work to create a balance between initial construction costs and the long-term operational budgets
Maintainability: recommendations of systems and products that will reduce maintenance costs over the lifespan of the building
Risk mitigation: the value engineered option delivers the above benefits while minimizing risk to all project stakeholders
Waterproofing is an area of building design which eludes success in value engineering in many cases, and the owner should be duly cautious in this area. Specifically, value engineering exterior waterproofing and in particular any buried (below grade, garden/plaza deck, and planter) waterproofing element can be very risky.
Flatly put, if a building owner wants to cut costs, the waterproofing system is the last place to do so. Why? Because waterproofing is a small element in total project costs that represents a disproportionate segment of risk when it comes to building function and lifetime operational costs.
The reason for this is that in below-grade waterproofing the cost of excavation far exceeds the initial cost of application. For instance, an opening may be located deep below the surface requiring removal of overburden, such as trees, concrete, landscaping, followed by excavation of soil to reach the point of moisture infiltration. Once the repair is made everything must be put back. Exposing even a small area can run into the many thousands of dollars and be extremely disruptive to building operations and tenants. Now imagine if another leak or multiple leaks occur at different times? The costs are excessive. Unfortunately, we see this time and time again. Hundreds of thousands of dollars are spent remedying leaks in a system, when perhaps a few thousand dollars were saved during construction. Penny-wise, pound-foolish.
The acceptance of any value engineering proposal for waterproofing should be based on risk vs. cost basis. In consideration of the below grade waterproofing process, i.e. design and application, the best adage is too error on the side of caution. Therefore, the designer should always minimize risk despite any reasonable – or unreasonable – costs. With waterproofing you only have one chance to do it right!
Value engineering changes should match the due diligence required at the initial design stage. The project team should evaluate the materials/systems that are suggested and ensure that they are value added changes. For value engineering recommendations to be approved the changes to the material and/or application process should meet the requirements of proper waterproofing material selection.
The material selection process is divided into two equally important phases. The initial design phase involves consideration of membrane material suited for the specific building. Site specific issues and building requirements necessitate proper consideration. There are several site-specific considerations involved in the selection of the waterproofing material, some of the considerations are as follows:
Occupancy
Water Table
Soil Characteristics
Substrate Stability
Construction Sequence
Risk v. Cost
Proper membrane consideration should ensure that the membrane material meets all the following criteria:
Resistant to Hydrostatic Pressure
Chemical Resistant
Low Water Absorption Rate
Flexibility
Performance in High Ground Water
Ease and Safety of Application
The selection of the application process should ensure that the membrane is fully adhered to the substrate (concrete, wood, gypsum) and should be placed at all exterior substrate points down to the base of the structure.
Value engineering can be successful on waterproofing projects if the membrane provided meets all of the proper design considerations. If the membrane material chosen is not functional for site-specific requirements– and is only based on initial cost savings – the process may ultimately prove extremely costly and risky to the owner.
With buried and below grade waterproofing you only have one chance to do it right!
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