Along with some of the documented recommendations from CSI and ASHRAE, there are some practical experience factors that can enhance the chances of getting what you specify. These include nontangible issues like good communication, documentation, knowing your client, managing the client, current codes and standards that impact product selection, today’s bidding environment, and various project delivery methods.


Communication with the owner/client is crucial to establish the functional requirements of the products to be installed. Documentation of design decisions, both in meeting memos and eventually in the contract documents, is important to getting the product that meets the required function. Documentation both to the owner and in the contract documents helps everyone remember why you did what you did in the design process.

Get the owners to “sign off” on important design criteria that affect product selections. Sometimes at the bidding phase or construction phase, you’ll need to revisit this documentation to ensure that what the contractor is proposing to install meets the goals of the client. The reasons behind all of the product features and attributes called for in the specifications are not usually documented in the contract documents; therefore, the contractors do not readily realize and understand why the engineer rejects certain submittals and substitution requests.

Involve and communicate with the owner’s maintenance staff. These are the people who will ultimately have to operate and maintain the facility. They also will likely be the first ones to notice and evaluate if the facility and the products are not performing as needed.

Know Your Client

Another key in the product selection process is understanding the type of client you are dealing with. There is a tremendous difference in the required function of a facility that is being built by a developer with short-term ownership interest vs. a facility being built by a private corporation or governmental organization.

The developer will generally be interested in the economics of the construction first, whereas the private corporation that will be responsible for maintaining the facility and the comfort and productivity of the occupants in the facility will be more interested in the technical functionality of the products. Likewise, the product selection criteria for products that will be installed in a highly technical research laboratory or industrial facility will likely be different than those selected for a commercial retail facility.

Managing The Architect and Client

Architects will often continually change designs and will not always allow sufficient re-engineering time. Let’s face it, it is much simpler to move a wall here or there without much effort in the drawings or CAD system than it is to recalculate the accurate lighting loads, ventilation requirements, heating and cooling loads, and sprinkler coverage requirements resulting from a simple wall location change. If the proper architectural facility usage design criteria are established at the start of a job, then the changes can be minimized.

A big component of managing the client depends on the competence of the architect to zero in on the building footprint and room layouts accurately the first time. This allows the rest of the design team the opportunity to be efficient in their work and not waste time making changes because of poor decision making by the architect and owner. More time can be spent “engineering” instead of chasing architectural changes and recalculating load requirements.

This is not to say that you shouldn’t be flexible and be a team player. After all, the design phase is the phase of a project wherein various alternative ideas are explored. However, once decisions are made and other work has been performed based on those decisions, then added fees may be appropriate to cover the cost of the other disciplines that are affected by those changes. An extended completion date may be in order to ensure that adequate time is allowed to make all of the required engineering calculations for the modified design.

The cliche “Poor planning on your part does not constitute a crisis on my part,” applies here. The point is to plan the work then work the plan, and to have respect for the other team members’ time.


There have been discussions about minimum code requirements vs. industry standards vs. what a prudent engineer would do when selecting equipment and designing systems for a building. If the concept of required function is kept in focus during the design process, then decisions about the type of design effort and equipment quality are made much easier with clearer vision by the whole design team in collaboration with the owner.

Over Design

Sometimes the term “over design” has been arbitrarily and maliciously used to critique an engineer’s work. This term is generally used by a third party who is trying to make a name for himself with the owner and who is, more times than not, simply using a slanderous marketing ploy. Usually, the party using the term is talking about a completely different set of “required function” parameters than was originally used to do the initial design. The term over design should only be used if the end result of the design phase is above and beyond what the design team and owner agreed to as the required functions of the systems and products that were selected to be included in the contract documents.

Many times, the owner/client is as much at fault as the professional design team when it comes to accusations of over design. An owner/client who does not understand the design process, construction industry, or the needs of the occupants, is not going to understand the importance of timely decision making during the design process, establishing design criteria priorities, and realistic budgets from the initial outset of the building design. Communication and documentation minimize and/or eliminate the concern of over designing a project.

Low Bid Wins

The “low bid” mentality often creates an environment in which professional budget hours are inadequate to truly design and engineer the facility by utilizing the most current calculation procedures. This is not to say that a D-B project, which uses the engineering staff employed by a D-B contractor, is any better. There may be a tendency in the D-B engineering groups to “swag” the design because they have the control and means of correcting any design deficiencies without the owner really realizing that there is a problem in the design. In a design-bid-build project, the contractor will generally point out to the owner any design issues that may cause problems. This inherently creates an adversarial fingerpointing situation in which the professional engineering firm is pitted against the contracting firm.

What Would You Do?

A healthy way to enter any design project is to treat all the decisions about product selection as if it were your money being spent. Would you spend the extra money for the added features that are available on the various products? Of course, there is always the “safety factor” concern that once the building is built it is out of the control of the designer and the contractor, so the designer typically wants to have a contingency plan built into the system. A safety factor can be considered as a way of allowing the facility operator to function in the extremes or when part of the systems fail to operate as intended.


When determining the functional requirements of a product, determine the needs vs. the wants of the owner. There is another category of wishes: if money was not a factor. This is where a skilled architectural and engineering project manager on a design team can make or break the profitability of the project for the AE firms. Timely decision making hinges on the owner knowing the difference between a need, a want, and a wish. Needs are essential, required functions; wants are luxuries; and wishes are dreams. Sometimes in our affluent country, we tend to get these confused.

That is not to say that all marble flooring or all advanced architectural elements fall into the wants or wishes categories. Sometimes the functional requirements of a facility really need these features to accomplish the goal of the building. On the same accord, there are times when it is necessary to install expensive HVAC systems in a facility to provide proper comfort conditions while sacrificing the more aesthetically pleasing, expensive architectural materials.

Budgets/Bids/Contractor’s Redesign

The subject of “redesign” by a contractor must not be overlooked here. When a professional engineer with an engineering consulting firm puts his seal on a set of contract documents, then he is saying that this design meets the minimum building code requirements. If the contractor’s engineers redesign the HVAC system, it is usually because the owner has changed the design criteria and generally has made first cost a higher priority than was originally agreed to when the consulting firm established the priorities early in the design phase. This is why it is crucial to document these decisions to help remind the owner that the consulting firm did its job in designing a facility to meet the owner’s functional requirements.

If the owner puts first cost as the number one priority at the last minute (the bidding phase), then this should not be a bad reflection on the consulting firm. This also points out the unfortunate reality that it is nearly impossible for an AE firm to establish a budget within the ±10% accuracy required by some contracts between the owner and the consulting firm. In many respects, bidding by contractors is not much different than bidding by professional engineers and architects to owners to win the design contract. In each case, the company will try to go in with as high of a number as possible but will readily negotiate to a lower price if they can be assured of getting the work.

A Team Approach

The selection and contracting of the professional consulting AE design firm and a contractor at the same time at the beginning of the design phase has been a successful way to approach a building project by an owner. The owner gets the independent engineering decisions of the professional engineering consulting firm (doing what they do best) and the independent construction knowledge of the installing contractor (doing what they do best). These two (or more) groups working together from the beginning yields more of a team approach.

To take it to the next level, consider hiring the commissioning agent at the beginning of the design phase. The commissioning agent theoretically monitors the design, construction, and installation evaluation process to ensure that the required functions established at the beginning of the design phase are ultimately delivered to the owner. A D-B firm can give a team approach also; however, the owner should still have an independent consultant or commissioning agent help monitor the required function decisionmaking process.

Sealing The Design — Engineer Of Record

If a job is redesigned, then it may be appropriate to have the contract documents resealed by the redesign professional engineer. The authority to make changes to the contract documents, that are part of the owner/contractor contract, belongs to the owner/client who has a contract with the contractor based on the contents of the contract documents. If changes are made to these contract documents, then the original engineer’s seal is not applicable to those changes unless that professional engineer agrees with the changes.

Planning Phase — Writing The Specification

The final selection of a product may be made by an individual (engineer, architect, or project manager) or by consensus of a group (design team or owner’s personnel). The product chosen to be used as the “basis-of-design” is documented in the contract documents by use of schedules, details, and specifications. The “specifier” will also be involved in this process and is expected to exercise professional judgment.

The specifications and the drawings are part of the contract documents. The contract documents are used to bid the work. They ultimately become part of the contractor’s contract with the owner. The writing of specifications should be an integral part of the design phase rather than left to the end. The contract documents that are prepared in the construction document design phase are used to convey the engineer’s “design intent” to the contractors who use these documents to bid the work to the owner. Specifications are as much a part of the contract document as are the details, schematics, schedules, and drawings. The specifications hold as much legal authority as any other part of the contract documents and should not be ignored by the bidding contractor.

The Four ‘C’s’

Although it is sometimes said that a “picture is worth a thousand words,” it must be remembered that the written specification can sometimes better communicate contract requirements than can the details, schematics, schedules, or drawings. The CSI Manual Of Practice states that specifications should be “clear, correct, complete and concise” in order to communicate the engineer’s “design intent.” One of the principles of these four “Cs” of contract document preparation is to “say it once” and not to repeat information that is in the specifications on the drawings and vice versa.

Specification Methods

There are four primary methods of specifying according to the CSI Manual Of Practice: descriptive, performance, reference standard, and proprietary (open and closed). Another consideration when writing specifications is the language used. This takes into account writing style, vocabulary, spelling, sentence structure, abbreviations, symbols, numbers, capitalization, punctuation, grammar, and page/section formats among other things.

A brief definition as quoted from the CSI Manual Of Practice will serve best to understand these methods:

  • Descriptive: Defines exact properties of materials and methods of installation without using proprietary names.
  • Performance: Specifies the required results, the criteria by which the performance will be judged, and the method by which it can be verified. The contractor is free to choose materials and methods complying with the performance criteria.
  • Reference standard: Requires a product or process to be in accordance with an established standard.
  • Proprietary: Specifies actual brand names, model numbers, and other proprietary information.
  • Closed proprietary specification:
  • Only one product is named;
  • Several products may be named as options; and
  • No substitutions.
  • Open proprietary specification:
  • Prices are requested for specified alternates;
  • Substitutions and cost adjustments may be proposed by the bidders; and
  • Products are allowed as substitutions after approval by AE.

Which method of specification is used depends on what one is trying to achieve with respect to giving more or less authority to the contractor to select a product to meet the required function(s). Most HVAC design projects use a “basis-of-design” product with a specification written in a modified open proprietary specification format (e.g., no alternate prices are required for the “or equal” manufacturers that are generally listed in the contract documents along with the basis-of-design product manufacturer).


According to the CSI Manual of Practice, there are two grammatical sentence moods that can be used in specification writing. The first is the “imperative mood” that uses the action verb as the first word of the sentence: “Suspend ducts from the structure.” The second is the “indicative mood” that uses the word “shall” in almost every sentence: “Ducts shall be suspended from the structure.” CSI recommends the use of the imperative over the indicative mood for specifications of products and equipment because it is more concise and easier to understand.


Start at the end. Once the vision has been identified and presented to the design team, start thinking about the end result. The planning phase of a project is the phase in which the professional engineers and architects must lead the client into making decisions that affect the facility design and product selection and specifications. In Part III of “Getting What You Specify,” you will learn about the evaluation phase of the product selection procedure: submittal reviews, holding the specifications, site visits, and warranties.