Preparing a Preliminary Design Report

Preparing a Preliminary Design Report Page 1

White Paper - Preparing a Preliminary Design Report Michael D. Doran, P.E. DEE, Adjunct Professor

Department of Civil & Environmental Engineering University of Wisconsin-Madison

May, 2011

Completion of a Preliminary Design Report is one of the major steps in completing an engineering project. The purpose of this “white paper” is to provide guidance to students in CEE 578 concerning such reports, including:

• Purpose and scope • Typical outline and format • Document/Summarize existing conditions • Forecast of client needs • Development and evaluation of alternative design solutions • Presentation of Opinion of Probable Cost information • Presentation of Proposed Project Schedule • Presentation of Preliminary Design Criteria and Layouts • Review of past similar projects

For discussion and guidance concerning plans, specifications, opinions of probable cost, project schedules, and engineering services agreements, students should refer to separate “white paper” documents or other information that has been prepared or provided for those topics.

Purpose and Scope A preliminary design report is usually prepared for multiple purposes, including: 1) to provide a basis for engineering design and other project recommendations made to the engineer’s client or project owner, 2) to provide the project planning and preliminary design information needed by a regulatory agency in order to gain pre-design approval, 3) to provide the information required by stakeholders and the general public as needed to gain their input to the project and, ultimately, their support, 4) should another engineering organization be responsible for preparing construction documents (including plans and specifications), to provide that engineering team with the fundamental concepts and bases of design, and, 5) to provide a record of the information used, needs to be met, alternatives investigated, public input provided, a record of major regulatory agency and stakeholder group communications, preliminary design criteria and layouts (site plans, floor plans, routes for corridors, etc.), and final recommendations to the client/owner concerning schedule and steps to be taken for project implementation. Simply stated, the preliminary design report must provide information to answer important questions related to the project, such as:


• What is needed? • What engineering solutions are feasible to meet these needs? • What solution is recommended and why? • What are the details of this recommendation (what, what capacity, where, what does it look

like, what materials of construction, what is the project life, what will it probably cost, what schedule should be followed, what does the owner need to do next)?

Figure 1 shows the major milestones of a typical preliminary design report, and their relationship to other major project milestones. The highlighted milestones are generally included in the preliminary engineering phase of a project. Prior to initiating a preliminary design report, the engineer should verify with the client/owner the purpose and scope of the report, as necessary to meet the needs of regulatory agencies and involved parties and, at least in general, determine the various documents and/or document sections to be provided such as: executive summary, summary document for public information, technical appendix materials, design criteria document, environmental assessment information, public meeting summaries, etc. Without care in preliminary scoping, it is possible that significant differences may exist between the owner/client and engineer’s understanding of the appropriate level of effort and document production for the preliminary design report stage of a project. The scope and level of effort for preliminary design services should be detailed in a formal agreement between the engineer and the client/owner of the project. Even the name or title of the preliminary engineering report may be client/owner or agency specific. Sometimes particular document names are used in individual disciplines of civil & environmental engineering (general civil, building, water, wastewater, transportation, etc.). Table 1 lists several common names that are used for preliminary engineering reports.


Although the principal purpose of a preliminary engineering report is to present engineering concepts, do not forget that clear and effective writing, and appropriate use of grammar and punctuation, will say much about the veracity of the report content. An engineer seen as taking little care in the preparation of a report may well be seen by her/his client/owner or others as taking little care in engineering matters. Proofread; use the spellchecker; recognize that the spellchecker may not tell “two” from “too.”

Typical Outline and Format Prior to finalizing the report outline and format, be sure to check to see if there are particular requirements to be followed to meet the needs of the client/owner or the principal regulatory or funding agency for the project. It is not uncommon for clients/owners or for governmental agencies that must grant approvals or permits for construction (regulatory agencies) or have or will provide grant or loan funding for the project (grantor agencies) to have specific requirements for report inclusions, outline or format. The form and method of delivery of the engineer’s report is also important to many clients. A preliminary design report for a complex and high capital cost project may, for example, be prepared by the engineer over many months. In such a situation it is usually preferred for the engineer to prepare “design memoranda”, preliminary draft sections of the report, etc., as the preliminary design is developed, so that client/owner review and concurrence with preliminary concepts may be obtained along the way. This helps to avoid costly and time-consuming re-grouping should there be later disagreement on major project concepts, necessitating a “redo” of major portions of the preliminary design development. The organization of a preliminary design report should make it easy to find information. Figure 2 shows a common method of organization.

• Cover – should be attractive, give specific information about the project, client name, project number designation, project title, etc. A photograph or other image that defines the project can speak volumes concerning the content of the report and provide an invitation to the reader to open the cover. Figure 3 provides an example cover from a preliminary report prepared by the firm CH2M-Hill.

• Front Matter – this includes transmittal letter, table of contents, list of figures, list of tables, and an executive summary. Always include a signed letter of transmittal. Engineering is a people business and the transmittal letter is your way to personalize the conveyance of the report and helps to build/establish a relationship. Clients/owners desire to work with engineers that are human, friendly, and the type of people that they would want to spend time with.


• Body of Report – this is the main narrative of the report, with pertinent figures and tables, usually arranged in a logical progression from an initial ‘statement of the problem’ to final recommendations and list of next tasks for the client/owner. Conclusions and Recommendations need to be easy to find and often are in a separate section.

• Appendix Material – a sure way to cause the reader to close the cover is to include highly technical information in the report body. If such information must be included, to satisfy regulatory agencies for example, relegate it to an appendix.

Your report front matter can either add or detract from your report. Are your table of contents and lists of figures and tables complete with respect to sections and major subsections, location and numbers of tables and figures, appendices, etc.? Are they easy to read and make it a snap to find information of interest to the reader? Is your Executive


Summary concise, easy to read, and provide a summary of key information on what the project is about, what is proposed, how much it is likely to cost, and the implementation time frame? Does your transmittal letter contain key information on what you recommend your client/owner do next? An important thing to always remember is that many of the members of your target audience have limited time available, or just will not want to wade through a technical engineering report. Pay particular attention to Table 2. These are important rules to remember as you prepare your preliminary engineering report. This effort has been your major focus for months, but it is only one item on the agenda of a busy council or board member. Design your report so that each member of your target

audience can easily find the information that they are looking for, and present that information as concisely as possible. Also remember that you are not writing in an effort to win a Pulitzer. Simple and clear language should be your goal. The body of the report should be divided into logical sections or chapters, consistent with the project, client/owner’s needs, and agency requirements. Table 3 provides an

example outline for the report body. This approach provides a logical progression through the development of the preliminary design, from definition of initial conditions to final recommendations, and can be an effective organizational format for readers. In some cases, the desires of the client/owner or convention will require that outcomes (such as Sections 10, 6, 7 and 8) be presented first, followed by the developmental information. Use which ever approach best meets the client expectations, agency requirements, and conventions for your type of project, but remember – your client/owner’s expectations and needs should be given first consideration. The actual formatting of sections, subsections and pages needs to provide a very readable document and a professional appearance. Strive for a consistent ‘look’ to your document with a uniform outline format and page numbering system, and uniform and attractive system of fonts and font sizes. Figure 4 shows an example of a typical approach. Looking at this figure your first reaction might be that there is a lot of wasted space. White space on the page greatly enhances readability, however, and techniques like providing a wide left hand margin (2.5 in or


so) and vertical line spacing (1.25-1.50 spaced vertically) are frequently used. The left hand margin (gutter space) can be used for placement of short summary statements, in a text box, to draw the reader’s attention to key findings and recommendations, and enhance there later recollection. Following are some examples of what might be placed in the gutter:

• A twenty-five year design population of 50,000 is recommended. • The roadway is recommended to be constructed as a boulevard to enhance

its appearance and to provide for effective stormwater management. • Duplicate process units are recommended for improved system reliability. • Natural lighting and vegetation within the courtyard will promote its use as

a gathering place. • Use of recommended materials and design features enhance sustainable

aspects of the project. • Value of methane gas generated will pay for project within 5 years.

As can be seen, your major takeaway points can be used as gutter notes in this way, so that the ‘browser’ type of reader can see your major points without reading the entire text, and can read more detail if desired in areas of interest. Use of a complimentary, but slightly larger and bold font will make the gutter notes easier to find and quickly absorb. Use simple tables and figures wherever possible to replace lengthy text. For information that you want the reader to be able to find again later, the information should be in a numbered table or figure rather than a bullet list. A bullet list containing important information will not appear in the lists of tables and figures, and therefore might prove difficult to find or reference later. The oft-quoted saying “a picture is worth a thousand words” is very applicable to preliminary design reports. Put it in a table or figure if any of the following are true.

• It is important summary data or information. • You likely would want to show it at a client or public meeting1. • You want to include it in the Executive Summary. • You want the information to be easily found or cited.

Effective use of tables and figures is another way that browser readers can quickly find the information that is of importance to them. Good use of tables and figures will make the text shorter and more readable, and will also force you to write your narrative in a manner that is most informative and geared towards presenting the material of importance. In fact, one of the most effective ways of preparing an engineering report is to first prepare the outline, next all the figures and tables, and finally prepare the text to effectively present and explain the figures and tables.

1 Coordinating your report and presentation graphics will also save you quite a bit of work. It also helps your client/owner, since they have previously seen the presentation graphics in report form.


When several members of your engineering team are working concurrently on report preparation, or to generally assist with numbering of tables and figures and future editing of the document, it is helpful to number tables and figures consecutively within each section (Table 3-1, 3-2….) rather than consecutively from the beginning of the document. This method is shown in Table 4 and it use avoids renumbering all the figures /tables and repairing their text references if a

new table or figure is inserted at some point during development of the document. In a large document this can require amazing effort (if consecutive from front is used) and all references may not be correctly found and repaired. Like Benjamin pointed out regarding his famous letter2, you should strive for a succinct text. Your client/owner is not paying you by the word, nor do they expect a thick report necessarily. They do expect a report that is easy to read and where the required information can be quickly found in a useful format. Your clients will not grade you by the mass of paper; neither will your judges or professors in this course. There is no need to produce a 50-page report when a 25-page one will suffice.

Document and Summarize Existing Conditions In many cases an early section of the preliminary design report will be devoted to summarizing existing conditions that are of importance to your project. This will provide the reader with the information required to form their own conclusions concerning the need for facilities to meet needs, or deficiencies with an existing facility. A transportation project, for example, might provide traffic count information to show that existing conditions are sub-standard. A waterworks project might compare water quality with regulatory standards, or available system pressure during firefighting conditions with required standards. A building rehabilitation project might summarize building deficiencies in relation to current code, list building structural and mechanical-electrical system problems and concerns, etc. This all is to provide the basis for answering the question: “why do we need to do anything at all?” Another good reason to document existing conditions would be if you want to use existing factors to help project future conditions. For a waterworks project, for example, you might want to use existing per-capita (per person) water use to project water use for a future design population.

Forecast of Client Needs Following a summary of existing conditions, you likely will want to include a projection of future needs that are driving design aspects of the project. This will focus on existing conditions, developing a

2 Benjamin Franklin, posted as a diplomat to France, once apologized to his president by saying: “I am sorry that this letter is so long; I did not have time to write a shorter one.”


proposed design year and service life of the project, future capacity requirements based on a design population, future usage, interim populations and usage rates if staging is to be considered, future regulatory requirements, future trends (such as sustainable design and impact on future usages), etc. The forecast of future needs is a very important aspect of the project, and must be developed with care. A corollary is that little additional effort in preliminary engineering should be completed until you have client/owner concurrence on the forecast future needs.

Development and Evaluation of Alternative Design Solutions Almost never is there just one design solution or feasible response to a client/owner’s needs. In most cases there are multiple feasible alternatives that need to be defined and evaluated to identify the one that appears most attractive. Usually the client/owner, and regulatory or funding agency, is looking to the engineer to identify and evaluate feasible options. Sometimes only two can be identified. More often there are many and the best three might be identified for comparative analysis. Graphics are a very useful tool in helping to present and describe alternatives. Schematics, block diagrams, general location drawings, etc. may be used at the alternative screening stage, and need only include sufficient detail to aid in understanding. Figure 5 is an example of the style used for an alternative process schematic in a professional report. Note the standard appearance format. A full page format is useful when a partial page size image will not be adequate for the information to be conveyed. A fold out (11 inch x 17 inch) tabloid size image may also be used if needed. Figure 6 is an example of such a figure used to show a proposed sewer route. Note that the title block is designed so that, when folded, the title and figure number of the figure is visible to the reader. To fold, the right edge is folded back to the left edge, and then back again to the right to the first fold. Larger sizes are sometimes folded and placed in a document holder at the back of a report, but this should be avoided if possible as this is difficult for the reader and the image may become separated from the volume. Note the use of satellite imagery in Figure 6. This can be of great help to the reader in getting a fix on the proposed location of a project. Whenever mapping of any kind is used, be sure to include a north arrow and a graphic scale. When alternatives are developed for comparative analysis they should be developed on the same basis to the extent reasonably possible (same design capacity, same design life, same general attributes). Prior to developing a preliminary design approach for a chosen alternative, the two or three options that


are selected as most feasible are developed to the point that they can be clearly described (site location, space used, capacity, performance), their ability to meet defined project goals, likely monetary costs forecast, environmental impact factors identified (as they may vary between the alternatives) and other pros and cons identified that may be important (such as ease of repair, reliability, ability to meet needs beyond the initial project life, ability to expand or upgrade, etc.). Developing this information and completing a comparative evaluation for the alternatives is often termed preliminary screening of alternatives, project focusing, etc. The degree of effort that goes into development of each option for this purpose is of necessity less rigorous than the effort that goes into final preliminary design for the selected design approach. The actual screening of alternatives will generally include a monetary cost element, and a non-monetary cost element that will consist of a comparison of environmental impact, goal achievement, ability to meet future (beyond planning period) needs, reliability, etc. Once monetary costs have been developed for comparative purposes, and non-monetary factors have been similarly defined, it is possible to make an overall comparison of alternatives to help with the overall selection of the most attractive design approach. Normally this is accomplished by first contrasting monetary costs, and ranking3 the evaluated options on that basis. Once that is accomplished, non-monetary factors are considered and contrasted between the most feasible alternatives that have been evaluated. Then, considering the non-monetary factors, the option having the most attractive blend of monetary cost and non-monetary benefits is selected. Note this is not totally an engineering decision, and the client/owner’s view should be

3 The classification of monetary costs of one alternative vs. another should consider the accuracy of the developed cost basis.


carefully considered at this point so that the “selected” alternative is arrived at with the client/owner’s concurrence.

Presentation of Opinion of Probable Cost Information Monetary costs should be presented and compared on a capital cost basis:

• Capital Costs – clients/owners focus on total capital costs, including: construction costs, costs of land and property rights, engineering costs, project administrative costs (costs of borrowing funds, legal and accounting fees, etc.), and a contingency. Use of construction costs for comparative purposes may be confusing or misleading for the client/owner. If you present construction cost projections, the client/owner may just be seeing dollars (you will be showing a lot of $$ figures) and may not appreciate that this is not the entire project cost. Be clear by presenting your opinion of all of the costs that are likely for the project.

• Present Worth Costs – Where future operation and maintenance costs are significant (utility projects for example), alternatives should be compared on a life-cycle cost basis by comparing the present worth or equivalent annual costs. All capital cost and O&M costs will be included in this analysis, as will future costs of major rehabilitation or replacements (equipment for example) during the life of the project. Salvage value at the end of the project life may also be considered in the analysis. Make sure that the project life, discount rate, and other life-cycle analysis methods used are consistent with your client/owner’s requirements, and also meet the needs of regulatory or granting agencies. Table 5 provides an example summary table that compares the monetary cost of alternative wastewater conveyance approaches on a Present Worth Cost (alias Present Value or Life-Cycle Cost) basis. More detailed information could be included in the report appendices.

• Significant Figures for Costs – Remember that you are developing your costs using various estimating methods and that they are not exact. It is therefore very misleading to a client to present cost figures to a great degree of accuracy. Seeing cost projections to the nearest $100 or even $1 will give the client/owner an unreasonable expectation as to the accuracy of the figures. Legal problems have developed for engineers in the past when their client/owner did not appreciate the accuracy of the projections and final costs were considerably higher than projections made during preliminary design. Use a rounding method for cost figures which is


consistent with the degree of accuracy of the figures presented. In some cases, your client may require that opinions of cost be developed using a provided-unit cost spreadsheet that will generate exact appearing dollar values given quantity and other inputs for various construction items. In that case a note should be added stating something like: “Our opinion of probable construction cost was prepared using the client’s latest cost-quantity template. The significant figures contained in the values computed using the template does not reflect the accuracy that should be assumed with the use of this method of cost projection. Actual project costs will depend on market and other factors at the time of bidding.”

• Current Dollars Basis – We all feel the impact of inflation and the change in the value of money over time. Remember that you are making cost projections today, but have no control or real basis for judging what the costs might be when a project is bid (sometimes several years later). Document the time basis (e.g., 4th Quarter 2011 dollars) of your cost figures so that the client/owner and others are clear as to their time-basis, and to help with extrapolation of the figures to a future cost basis at a later time if this is appropriate or necessary. One way to accomplish this would be to place a simple note4 on the bottom of each table where cost information is being presented. Similar to capital vs. construction costs, make sure that it is clear to the client/owner that the final project costs may vary from current projections owning to inflation or other factors.

A further point to be made concerning the development of cost information is that this information should be conservative from the viewpoint of the client/owner. Engineering organizations develop a reputation among the client/owner community concerning the reliability of the cost information they develop. You do not want to have a reputation as an organization whose projected costs for projects are low in comparison to costs actually incurred when projects are bid and constructed. On the other hand, you do not want to be unduly conservative, because developing projected costs that are unreasonably high will have the likely effect of discouraging your client/owner from implementing what might be a reasonable project. You might want to proceed by making the best projection of construction costs on the basis of the factors available, adding the cost of land and land rights, and including a multiplier to include engineering, other professional and administrative costs, and a contingency, this total multiplier being in the range of perhaps 25% to 50% of projected construction and land costs, depending upon the perceived accuracy of your cost projections and other factors. You should discuss appropriate multiplier values for cost presentation, and other factors related to cost development and presentation in the preliminary design report with your team’s industry mentor. For design-build projects cost presentations should really be made on a careful basis since your organization will have to deliver the project on the basis of your presented costs once agreed by the client/owner. If your project is being developed on a design-build basis, discuss with your team’s mentor the best way to present cost information in your preliminary design report.

4 Such as: “All cost figures are presented in 4th Quarter 2011 dollars.”


For additional information concerning opinions of cost, and presenting project cost information, please refer to the separate ‘white paper’ titled: “MEMORANDUM-Engineer’s Opinion of Costs.”

Presentation of Proposed Project Schedule One of the most difficult things for a young engineer to comprehend is how long it takes to implement a project from the beginning of planning to the end of construction and turning the completed project over to the owner. Even an efficiently run project will take considerable time. Some of the reasons for this include:

• Time to select an engineer and reach an agreement for services • Time for regulatory and funding agency approval of a preliminary design report, and

construction documents (including plans and specifications) if required • Time needed to obtain construction permits • Time needed to obtain site investigation reports (geotechnical, environmental, etc.) • Time needed to obtain construction easements • Time needed to finalize project financing arrangements (grants, funding agency loans, bond

sales) • Time for project bidding and the award of contracts

It is important for the engineer and the client/owner to be on the same page concerning the schedule at the outset. This will help avoid damage to the relationship between the parties should the client/owner have a different sense of the time required to complete a project than does the engineer. As a corollary to this, if you are advising a client/owner when they should initiate activity on a project, say in order to meet a regulatory or other very important end date, it is essential that you consider all of the requirements (such as above) to arrive at a reasonable timeline and date by which activity must commence in order to accomplish the completion goal. For additional information on project schedule requirements please refer to the separate ‘white paper’ entitled: “Phases of a Typical Water/Wastewater Project.” Although this was written with a water/wastewater project in mind, the requirements apply to many types of projects of a civil & environmental engineering nature. For your CEE 578 team project, you should consult with your industry mentor concerning timeframes that would be typical for a project of your type. For presentation of your proposed schedule use a simple table or Gantt-type chart in the report body, not a complex CPM diagram that is more appropriately placed in the appendix material.

Presentation of Preliminary Design Criteria and Layouts Preliminary design criteria and layouts will normally be part of a preliminary design report and will represent a preliminary summary of: “what, where, how big, what capacity, how many, how configured…” This might involve: routing locations for a new roadway, water main or wastewater interceptor; a preliminary site development plan; preliminary floor plans for major buildings; lists of


major equipment items (for a plant project, for example) together with the number of units and capacities; materials of construction and interior finishes; column and beam locations and preliminary sizes, etc. Preliminary criteria listings are best presented as simple tables showing key information for each project component. Preliminary plans and layouts are developed not to the extent needed for construction, but primarily as an aid to helping visualize where the proposed facilities would be constructed on the site and in relation to other structures, what major floor plans, etc., would look like and how buildings would be used, what would be the architectural appearance, etc., how would the project be staged if continued occupancy/use must be maintained, etc. Table 6 is an example of a preliminary design criteria list from an industrial wastewater treatment project. Plate 1 (attached) is an example of a preliminary design drawing showing the proposed configuration for the same project (as for Table 6) at the preliminary design stage. In addition to being an aid to the project design engineer, should the planning engineer not be engaged for that function, the preliminary design criteria form provide information concerning the project extent and scope, and thus the basis of the opinion of probable cost for the project.

Review of Past Similar Projects Your instructional team has an extensive collection of project documents completed by practicing professionals for real projects, as well as student project reports submitted by CEE 578 teams in the past. Take advantage of this collection by reviewing them to help you determine what might be the best way to present information for your project in your preliminary engineering report. In practice, engineers maintain an extensive library of past projects and a wise engineer will review several projects similar to his/her own prior to preparation of a preliminary design report to determine what information is typically presented and what type of presentation is most effective. Your industry mentor will likely have access to additional past reports to better focus what information would typically be provided to meet the needs of clients/owners and regulatory and funding agencies. You should also consult your industry mentor concerning the typical items to be included in your preliminary engineering report, format and approach typically used in the profession, examples of how preliminary design criteria and layout information, cost opinion and scheduling information are typically presented for you type of project, etc.

Additional Resources Some additional resources to help with preparation of your preliminary design report include some examples of preliminary design reports posted on the class eCOW2 site, examples of completed student reports in your instructors’ office, and examples provided by your mentor. Also, please refer to Guidelines for Technical Communication, prepared by Prof. Laura Grossenbacher, and posted on our eCOW2 site. Remember: Keep it Simple; Keep it Easy, Keep it Pertinent.


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Preparing a Preliminary Design Report