When we think about building design, we tend to imagine architects and engineers drafting construction plans. Although the plans are fundamental, by themselves they are not enough to describe exactly what is required - some information is too extensive or detailed to be included directly on drawings.
To be complete, a set of design documents must also include technical specifications. These specifications are detailed descriptions prepared by an architect or engineer for the contractor, indicating all the requirements that cannot be represented or described clearly in drawings.
A project is only accepted if it meets design specifications. In other words, they are mandatory for the corresponding project, even if their requirements exceed local construction codes.
The opposite does not apply: Architects and engineers cannot design a project that falls below the minimum performance requirements in applicable building codes. If this happens, the NYC Department of Buildings rejects the construction documents and returns them for redesign.
Without specifications, client requirements cannot be communicated effectively to contractors. In addition to being code compliant, design documents must also provide clear instructions to complete the project as visualized by the owner.
Make sure your project design is well documented.
Project specifications are contract documents, which gives them legal character. They are also useful after project completion: property managers use them as reference for maintenance and building upgrades. Ideally, all building modifications should be reflected in drawings and specifications so that they remain useful - outdated documents are not very helpful in a building that has been modified extensively.
Well-written specifications also improve project communication: misunderstandings between the client and the contractor less likely if they have a clear reference document.
Best Practices When Writing Specifications
When writing project documents, you should follow the seven C’s: clear, concise, correct, complete, comprehensive, consistent, co-ordinated. These apply not only for textual documents, but also for information provided directly on drawings and schedules.
The Seven Cs
Use plain English to make construction documents understandable for all parties involved. To avoid confusion and clarifications, technical and legal language should only be used when necessary.
The text should avoid repetition and unnecessary words, but this must not be overdone to the point where key information is omitted. For instance, a description like “contractors installing equipment on the site should ensure that that said equipment is in all cases installed plumb and level as per manufacturer’s recommendations and specifications” can be shortened to only “install equipment plumb and level” and no information is missing.
The professional writing the specifications must ensure they provide correct information. Special attention should be given to code section numbers and other cross-references. However, there is no need to copy the whole text when another document is referenced.
Project specifications should not assume the reader already knows a key fact - all relevant references must be included. For example, an industry-specific equipment rating makes no sense unless the corresponding standard is mentioned.
Specifications must cover the requirements with sufficient depth, while avoiding excessive and irrelevant information. For example, relevant features of equipment should be described, but there is no point in describing functions that are not used in the project.
Terminology and style should not change between different sections of a specification document. This improves readability and prevents misunderstandings.
Project teams should work together to avoid contradiction and conflict between different sections of a specification document. Coordination becomes much simpler with modern design and project management software.
Understanding Plans and Specifications Better
Project designs normally have a dedicated specifications document, but note that additional requirements are often written on construction plans. Typically, the first page of the plans provides general notes, and additional notes may be found on plans dealing with specific building systems, or in material schedules.
Construction plans use symbols, abbreviations and numbered notes to improve clarity and save time. The meanings of these symbols and abbreviations are normally provided on tables, which are included along with the plans. The project staff should not assume the meanings of symbols and abbreviations without checking the reference table, since many are not subject to standards and chosen freely by designers. Of course, designers should also make their drawings clear - a good practice is keeping symbols and abbreviations consistent for a given set of documents.
Design documents should provide all the information needed to build the project correctly. Nobody should be guessing requirements, and if this happens it means the information is misleading or unavailable. Staff members and contractor personnel should not limit themselves to reading only the sections related with their technical field, since they must understand how their work interacts with that of other tradesmen.