Column - Plans & Specifications

On the whole, my business interests have shifted from bidding projects that have plans and specifications, or “plan/spec”, to more design-build and customer-direct stuff. However, there are always projects coming down the pike that fit the plan/spec mold, that are worthwhile for me to bid, for whatever reasons. That being said, I have to keep up on the rules that govern these types of projects, and I find that I’m in a state of continuous learning, even after many years of doing this.

I came across a set of plans and specifications recently, for a project that really didn’t fit my business model, so I passed on it. However, the contract documents, i.e. plans and written specifications, got me thinking about how all of this is put together. I really hadn’t been concerned with anything more than the mechanical plans and specs, and maybe the electrical plans as well, on projects that I have been involved with. But there’s so much more to it than that. I thought to myself, maybe it’s time to pull together all of this into a two-part column, explaining in simple terms and serving as a point-of-reference, the basics of a plan/spec project. So that’s what I did! Part one, presented here, covers the plans, and part two, coming next month, will cover the written specification.

Although this writing is not specific to the area of building automation, it doesn’t hurt for those of us in the construction industry working in our particular disciplines to know more about the entire process. A “big picture” view gives a better understanding of how we fit in to the project.

General “G”

The cover page of the plans! This is where you’ll find the “table of contents” (drawing index), as well as other “general” information about the project, such as location, area map, general notes and symbols, and so on. There may be more than a single sheet to cover this information, as need be, which may also include other information specific to the project, municipality, code compliance, life safety, etc.

Civil “C”

This is admittedly one set of plans that I skim right over. So I’ll try to explain in laymen’s terms and keep it short and to the point. This is where you’ll find the site information, such as, existing conditions, utility plans, sanitary and stormwater system plans, site grading plans, etc. You may also find included in this section, parking lot plans, and even landscaping plans. There may be some general notes included, but for the most part, this is all work performed outside of my chosen discipline.

Structural “S”

These plans cover the general framework of the building, the “skeleton”, so to speak. The ironworkers trade is responsible for the work included in these sheets. The structural steel that supports the flooring and skin of the building consists mainly of vertical columns and horizontal beams. This is what you see after the building first comes out of the ground. An “erector set” of vertical and horizontal metal segments.

The mechanical engineer responsible for laying out the heating and air conditioning systems pays special attention to these drawings, for in order to locate equipment (such as rooftop units and large interior equipment) and ductwork (especially large riser ducts), there needs to be coordination between the structural steel plans and the mechanical plans. Just goes to show how there’s a connection from one set of plans to another, and ultimately between all plans and all disciplines.

Architectural “A”

This set of plans typically represents the “bulk” of the drawing set. Case in point: the plans for the project that I’m referencing has a total of 48 drawings. Compare that with the “S” drawings (12), the “M” drawings (8), and the “E” drawings (16).

So here is where you find the general foundation plans, framing, wall sections, interior elevations, etc. Millwork sections and details, doors and hardware, windows…the list goes on. You’ll also find the reflected ceiling plans here, which are important for the mechanical design engineer, as to where the supply diffusers and return grilles are to be located. Another good example of the need for coordination between and among all trades and disciplines.

Fire Protection “FP”

The fire protection contractor is responsible for the work included in this set of plans. This is the indoor sprinkler system. Those nodes that you see up in the ceiling tiles…the ones that you see in the movies where someone gets the idea to put a flame to one of them…yeah, you get the idea! Mechanical and electrical contractors need to coordinate with the fire protection plans so that they can run their ductwork, pipe, and conduit to avoid the fire protection pipework and splinkler heads.

Plumbing “P”

The second of three trades that deal in pipe (the third being mechanical). This includes all fixtures and equipment that go along with it. Sinks and toilets, domestic hot water heaters, and so on. Sanitary waste piping and venting as well. Again, coordination between trades is an issue that must be dealt with, for all trades have to live in harmony, with no conflicts and no altercations. Seriously though, the other trades, mechanical in particular, with their large ductwork and big heavy equipment, need to work together so that, in the end, everything fits and is serviceable.

Mechanical “M”

Building Automation falls under this discipline, but there is so much more than that! Starting with the equipment…air handlers and rooftop units, boilers and chillers, pumps and fans, and all of that unitary equipment as well. Connect it all together with ductwork and piping, and you have yourself a mechanical system! Of course controls plays a big part in getting everything working properly, and Building Automation Systems (BAS) have become the norm in pulling all of this equipment together and operating at a fully functional and optimal level. At least that’s the idea!

Electrical “E”

The final set of drawings, at least for the project that I’m looking at. These drawings will include everything electrical, with the exception of the Building Automation Systems and maybe some other low-voltage systems such as security and CCTV, which may be handled by another discipline altogether. The project electrical contractor will handle the scope of work included in these plans. Panel schedules and power diagrams, lighting plans and panel locations. Other miscellaneous systems as well, from 120-volt receptacle wiring, to 460-volt three phase power wiring (the big stuff!).

Tip of the Month: Be mindful of the other trades on any given project, and of the interplay between them. Just because you’re in the mechanical discipline does not mean that you only need to review the “M” drawings. This holds true across the board, however of course there are certain disciplines that impact your trade more than others. The “C” drawings may not have much effect on the temperature control drawings embedded within the “M” drawings, for instance. Nonetheless, it pays to know that there is more to it than your particular trade, and to know that it takes all trades working together to reach the ultimate goal.

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