Tuesday, January 25, 2005
Residential Electrical Design
As often happens, the construction plans (blueprints) for this particular house arrived, and there is no Electrical plan, what to do, the builder still wants a bid price from you for the job? We engineer it ourselves, usually to National Electrical Code minimum standards, adding receptacles, lighting fixtures, controls, switches, and other items like telephone jacks, cable tv jacks, etc., in accordance with National Electrical Code dictates. At this point, with little or no input from the builder and/or homeowner.
I have loaded a floor plan for a small house to the site for you to inspect. It will enable you to see the various symbols and such that demark the various and sundry electrical devices throughout the building. I have only shown one floor of the building, but you can get an idea from this one level, which has the most important room in the house from an Electrician’s standpoint, the cook’s workplace and usually the core of the home - the kitchen.
You will see also an electrical symbols schedule, which denotes the different electrical components on the blueprints (read: black on white). This is a plan I engineered myself, with receptacles, switches, lighting fixtures, etc., marked in their respective locations. The receptacles are laid out, according to NEC, with each one located in a code-compliant manner. Switches at the entry to each space, for example two switches at the back door, one to turn on a light fixture on the exterior, to light the stoop as you leave the building, the second switch to turn off the kitchen light. It is in this manner that the safety of the homeowner is protected, the idea being that you light your way from one space to another, turning lights on and off as you traverse the building.
I can use this plan for estimating the basic components of the Electrical system, but I still need the info from the plumber, for the items he is installing. As I mentioned previously, a dishwasher, hot water source, a hot tub, steam generator, garbage disposer? The HVAC contractor also has to ring in with the items in his work arena, the boiler or furnace, the air handler(s), condensing units, and, obviously, thermostat locations and connection of the entire system. The HVAC contractor puts in his equipment for the heating cooling plant, Electricians hook it all up electrically and make it a fully functional system. Once the components of the various systems are decided upon, with the culmination of this information, the contract bid is prepared and submitted to the Builder, or General Contractor.
Once the bid is reviewed and accepted by all parties involved, and the job is awarded to Old Harbor Electric, Inc., the work on the job site begins. The next thing we do, as the awarded Electrical Contractor, is set up a source for temporary electrical power, for the various tradesmen working on the project.
On Cape Cod, where we have a somewhat seasonal economy, the year rounders are growing in their numbers, making every season a little busier. The new home construction industry, is fueled by demand of people purchasing a piece of property on the ocean, or lakeside, with the intent to build new, or remodel. Then there are the newly monied folks, having inherited a summer home from their parents, who consequently have the wealth to refurbish the existing dwelling or tear down and construct a new home on the site. The trend being they are going for the larger, so-called trophy home, known around here as wearing your money on the outside of your pants!
It is this cycle which keeps us busy the year around, although it is definitely much busier in the Spring, when the summer people turn their attention to their vacation home. We are constantly working on remodeling jobs, as opposed to new homes these days, since the customer these days seem somewhat timid of new home construction, what with the costs going up and the stress of building new. But I go on sometimes..........
The home building process almost always involves a designer or an architect of some kind, maybe even the homeowner themselves, with ideas of their own, or a person that the homeowner’s hire. The end result of this early process is an understanding by the architect or designer, of the participant’s expectations in the design and function of their domicile.
Construction drawings, with the various spaces defined, the walls, window and door locations, fireplaces, wall cabinets, bathroom and kitchen appliances; and plumbing fixtures, are then finalized and printed. It is at this stage that the builder, excavation contractor, foundation crew, building framer, electrician, plumber, heating contractor, well driller, and every other tradesman imaginable gets the first peek at the project, in two dimensions, in the form of blue prints.
With some building plans, the electrical work is charted out for the electrician, with standard electrical symbols for the various electrical devices, designated on the floor plans for each space of each floor of the residence. The Electrical Engineer, hired by the design team, would perform this function. The items included would be the receptacles, switches, dimmers, fan controls, timers, heating controls, and lighting fixture locations, the latter being delineated by a letter-based lighting fixture schedule that corresponds with the blueprint. There might also be yard lighting, a post lantern for instance, a spot light or flood lighting for the back yard, even a water feature, or fountain.
The Electrician, gathering information from the floor plans and fixture schedule, must verify that the electrical design, including receptacle, switch and fixture locations, complies to National Electric Code and applicable Building Codes, at both the State and Town levels. Therefore, while trying to stay within those bounds, the electrical installation must also pass inspection when completed, regardless.
If the Electrician is also an alarm installer, there would be specifications for the system, for fire and burglary, even for low temperature warning systems for the unoccupied - but nonetheless heated - summer home.
Telephone systems, Cable Television (CATV), Data Terminals, or Structured or Premises Wiring System, for networking computers and providing internet access, or surveillance cameras for checking security from afar, raising or lowering the thermostat, via telephone or email command.
The Electrician must also be in the loop with the plumber, his installation criteria and the crossover of electrical work; that is anything that the electrician has to do for a plumbing feature to function in the home, such as a Whirlpool Bath, a Hot Tub, a Steam Room, Electric Hot Water, an instant Hot Water Heater, a loop pump to recirculate hot water, a dishwasher, or a garbage disposer, the water pump, a septic lift pump or other waste system wiring requirement.
Besides the plumber, there is the Heating Ventilating and Air Conditioning (HVAC) contractor and the needs of the various climate control systems, including the boiler, or hot water source, the condensers for the Air Conditioning, the air handlers that distribute the conditioned air. Not to mention all the bells and whistles.
Pricing all of the Electrical work would then ensue, by the Electrician, and a cost would be rendered to the builder for consideration as a competitive bid for the scope of the work involved. Having a set of Electrical plans to price from is one method that is used by Architects, Builders, and Remodeling Contractors, this occurs in roughly 25% of the residential electrical work my company does. The rest, who does the Electrical Engineering if there is no Electrical Engineer on the staff, if there were no electrical plans?
Remember what I said earlier, that the Electrician must be sure that the electrical installation passes National Electrical Code, at both State and Local levels. Who’s the engineer in 75% of the homes built across America? That unsung hero, big surprise here -The Electrician!
01:00 Permalink | Comments (0) | Email this


The comments are closed.