New York City is filled with historic buildings, many of them dating back to the pre-war era. However, although antique properties are highly valued in the real estate sector, they involve engineering challenges not present in more recent buildings. Most electrical issues in old buildings come from the fact that their circuits and electrical protections were not calculated for the needs of the modern world.
The electrical infrastructure in older buildings may not be suitable for the intended occupancy, especially if modern equipment and appliances will be used. There are two main scenarios where an electrical infrastructure upgrade may be necessary.
When electrical wiring has deteriorated to a point where it can no longer be used safely.
When electrical wiring is in good condition, but does not have enough capacity for the projected load.
To determine if a property requires an electrical upgrade, first it is necessary to assess existing capacity, to then compare it with the projected load. Getting in touch with aconsultant or engineering firm is highly recommended to determine whether you need an electrical upgrade, and optimize its cost in case it is necessary.
Copper and other conductor materials can last for decades, but the same cannot be said of wiring insulation. New conductors have flexible insulation, but in older installations it may become brittle and peel off even with slight movements. This represents an unacceptable risk, given that exposed wiring sections are potential points where a line-to-ground fault may occur; uninsulated live conductors represent a serious risk of fire and electric shock.
However, it is important to ensure that the new wiring is suitable for the expected load; avoid replacing the old wiring with new conductors of the same capacity, or the installation may fall short even after the upgrade.
Hire an engineering consulting company to calculate the electrical load expected after occupancy, and ask them to suggest energy efficiency measures that reduce it.
After a series of energy efficiency measures have been proposed, wiring and electrical protection devices can be sized. If you skip the energy efficiency step, you will assume unnecessary expenses by upgrading to an oversized installation.
Consider that there may be different rules to follow for residential and commercial properties. There is generally more freedom in commercial buildings, while most multi-dwelling residential buildings are housing cooperatives, where alterations normally require approval from the cooperative board.
Also keep in mind that many historic buildings in New York City are protected by a Landmarks Preservation Law, and there may be a limit to how much you can modify the current infrastructure. This is rarely an issue in residential properties, but may limit energy-intensive businesses. For example, starting a business that uses plenty of refrigeration equipment may not be possible in a landmark building where the interior alterations allowed are limited.
How Energy Efficiency Can Help You Avoid Wiring Upgrades
If old electrical installations in a residential or commercial property must be upgraded, the procedure is not as simple as installing new conductors of the required capacity. Electrical codes have changed drastically over time, and the new installation will be required to meet the current version of the NYC Electrical Code, as well as the newer Energy Conservation Code. In other words, you may have to assume additional costs for code compliance.
In these cases, energy efficiency measures provide a dual benefit. Other than reducing your electricity bills, energy-efficient equipment can help you avoid expensive upgrades by keeping total load below existing capacity. Keep in mind, however, that this only applies if the wiring is in good condition.
LED lighting is a very effective energy-efficiency measure, since it can reduce lighting power by more than 80%. You should also look for efficient air-conditioning equipment; for example, a new ductless mini-split system may consume less than 50% of the energy required by a window-type air conditioner to deliver a specified cooling output.
One of the best ways to achieve energy efficiency is purchasing ENERGY STAR equipment, and you may even get some rebates from Consolidated Edison.
Whenever you must choose between 110V and 220V equipment, go for the 220V version, since current consumption is reduced by half. Remember that wiring capacity is based on current, not voltage.
Older buildings in NYC typically have steam radiators, and in some cases they are converted to use hot water by property management companies. Electricity-based heating is not recommended, unless you are upgrading from resistance heaters to heat pumps. Actually, older buildings tend to have oversized heating systems, since building codes in the early 19th century required heating calculations to be performed assuming open windows.
NYC Electrical Code and Energy Conservation Code Compliance
If there is no option but to upgrade the wiring in a commercial or residential property, the new installation must be designed and installed according to the NYC Electrical Code, which is based on the National Electrical Code (NFPA 70), but with additional requirements that are specific to New York City. The following code sections apply for a wiring upgrade:
Chapter 2 - Wiring and Protection
Chapter 3 - Wiring Methods and Materials
The 2016 NYC Energy Conservation Code also applies for electrical alterations. Although the code does not force upgrades on existing properties that were compliant at the time of their construction, it becomes mandatory if any modifications are carried out, which is the case when the existing electrical installation is insufficient. Alterations in residential buildings are covered in Chapter R5, while alterations in commercial buildings are addressed in Chapter C5.
Work with qualified professionals to make sure your project meets applicable codes and follows the permitting process required by the NYC Department of Buildings. Ideally, the energy consumption assessment should be carried out by an engineer who is a Registered Design Professional (RDP), and if upgrades are necessary you should work with NYC Licensed Electricians.