How Building Upgrades Interact With Each Other

Nick Natsoulis
4 Minutes Read
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    Building upgrades are often approached as individual projects depending on the specific systems involved - HVAC, electrical devices, plumbing and fire protection are some examples. However, building systems interact with each other during actual operation, and this must be considered if you want to achieve the best results. If you ignore the interaction between building systems, two upgrades may interfere with each other, decreasing the performance of both.

    Since each building has specific conditions, a professional inspection is highly recommended to identify the best building upgrades. Also consider that NYC laws often require mandatory upgrades, such as sprinkler systems for buildings covered by Local Law 26, and energy-efficient lighting in buildings covered by Local Law 88.

    This article describes some connections between building systems that are commonly found when planning building upgrades. Each building is unique and there is no general approach that can be used for all, but the following are common scenarios in NYC projects.

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    Plumbing Installations and Domestic Hot Water Systems

    Water leaks and clogging are common issues in older plumbing fixtures, and both are detrimental for overall building performance.

    • When you add the total water loss due to leaks in a large building, the annual impact on municipal water bills can be significant.
    • Clogging results in poor flow, and the effect can be worsened in upper floors due to pressure loss. Low flow can even be dangerous in the case of hot water showers, since water tends to overheat.

    Fixing leakage reduces water consumption, while fixing clogged fixtures increases it. However, when you perform an overall plumbing upgrade, you will most likely get a reduction in overall water consumption. This is especially true if you specify water-saving fixtures for the upgrade.

    The capacity of your domestic hot water (DHW) system is strongly determined by water consumption. As a result, you can expect a load reduction on your water heating equipment after a large-scale plumbing upgrade.

    • If you are considering a DHW upgrade, checking your plumbing system first is strongly recommended.
    • Massive reductions in water use are viable in old buildings with a lot of leaky plumbing fixtures - it may be possible to specify a lower capacity for the new water heating equipment.
    • Having a more efficient DHW system is great, but the savings are even higher if you combine efficiency with capacity optimization.

    Building Envelope, Lighting Fixtures and HVAC

    The main purpose of an HVAC system is to keep indoor air conditions suitable for human occupancy. This is accomplished by controlling temperature and humidity, while establishing a continuous supply of outdoor air. The load on heating and cooling equipment is due to both internal and external sources.

    • Summer heat gain and winter heat loss through the walls and ceilings are unavoidable, although they can be minimized with a high-performance building envelope.
    • There are also internal heat sources in buildings, including humans and many types of equipment.

    Lighting fixtures introduce a significant amount of heat. The effect of one fixture may not be much, but consider that large buildings have thousands of them. LED lighting fixtures can reduce the heat output significantly when they replace older types of lighting.

    • Heat output reductions of up to 50% are viable when upgrading from fluorescent to LED lighting, and reductions of over 80% are possible when upgrading from incandescent or halogen bulbs.
    • For example, if you replace a 128W fluorescent fixture with a 50W LED fixture, 78W of heat output are removed. In a building with 1,000 of these fixtures the total is 78 kW.

    Specifying a high-performance building envelope for a new building is easier than upgrading an existing property, but there are some viable measures that can be deployed without taking apart the existing walls. Insulation and air-tightness improvements can provide a notable reduction in heating and cooling expenses, without being overly expensive themselves.

    Similar to the case of DHW systems and plumbing upgrades, you can expect a reduction of HVAC expenses after building envelope improvements, and a slight reduction of air conditioning expenses after a lighting upgrade. Get an assessment of your lighting system and building envelope before major HVAC upgrades, since there may be opportunities to reduce the nameplate capacity of the new equipment!

    Space Heating and Domestic Hot Water

    Some buildings use combined systems for space heating and domestic hot water, and this represents a major opportunity for energy efficiency. Operation can be very wasteful during the summer, when some boilers run at full capacity only to meet the DHW load; winter efficiency tends to be higher because both heat outputs are used.

    In cases where space heating and DHW are provided with an old and inefficient boiler, a drastic reduction in operating costs may be possible by replacing the existing unit with two separate systems of higher efficiency.

    Proposing a general solution is not possible because each building has unique heating demands. Therefore, a professional assessment is highly recommended to get the best results for each project.

    Lighting Fixtures and Sprinkler Systems

    Although lighting fixtures and sprinkler systems do not interact, they have one thing in common in New York City: both systems are covered by Local Laws that require mandatory upgrades. Keep in mind that the requirement is not for all buildings, only for those meeting certain conditions described in the corresponding laws.

    • Local Law 26 requires automatic sprinkler systems by July 1, 2019.
    • Local Law 88 requires lighting upgrades that meet the NYC Energy Conservation Code by January 1, 2025.

    If you have a building covered by both LL26 and LL88, scheduling both projects at once can be a smart approach. Lighting upgrades and sprinkler installation both involve taking apart portions of the ceiling, and the disruption is less if you only have to dismount the ceiling once.


    Buildings are complex systems with many interacting elements. If you plan to upgrade one piece of equipment or building feature, it is important to analyze how the rest will be affected. Also keep in mind that each building has specific conditions and requirements, and this can only be addressed with a customized approach - the first step for any building upgrade should be a professional assessment.


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    Tags : new york NYC local laws Energy Efficiency Building Upgrades

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