Quincy’s Triple-Decker Revolution: How 2025 Building Codes Are Transforming Shared Cooling Systems in Historic Multi-Family Properties

The iconic triple-decker buildings that define neighborhoods throughout Massachusetts are experiencing a revolutionary transformation in 2025. These multifamily houses known as triple-deckers, or sometimes “three-deckers,” have attracted attention as part of Massachusetts’ attempts to slash emissions from building sources, which are responsible for about 27% of the state’s greenhouse gases. With some 17,000 remaining, though many still sport drafty windows, oil-burning heating systems, and little or no insulation, these historic structures are now at the forefront of innovative HVAC solutions driven by Massachusetts’ progressive building codes.

Understanding the 2025 Massachusetts Building Code Changes

On January 1, 2025, the 10th Edition of the MA Building Code (780 CMR) came into full effect. Any permit applications submitted on or after January 1, 2025 must comply with the 10th Edition of the MA Building Code. These new regulations have significant implications for multi-family properties, particularly the historic triple-deckers that characterize neighborhoods like Quincy.

The updated codes emphasize energy efficiency and electrification readiness. ERV or HRV will now be required. Bath fans no longer meet the requirement for whole-house mechanical ventilation. For multi-family buildings, those with central heating and cooling are considered commercial buildings, subjecting them to more stringent requirements under the commercial building codes.

The Challenge of Triple-Decker HVAC Systems

Constructed in the late 1800s and into the 1930s, triple-deckers were designed to provide rental housing to the waves of immigrants coming into the region. Each building had three roughly identical units — one per floor — as well as a flat roof and windows on all four sides. This unique architecture presents both challenges and opportunities for modern HVAC installations.

Traditional approaches to multi-family HVAC fall into two categories: centralized and decentralized systems. Centralized HVAC systems are supported from a central location such as a mechanical room in the basement of the building. Centralized systems tend to run more efficiently than decentralized HVAC systems. However, installation costs run higher, which make this ideal for a larger property that would be considered mid-rise or high-rise.

Innovative Shared Cooling Solutions for Triple-Deckers

The 2025 building codes are driving innovative shared cooling system installations that balance efficiency, cost-effectiveness, and tenant comfort. Multi-family properties benefit from modular or scalable HVAC systems due to their inherent flexibility. Rather than forcing property managers to overhaul the entire system when new requirements arise, modular setups allow incremental upgrades. If an apartment building needs more cooling power or better zoning to accommodate additional tenants or different usage patterns, components can be added without a complete tear-out of the existing infrastructure.

One particularly promising approach involves shared systems that combine ventilation and cooling functions. A multi family project used a shared oversized HRV feeding a ducted air handler for a number of units. This way the shared unit was not only providing fresh air to every unit (which is needed if you make the place sealed) but also sufficient airflow to handle cooling loads. Something like a 1500CFM HRV+5 ton air handler is probably in the ballpark for 16 units.

Smart Technology Integration

Modern multi-family HVAC systems are increasingly incorporating smart technology to optimize performance and reduce costs. If a building’s ventilation component is not functioning optimally, the system can send data-driven notifications to property managers, preventing major breakdowns and saving money on emergency repairs. These devices also allow for personalized cooling and heating schedules, putting control back into the hands of building owners and tenants alike. By embracing advanced IoT products, property managers gain a competitive advantage: energy usage can be fine-tuned according to occupancy patterns, significantly cutting back on unnecessary consumption.

Professional Installation and Service Requirements

Given the complexity of these new shared cooling systems and the stringent requirements of the 2025 building codes, professional installation and ongoing service are crucial. Property owners in Quincy seeking reliable ac installation quincy services need contractors who understand both the unique challenges of triple-decker buildings and the latest code requirements.

At Dempsey Energy, we understand that your home’s comfort depends on reliable North Attleboro HVAC, plumbing, electrical and energy systems. For over 30 years, families across Massachusetts have trusted us to keep their homes running efficiently and comfortably. With fast, same-day repairs, fully stocked trucks, and 24/7 emergency services, we’re here when you need us most—ensuring your home stays safe, comfortable, and stress-free.

Cost Considerations and Benefits

While shared cooling systems may require higher upfront investment, they offer significant long-term benefits. The distributed heating, cooling and domestic hot water components are arguably easier to service, and lower in cost to maintain by less skilled personnel than central systems. Problems with systems are limited to individual units rather than many units or entire buildings. Distributed systems are also less expensive to install in many regions.

The 2025 building codes also create opportunities for financial incentives. Take advantage of rebates and incentives when you upgrade to eco-friendly systems, making your investment in green energy even more affordable.

Indoor Air Quality and Health Benefits

The new shared cooling systems mandated by 2025 codes prioritize indoor air quality alongside energy efficiency. The importance of health and wellness makes for a stronger focus on indoor air quality (IAQ). More people stay at home—whether they do remote work or stay in on a Friday night—people need to know that their home’s air is safe to breathe. HVAC systems have been created with IAQ in mind, which incorporate: UV-C light technology helps eliminate disease-causing airborne microorganisms.

Looking Forward

As Quincy’s triple-deckers undergo this HVAC revolution, property owners must balance historical preservation with modern efficiency requirements. The shared cooling systems emerging from 2025 building codes represent a significant step forward in creating comfortable, efficient, and sustainable multi-family housing.

Dempsey Energy, a family-operated company, began in 1992. Since 2001, we’ve provided HVAC and plumbing services. We value community and family, aiming for trust and transparency. For property owners navigating these new requirements, working with experienced local contractors who understand both the unique challenges of triple-decker buildings and the evolving regulatory landscape is essential for successful implementation of these innovative shared cooling solutions.