Decarbonization Planning Guide

Load reduction is the process of minimizing a building’s heating and hot water loads before you electrify your heating equipment. Load reduction is crucial for any building decarbonization project for several reasons: 

• High building heating loads require large systems to keep the building comfortable in cold weather. This might result in inefficient performance outside of the coldest days. The required equipment might be so large that the building’s existing space and infrastructure might not support it. 
• Load reduction allows downsizing the heating equipment. Typically, when comparing costs, electrification measures can be more than twice as expensive as combustion-based equipment. When viewed as a whole, an optimized slate of load reduction measures and heating system replacement often has both a lower capital cost and life-cycle cost than electrifying heating equipment on its own. 
• Load reduction decreases peak electrical load impact. Often, in an electrified building, peak demand shifts from summer to winter because of peak heating needs. This can strain the grid, increase demand for electricity, and shift the impact of monthly utility charges from usage to demand.   

When viewed independently, load reduction measures traditionally have had long payback periods and limited benefit from increased performance beyond code compliant levels. When electrification becomes the end goal, a holistic assessment is necessary to account for all saving benefits from smaller heat pump equipment size, reduced infrastructure needs, and decreased peak demand charges. 

Conventional strategies vs. Advanced measures 

Load reduction is viewed in two categories: conventional strategies and advanced measures. 

Future proofing considerations 

Successfully decarbonizing a building requires a forward-thinking approach. By making key decisions earlier than you might think you needed to, you can facilitate upgrades down the road and avoid stranding assets. This not only lowers the cost of decarbonization, but makes the building more resilient to extreme weather and other emergencies. Examples of future-proofing include:  

• Depending on the size of the building, consider infiltration testing both before and after air sealing to support optimal HVAC system sizing. Significant improvements to a building’s insulation system can improve overall resilience and limit impacts of extreme weather conditions.  
• If your goals include a new HVAC system or rooftop solar, consider conducting a structural inspection before upgrading roof insulation to see if the roof can support large HVAC equipment or solar panels. If the structure needs upgrades, complete them before or at the same time as the insulation to avoid removing new insulation later for structural upgrades.  
• When upgrading a hot water system with a heat pump, implement load reduction measures beforehand. After installation, consider conducting a stress test on the lower water temperature to see if it meets the building’s heating load, and whether the hot water distribution system needs any upgrades.