Net Zero New Buildings and Homes

There are 44 commercial proposals in the 2022 Building and Fire Code and Denver Green Code Adoption Process. Five of these commercial energy proposals account for 90% of the potential carbon emissions reductions. If recommended by committee, these five proposals will do the most to bring the 2022 code down to the red dot towards the Denver Energy Code (DEC) Max Potential.

The carbon intensity shown above considers the projected decarbonization of Xcel Energy’s electricity grid. The blue trajectory line represents the path Denver needs to reach our net zero goals.

Two of the five highest impact proposals would require new commercial buildings to use efficient electric space and water heating systems. This moves buildings away from fossil gas and towards renewable heating and cooling. In Denver, 20% of our greenhouse gas emissions come from burning fossil gas. 97% of this gas is used for space heating and hot water heating in our homes and buildings. Xcel Energy’s electrical grid in Colorado is getting dramatically cleaner and will be at least 80% renewable by 2030. – which is during the lifetime of any space heating equipment replaced now. This makes electric heat pumps the option with the lowest greenhouse gas emissions available today. 

All-electric buildings are also healthier, more comfortable, and cost less to build and operate. 

• A study by Group 14 for Community Energy Inc found that new construction for an all-electric commercial building costs $18,100 less than mixed fuel new construction.
• An 80 unit all-electric multifamily building in Salt Lake City projected upfront costs estimated to be $133,434.32 cheaper than a mixed fuel build. Additional savings from rebates were expected to amount to $1,000 per unit, or $80,0000 total in additional savings.

US residents spend roughly 90% of their time indoors. Indoor pollution levels are largely unregulated and often worse than outdoor air quality. Indoor air pollution caused by natural gas contributes significantly to adverse health impacts, such as exacerbating asthma and. Heat pump technology transitions homes and buildings to clean, highly efficient, all-electric heat. 

Summary and Schedule of big 5 commercial proposals:

Register here for the IECC & Denver Green Code Energy Chapters Hearing Series.

• #P40 – C403.2 Partial Space Heating Electrification Commercial

• These requirements allow either air source or ground source heat pumps. The intention is to make this only apply to general purpose space heating systems and not to specialty systems.
• Committee Schedule:  Vote July 2022.

• #P38 – C404.10 Partial Water Heating Electrification Commercial

• This proposal requires an electric heat pump system service hot water in new buildings. The intention is to make this only apply to general purpose water heating systems and not to the specialty systems.
• Committee Schedule:  Vote July 2022.

• #6 – Calibrate Section C406 to Denver’s Goals

• This proposal calibrates the number of points in the additional energy efficiency credit requirements section to meet the performance goals in “Denver’s Net Zero Energy (NZE) New Buildings & Homes Implementation Plan.” It provides the maximum flexibility possible for projects using the prescriptive path since project teams will choose which credit options are the most effective and cost-effective.
• Committee Schedule:  Vote July 2022.

• #18 – Limit Modeling to Appendix G
  • This proposal reduces the compliance paths to just the prescriptive path in the IECC and the modeling approach in Appendix G from ASHRAE 90.1.  The modeling approach from Appendix G was chosen because this modeling methodology has received consistent development with each development cycle of ASHRAE Standard 90.1. This has enabled the modeling path to more fully incorporate enhancements to the prescriptive path and define modeling parameters and variables more clearly.
  • Committee Schedule:  Vote July 2022.
• #4 - Minimum Renewable Energy for Commercial 
  • This proposal requires commercial buildings to acquire a minimum percentage (20%) of their annual energy consumption from renewable energy (or to achieve an equivalent amount of performance from additional electrification, energy efficiency or an offsite renewable energy resource). 
  • Committee Schedule:  Vote July 2022.

Within the 2022 Building and Fire Code and Denver Green Code Adoption Process, three residential energy proposals account for approximately 81% of the carbon emissions intensity impact. If recommended by the committee, these three proposals will do the most to bring the 2022 code down to the red dot towards the Denver Energy Code (DEC) Max Potential.

The carbon intensity shown above takes into account the projected decarbonization of Xcel Energy’s electricity grid. The blue trajectory line represents the path Denver needs to maintain to achieve the goal of buildings designed as net zero energy codes by 2027 and performing as net zero energy by 2030. The residential national model codes have not made the same kind of progress in the last few code cycles, therefore, Denver’s residential code has more ground to make up than the commercial codes in order to meet Denver’s goals.

All-electric homes are healthier, more comfortable, and lower-cost to build and operate. Building an all-electric home costs $2,700-$5,300 less and all electric homes have 2-8% lower annual utility costs than mixed fuel homes according to an RMI study and a study by Group 14 for Community Energy Inc.

People living in the United States spend roughly 90% of their time indoors where pollution levels are largely unregulated and often worse than outdoor air quality. Indoor air pollution caused by natural gas contributes significantly to exacerbating asthma and triggering asthma attacks, as well as other adverse health impacts. We can transition our homes to clean, highly efficient, all-electric heat powered by renewable electricity through the use of heat pump technology.

Summary and Schedule of big 3 residential proposals:

Register here for the IECC & Denver Green Code Energy Chapters Hearing Series.

• #67 – R404.4  Minimum Renewables for Residential
  • This proposal requires residential buildings to acquire a minimum percentage (20%) of their annual energy consumption from renewable energy (or to achieve an equivalent amount of performance from Section R408.1 or from an offsite renewable energy resource).  
  • Committee Schedule:  Vote July 2022.
• #47 – Calibrate Section R408 to Denver’s Goals 
  • The 2019 Denver Code and 2021 edition of the IECC both adopted an additional package efficiency option for residential buildings.  This proposal goes a step further by converting the efficiency package options into an additional energy efficiency points-based system.  The credit-based system allows projects to select the most effective and appropriate measures to achieve the performance goal of the code.  This maximizes flexibility while still allowing the code to achieve higher levels of performance.
  • Committee Schedule:  Vote July 2022.
• #31 – Calibrate Section R406 to Denver’s Goals
  • This proposal aligns the performance path with the prescriptive path and calibrates the Energy Rating Index (ERI) target with Denver’s Net Zero Energy residential goals.
  • Committee Schedule:  Vote July 2022.

To advance sustainability, resiliency and a transition towards regenerative design, the Denver Green Code Committee will consider moving the following proposals from the voluntary Denver Green Code to base code. Register here for the Denver Green Code series of the code hearings.

Summary of proposals that could move from voluntary Denver Green Code to base code:

• IPC #67 - Mandatory Irrigation Controls
  • When an automatic irrigation system is used, a smart controller must be installed to sense soil moisture and consider weather data to adjust irrigation schedules.
• IBC #79a - Expanded Indoor Environmental Quality: Low VOC materials
  • This proposal regulates building materials in commercial buildings (IBC) to limit the amount of Volatile Organic Compounds (VOCs) in interior applied products.
• IRC #79b - Expanded Indoor Environmental Quality: Low VOC materials
  • This proposal regulates building materials in residential buildings (IRC) to limit the amount of Volatile Organic Compounds (VOCs) in interior applied products.
• IPC #P34.1 - Public Proposal by Western Resource Advocates - Water Budget
  • This proposal requires all new or renovated landscaping provide a landscape plan that demonstrates 10 gallons per square foot or less of potable water is used every year.
• IPC #P34.2 - Public Proposal by Western Resource Advocates - Sub metered Irrigated Landscape
  • Irrigated landscapes areas greater than 25,000 are required to have a master valve with flow sensors and/or landscape areas are to be sub-metered with equipment that can remotely measure and transmit water use data.
• IPC #P34.3 - Public Proposal by Western Resource Advocates - Max Flow Rates and Water Consumption
  • This proposal reduces the maximum flow rate for plumbing fixtures and fixture fittings such as showerheads, bathroom sink faucets, urinals, water closets, and kitchen sink faucets.
• IPC #P34.4 - Public Proposal by Western Resource Advocates - Clothes Washer and Dishwasher
  • This proposal requires clothes washers and dishwashers to meet water consumption requirements through ENERGY STAR or through maximum water factors. 

A new building or home that is highly energy-efficient and fully powered from on-site and/or off-site renewable energy. 

Guiding Principles:

• We will need incentives to support new construction and the community.
• As a whole community of buildings, we want to achieve this goal.  We will not achieve it in every individual building.
• There will be different solutions for different buildings: our goal is to write an implementation plan that requires a fair and consistent level of effort across building types, sectors, and neighborhoods.
• Stakeholders will help us figure out this path.

This means all new homes (by 2024) and new buildings (by 2027) will be:

1. Highly Energy Efficient
   • Highly energy-efficient buildings on site
   • Target Energy Use Intensity (EUI) for commercial buildings.  Target ERI for homes.
   • Buildings will have to perform as designed where practical for that building type.
   • Energy efficiency is the step that makes everything more cost-effective.
2. All Electric
   • Reduce greenhouse gas emissions through all-electric equipment in buildings. 
   • No more natural gas in our new buildings and homes.
3. Powered by Renewable Electricity
   • On-site or off-site renewables focused on additional production. 
   • REC’s (renewable attributes) need to be retired by the customer or the utility and not sold.
   • By 2050 the grid will be 100% renewable. Buildings are part of that equation.
4. Providers of Demand Flexibility for the Grid
   • Energy storage, grid integration, and flexibility to respond to grid signals.

When Denver achieves the goals of all new buildings and homes meeting Net Zero Energy (NZE) by 2030 and all building and homes meeting NZE by 2040, the impact of embodied carbon emissions grows exponentially. Denver’s Building Sector Embodied Carbon Emissions(PDF, 3MB) details the key findings and provides strategies for reducing embodied carbon and for policy development.

The City and County of Denver developed a comprehensive Net Zero Energy New Buildings and Homes Implementation Plan with the New Buildings Institute (NBI) and intensive stakeholder engagement. The Implementation Plan details goals, milestones, and targets achieve net zero energy in new buildings and homes. Support for the document creation was provided by the American Cities Climate Challenge.

NZE New Buildings & Homes Implementation Plan(PDF, 4MB)

The Implementation Plan is heavily based on Denver stakeholder input to ensure this plan is equitable, accessible, and achievable for all building types and stakeholders. The City and County of Denver hosted Stakeholder Meetings to ensure this Implementation Plan provides specific and achievable pathways to net-zero energy new buildings and homes. The Phase One meeting and an interim meeting were held in 2019 and a Phase Two meeting and a Public Input Meeting were held in October 2020. The meeting notes and presentations for each are available below. 

Phase 1 Meetings: Completed in October 2019

• Phase 1 - Commercial Meeting Notes(PDF, 342KB)
• Phase 1 - Residential Meeting Notes(PDF, 292KB)

Interim Dec Meeting: Building Policies & Strategies for Climate Task Force*

• Interim Dec Meeting - Commercial Meeting Notes(PDF, 90KB)
• Interim Dec Meeting - Residential Meeting Notes(PDF, 78KB)

Phase 2 Meetings: Completed in October 2020

• Phase 2 - Denver NZE Commercial Meeting
  • Presentation(PDF, 1MB)
  • Notes(PDF, 263KB)
• Phase 2 - Denver NZE Multifamily Meeting Presentation
  • Presentation(PDF, 1MB)
  • Notes(PDF, 254KB)
• Phase 2 - Denver NZE Residential Meeting Presentation
  • Presentation(PDF, 1MB)
  • Notes(PDF, 255KB)

Public Input Meeting: Completed in October 2020

• Public Input - Denver NZE Public Meeting Presentation(PDF, 2MB)

*If you need assistance reading these documents please contact us at energyprogram@denvergov.org.

Please contact energyprogram@denvergov.org if you would like to be added to our Net Zero Energy New Building newsletters.