City sustainability staff on Oct. 8 presented four local building-code amendment options aimed at accelerating building electrification and energy efficiency during renovations and equipment replacements.

Andrea Chow, sustainability analyst for the City of San Mateo, and Taylor Taylor, a TRC consultant working with Peninsula Clean Energy, outlined four options: mandatory heat‑pump or equivalent efficiency measures when installing or replacing space cooling (separate single‑family and nonresidential versions); a FlexPath (or “lehi path”) requirement that major renovations meet a points target of efficiency and electrification measures; and an electric‑readiness requirement to add electrical circuits/conduits where gas appliances are being replaced or installed.

Why it matters: Buildings account for a large share of local greenhouse‑gas emissions; reach codes let cities adopt local standards that exceed baseline state requirements (Title 24, Part 6 and Part 11/CalGreen) provided the measures are cost‑effective. Staff said reach codes are a way to capture emissions reductions during the higher‑volume renovation cycle rather than waiting for new construction.

Key technical points and costs

- Option 1 (cooling upgrades for single‑family homes, townhouses and duplexes): At time of air‑conditioner replacement or addition, property owners would either install a heat pump (which can provide heating and cooling) or install an air conditioner plus a package of efficiency upgrades. Staff said heat pumps typically cost $1,000–$3,000 more than a like‑for‑like central air conditioner but that Peninsula Clean Energy (PCE) rebates (currently $1,500 for heat pump HVAC, $2,500 for heat pump water heaters, plus 0% loans up to $10,000 and additional income‑qualified incentives) and lower operating bills narrow or eliminate the upfront gap. Staff estimated this option could reduce roughly 400 metric tons CO2e per year by 2030 in San Mateo.

- Option 2 (nonresidential single‑zone rooftop systems): State code already requires heat pumps for systems 5 tons and under. The reach code would extend the heat‑pump requirement or require a heat‑recovery ventilator for single‑zone systems between 5 and 20 tons. Staff estimated a higher GHG effect for this option (about 1,800 metric tons CO2e per year) and said a recent cost‑effectiveness study was published for this measure.

- Option 3 (FlexPath for major residential renovations): For renovations that exceed a threshold (staff used 1,000 square feet as an initial example), projects would need to meet a target points score from a menu of measures (insulation, air sealing, electric appliances, heat‑pump water heaters, solar PV plus electric readiness). In a sample 1,000‑square‑foot, $500,000 renovation, staff showed a target score of 18 could be met by installing a heat‑pump space conditioner at an added cost of about $12,500 (roughly 2.5% of the project valuation) or by an efficiency package costing about $21,800 (4.5% of the project cost). Staff estimated a flex‑path adoption could reduce about 730 metric tons CO2e per year by 2030. Commissioners discussed threshold sizing (500, 750, 1,000 square feet) and target scores (examples shown at 12, 18 and 30 points) and urged a cautious, piloted approach.

- Option 4 (electric readiness for single‑family conversions/additions): When a renovation places new gas appliances within three feet of work on electrical systems, the reach code would require installation of dedicated circuits, conduit or reserved breaker space to make later electrification less costly. Staff estimated incremental electrical readiness costs of roughly $150–$1,000 per appliance and noted statutory exceptions (for example, if panel upgrades would be required by compliance).

Public comment and stakeholder viewpoints

Public commenters were mostly supportive. Robert (representing the SAMTO Climate Action Team) said the commission should adopt strong measures and specifically backed the FlexPath approach with a higher points target. John McKenna, chair of Menlo Park’s environmental commission (speaking as a private citizen), urged San Mateo to match or exceed nearby cities and noted that panel upgrades are often not required. Fernando Peña, representing the San Mateo County Association of Realtors, asked for clarity about Assembly Bill 130 (a state budget bill that places limits on local code changes) and urged caution on mandates; staff replied that the city’s general plan and climate strategy satisfy statutory exemptions cited in the bill. Wendy Cho, an online commenter and San Mateo renter, described electrifying her older home and urged adoption of the measures.

Commissioner feedback and next steps

Commissioners generally supported options 1, 2 and 4 and were more cautious about Option 3 (FlexPath), asking staff to pilot the approach and consider thresholds and target scores that balance ambition with feasibility. Commissioners suggested using square footage rather than dollar valuation as the covered‑project trigger, keeping the first threshold at about 1,000 square feet for a pilot and testing target scores between 12 and 18 (several commissioners opposed moving to an effectively mandatory‑electrification outcome implied by a very high target such as 30 points). Peninsula Clean Energy staff on the call said the $1,500 heat‑pump HVAC rebate will remain available and noted enhanced income‑qualified programs.

Staff said the city council is tentatively scheduled to consider reach‑code direction on Nov. 3 and reminded commissioners that local reach codes must be filed with and approved by the California Energy Commission before they can be enforced (the filing/approval step can take several months). No formal action was taken by the commission at this meeting; staff requested the commission’s feedback to inform a council recommendation.