2606 Vandam Passive House Report

This report evaluates the energy performance, thermal comfort, and long-term durability of the proposed 2606 Vandam retrofit across five design variants. The PHPP results show that the current high-performance path can reach Passive House levels of performance.

The following sections summarize the energy model, envelope, window, and mechanical assumptions that support that conclusion. Generated model data comes from the current Vandam PHPP workbook; narrative sections are being migrated from the legacy Hugo report.

The model uses the drawings and geometry received April 28, 2026, including the building massing and local shading context. PHI results use treated floor area (TFA); Phius-oriented comparisons use interior conditioned floor area (iCFA).

The report compares the existing code-minimum baseline, envelope and HVAC improvement steps, and the EnerPHit pathways. The current PHPP scrape selects enerphit_by_demand as the recommended variant; the legacy Hugo report highlighted EnerPHit by Component, so that difference remains a value-parity check before cutover.

Site energy is the annual energy consumed at the building. Source energy accounts for upstream generation and delivery losses. CO2e is shown as an informational indicator only; it is not a Passive House certification metric.

The envelope recommendations are driven by PHPP performance, but the real design concern is control-layer continuity: thermal continuity, airtightness, vapor control, and constructable transitions at existing foundations, roofs, and window openings.

The target airtightness for the Passive House path is less than 0.8 ACH50. NYC Energy Code 2025 / Zone 4(A) is materially looser at 3.0 ACH50, so airtightness is one of the highest leverage measures for comfort, durability, and reduced heating demand.

Where existing conditions make perfect air sealing difficult, the report keeps Aerobarrier as a backup strategy rather than the primary air barrier. The primary recommendation is still to build continuous, inspectable air-control layers at each assembly.

The legacy report split each assembly into a separate Hugo page. The new report collapses those recommendations into one section so the design team can compare the wall, roof, floor, and crawlspace conditions together.

These recommendations are based on Flixo Energy v8.2 two-dimensional heat-flow analysis and should be coordinated with the architect and structural engineer. Structural member sizing and spacing remain by others; sizing shown here is tied to target insulation levels.

The Passive House window target is driven by both energy demand and localized thermal comfort. For this climate, the legacy report used an installed target of U-0.18 Btu/hr-ft2-F or better, compared with the NYC Energy Code 2025 / Zone 4(A) minimum window U-value of 0.35 Btu/hr-ft2-F.

The south facade has useful winter gain, but that gain becomes a summer comfort risk if it is not controlled. Robust user-operable shades are recommended at all south-facing glazing, and additional exterior or landscape shading should be considered where lower level or east/west glazing is exposed.

Candidate high-performance window suppliers from the legacy report include Intus, Ikon, Alpen, Wythe, Zola, SmartWin, and Okonoplast. High-performance skylights should be reviewed against Fakro, Lamilux, or equivalent products. All quotes and shop drawings should be submitted to BLDGTYP before ordering.

The ventilation strategy should be a dedicated supply-transfer-extract system, independent from heating and cooling distribution. Supply air should serve bedrooms and living spaces; extract air should come from bathrooms, kitchens, and storage or utility spaces. Door undercuts or transfer grilles are required between supply and extract zones.

The legacy report recommended a high-performance H/ERV with better than 75% heat recovery, with the Zehnder America ComfoAir Q600-ERV as the basis of design. The vendor should also balance and commission the system after installation.

Because the enclosure should have low cooling loads, dehumidification can become separate from thermostat control. Whole-house dehumidification should be planned for, and whole-house humidification should be considered if winter intermittent occupancy is likely.

Kitchen exhaust and other appliance venting should stay as low-flow and all-electric as practical. Dedicated makeup air is a backup condition, not the preferred baseline, because it adds envelope penetrations, commissioning risk, and a heating/cooling penalty.

Appendix content connects report claims back to PHPP rows, source PDFs, and model assumptions without making the main client narrative too dense.

Passive House certification is used here as a reference level for a durable, high-performance retrofit. PHI EnerPHit and Low Energy Building pathways remain relevant to this project; Phius retrofit certification is not the recommended certification route for this scope.

Operational CO2e is informational. The legacy report benchmarked annual building emissions against a 4-person occupancy and NYC eGRID 2020 factors, but CO2e is not a PHI EnerPHit certification metric.