Mechanical Systems for Bay Area Homes and Buildings

Residential heating and cooling, plus commercial mechanical systems—from design and coordination through installation.

Residential Heating & Cooling Commercial Building Systems

Berkeley-based since 2015

HVAC design and installation for Bay Area homes and buildings

3rdGen designs and installs heating, cooling and ventilation from our office in Berkeley. On the residential side, that means heat pump installation, full-system replacements, and HVAC for remodels, ADUs and new construction, each sized with a Manual J load calculation before equipment is chosen. Homeowners rate us 5.0 stars across 207 Google reviews.

On the commercial side, we work with general contractors, architects and engineers on plan-spec mechanical, design-build, VRF, tenant improvements and multifamily HVAC. Both divisions hold California C-20 license 1086898 and serve the East Bay, Marin, San Francisco and the Tri-Valley.

Service areas include San Francisco, Mill Valley, Berkeley, Oakland, Alameda, Lafayette, Moraga, Orinda, Walnut Creek, Alamo, Danville, Pleasanton, San Ramon, and more Bay Area cities.

Residential Services

Heat Pump Installation & All-Electric Conversions Bay Area heat pump installation, furnace-to-heat-pump conversions, and gas-to-electric upgrades — ducted, ductless, and full-system projects sized with Manual J-informed design. Full-System HVAC Replacement Complete residential HVAC replacement when sizing, ductwork, comfort correction, zoning, or electrification matter — not emergency or same-size equipment swaps. HVAC for Remodels Residential HVAC planning and installation for Bay Area remodels — heat pumps, ductwork, equipment placement, Manual J/S/D, and coordination with your builder or architect. HVAC for New Construction HVAC planning for new homes and custom residential projects — Manual J/S/D support, equipment selection, duct design, heat pump systems, and builder or architect coordination before rough-in is locked in. ADU HVAC HVAC for ADUs, garage conversions, and additions where comfort, code, equipment placement, and space constraints matter — often compact heat pump or ductless solutions. Manual J / S / D Load Calculations In-house Manual J, Manual S, and Manual D support so equipment sizing, system selection, and duct design are based on the actual home — not guesswork.

Mechanical Services

Plan-Spec Mechanical Execute engineered mechanical scope from bid and submittals through installation, startup, and closeout when the engineer-of-record holds design responsibility. Design-Build & Design-Assist Design-assist during development and design-build with licensed mechanical engineering partners when the project needs a combined design and construction path. VRF & Multi-Zone Systems Complex commercial and residential VRF systems planned around zoning, equipment placement, refrigerant routing, access, startup, and long-term serviceability. Controls-Ready Mechanical Mechanical systems prepared for BAS or controls integration through BACnet-capable equipment coordination and communication-ready infrastructure. 3rdGen does not perform BAS programming. High-End Residential HVAC Full-system retrofits, remodels, new construction, heat pump conversions, and design-build HVAC for homes where comfort, layout, and finish details matter. Multifamily HVAC Repeatable HVAC systems for multifamily and mixed-use projects, coordinated around unit layouts, ventilation needs, equipment access, and construction sequencing.

Load Calculations & Design Input In-house Manual J, Manual S, and Manual D support for residential scopes, with practical design input before equipment and duct decisions are locked in.