Architect & GC coordination
3rdGen supports HVAC for remodels and major renovations where mechanical decisions should happen early enough to coordinate with framing, ceilings, finishes, equipment access, duct routing, and electrical work — for residential GCs, architects, and high-end homeowners.
Approach
Remodel HVAC is where comfort problems are created or solved. We integrate supply and return paths with new architecture, plan equipment locations that respect finishes, coordinate with builders and architects from design development, and size systems for the post-remodel envelope.
What's included
Our Field Projects
Process
01
Share location, timeline, plans if you have them, and what is not working today — or what your builder has scoped.
02
We use Manual J, S, and D where the project needs it to match equipment, ducts, and zoning to the actual house.
03
Design-build field work with your GC or architect around access, finishes, sequencing, and clean rough-in.
04
System startup, basic orientation, and documentation so you know how the new system is meant to run.
Related
Some high-end remodels use sophisticated multi-zone refrigerant systems. For VRF system details, see commercial VRF & multi-zone systems .
Common Questions
Heat Pumps
Yes. Whole-home gas-to-electric conversions are a core part of our work. We size heat pumps for calculated heating and cooling loads, plan electrical capacity, and coordinate distribution, not a same-size swap based on your old furnace label.
Modern cold-climate heat pumps perform well in Bay Area winters and summers when sized with Manual J and installed with proper distribution. Coastal microclimates and inland heat spikes are why we engineer each home, not assume one product fits all.
We are Mitsubishi Electric specialists and design around the best technology for your home — ducted, ductless, or mixed layouts sized with Manual J/S/D, not rule-of-thumb equipment swaps.
Load Calculations
Manual J is the ACCA standard for calculating heating and cooling loads room by room based on your home’s envelope, windows, orientation, and local climate — not square footage rules of thumb. We use it to size equipment and duct systems so your system performs in real Bay Area conditions.
Square-footage rules ignore insulation quality, window area, shading, air leakage, and how your home actually gains and loses heat. Oversized equipment short-cycles, wastes energy, and struggles with comfort and humidity. Manual J matches capacity to measured loads.
Manual S selects HVAC equipment that matches Manual J loads without oversizing. Manual D sizes and lays out duct systems for proper airflow and static pressure. Together with Manual J, they form the engineering backbone of our design-build installs.
Process
Yes. Permit, Title 24, and inspection coordination are part of our design-build scope, not a surprise add-on at the end. We retain load calc and equipment documentation your jurisdiction and rebate programs commonly require.
Our work is project-based — heat pump installations, full-system replacements, remodels, retrofits, new construction, and ADUs. If you are not sure whether your project fits, send us a message and we will help figure out the right path.
Tell us about your home. We’ll follow up with next steps and a design consultation.
