To achieve net negative, materials are sourced for lowest embodied and emitted carbon. Engineered lumber structure sequesters 35 tons of CO2 and reduces greenhouse emissions vs. alternative materials by 75 tons for a 110-ton total benefit. Heating and cooling energy from metered photovoltaic array (estimated at 40,000 KWh/hour/year) and hot water from direct solar. Transport and manufacturing CO2 reduced by on-site fabrication and low-energy construction methods. Robust insulation with carbon negative dense-pack cellulose reduces emissivity on supply and demand sides. Low impact concrete/CMU foundations and retaining walls further cut via green mix, long cure, CO2 injection, light weight, reduced cement, non-fossil fuel SCM and are offset by net negative output of other systems and materials.