Walk through a green building and its climate measures seem obvious: solar panels on the roof, a cistern in the yard, a battery in the mechanical room. In Seattle, those are the ones that do the least.
The city’s water arrives by gravity from two protected watersheds, and its power comes from a hydro-dominant grid that Seattle City Light has run greenhouse-gas neutral since 2005. Against a commons that clean, rooftop solar and rainwater used as supply are close to carbon-neutral, possibly a small net cost. What carries the carbon is less visible: keeping the existing house, replacing gas with heat pumps, the envelope and lower-carbon materials.
Studio Viridian’s position memo, The Right Scale, sorts every measure available on its Seattle infill lots by the carbon it avoids per dollar.
Carbon value per dollar in Seattle: the visible systems sit at the bottom
Thirteen measures in the memo’s rank order. Bar length is the memo’s rating, a judgment, not a measured quantity.
Ranks within two or three places of each other are not meaningfully different. Only the heat pump (about $250 a ton of CO2e), measured weatherization (about $330) and salvage (about $2,900) carry a cost per ton from the companion papers. The ranking inverts in most of the world. Source: The Right Scale, § 05.
That last point is the memo’s central finding. Carbon value is a property of what a system displaces, in the place where it is installed, not a property of the technology.
Same hardware, different places
A solar panel carries its carbon up front, roughly 30 to 50 grams of CO2e for every kilowatt-hour it delivers, and Seattle’s gray skies spread that cost over fewer hours. A kilowatt of panel yields about 1,000 to 1,100 kilowatt-hours a year here, against 1,700 to 1,800 in Phoenix. The grid it displaces here runs about 4 to 20 grams per kilowatt-hour. In Delhi or Warsaw the grid runs above 600.
Water follows the same logic for a different reason. A 1,500-gallon plastic cistern carries 400 to 750 kilograms of CO2e before its pump and filter, and in Seattle, where winter rain and summer demand are out of phase, it delivers perhaps 15 to 30 cubic meters a year. City water here takes almost no energy to deliver.
What the same hardware displaces, place by place
Lifecycle emissions per unit delivered, on a log scale: each gridline is ten times the last. Where the on-site bar sits to the right, the on-site system emits more than the service it replaces.
Rooftop solar against the grid grams of CO2e per kilowatt-hour
Harvested rainwater against city supply kilograms of CO2e per cubic meter
Order-of-magnitude ranges from harmonized literature, not from Studio Viridian’s buildings. Source: The Right Scale, § 05.
So the memo’s rule for Seattle is to capture rain for detention and resilience, not for supply. In Adelaide, where water comes from desalination on a coal grid, the same tank is a climate measure.
Carbon is one limit of nine
Kate Raworth’s Doughnut sets an ecological ceiling of nine planetary limits, and the 2025 Planetary Health Check finds seven of them crossed. Carbon isn’t the one the world is furthest past: nitrogen and phosphorus loading and chemical pollution are exceeded by wider margins. Judged across all nine, several of the memo’s conclusions change.
The full ceiling: where each measure helps or hurts, limit by limit
Judgments for a Seattle infill lot, not measurements. Dots above each limit show where the world stands.
World status from the 2025 Planetary Health Check: high risk, increasing risk, within the limit. Ocean acidification moves with the CO2 already counted under climate, so it isn’t scored separately. Source: The Right Scale, § 05.
The biggest shift is stormwater. A chemical from tire wear, 6PPD-quinone, washes off every road and kills coho salmon at concentrations below one part per billion. A rain garden with engineered soil removes it. On a Seattle lot, a rain garden is first a salmon device.
Specifications also matter more than sizing. A heat pump’s refrigerant can erase years of savings if it leaks: a 2 to 4 kilogram charge of R-410A released is 4 to 8 tons of CO2e. Lithium iron phosphate batteries remove cobalt and nickel entirely. Dense-pack cellulose avoids the blowing agents and flame retardants in foam. The backup-only battery comes out worst on every count, at about 60 to 110 kilograms of CO2e per kilowatt-hour of capacity that may never be used, plus water drawn from the Atacama and cobalt mined in Congo.
Who keeps it running
Household resource systems rarely fail because the technology is bad. They fail because the technology needs attention and no one is paid to give it: the cistern’s ultraviolet lamp in a crawlspace, the filter nobody changed, then abandonment.
Where the fleet position sits
Two questions decide whether a resource system keeps working: where the equipment sits, and who runs it day to day
The fleet position is the one combination the market has left empty. Source: The Right Scale, § 03.
Studio Viridian develops, designs, builds and operates a held portfolio in one city, so one route technician can service a dozen buildings, turning household-scale equipment into fleet-scale reliability. Federal policy now points the same way. The 30 percent homeowner credit for solar and storage ended with 2025, while the business credit survives for most projects placed in service by the end of 2027.
Operating isn’t controlling
Running a tenant’s power and water isn’t the same as controlling it. A household that buys from Seattle City Light and Seattle Public Utilities has public rate hearings, discount programs, shutoff rules and an appeal. Bring those services in house and the tenant loses all of them unless the landlord puts them back. So the memo includes utilities in rent instead of reselling them, writes residents’ resilience rights into the lease, attaches stormwater obligations to the land and enrolls batteries in a utility program.
One array and battery, three parties, three written rights
Each party holds the right that matches the consequence it bears, written into a document that survives a change of owner
Whether Seattle City Light will offer a dispatch program to a small multifamily battery, and on what terms, is an open question. Source: The Right Scale, § 04.
Scale is chosen stage by stage
The question the memo started from, household or city, can’t be answered as posed. Processing waste alone runs from sorting and storage through transport, conversion and disposal, and each stage has its own best scale. The memo runs nine tests on every stage, from how far a resource wants to travel to who has to pay attention to it, and defaults to the building.
A library works because demand is intermittent and doesn’t coincide: a thousand households don’t want the same book on the same evening. Hot water, laundry and canning equipment pass that test. Waste fails it, because everyone produces some every day.
Every stage of the four services, placed on the scale ladder
Filled dots are the scale the memo assigns; a bar spans a range. Open circles are exceptions or advocacy positions.
The building or parcel (S2) is the default because most stages land there: it is above the minimum workable size for most processes, it can be serviced on a route, and sharing inside it crosses no property line. Source: The Right Scale, § 06.
Organics are sorted in the dwelling, buffered in the building and converted by the city. Drinking-water treatment and sewage stay with the city. Nothing lands at the district scale except sewer heat recovery, which needs an institution the firm doesn’t have.
Where autonomy is worth buying
Self-sufficiency is worth paying for in proportion to how quickly a household is in trouble when the central system stops.
The failure clock
Time from a central failure to real harm for a household, on a log scale, and how much autonomy is worth buying
The heat-and-smoke row is inferred from the 2021 heat dome, not from a public-health source. Source: The Right Scale, § 06.
Water and power come first, with cooling and clean air close behind; the 2021 heat dome killed hundreds of people in the Northwest. The cheap answers are capabilities, not second systems: a heat pump that also cools, and one sealed clean-air room in every building. Waste comes last. If collection stops for a week, nothing much happens.
One tank, two jobs
Seattle’s RainWise program pays up to roughly the full cost of a cistern in combined-sewer basins, but it requires a small orifice that drains the tank between storms from September to mid-April, because the city is buying detention. Resilience wants a full tank. The memo’s answer stacks the two volumes in one tank.
The dual-mode cistern
A diagram of the principle, not a construction detail
The real detail should be developed with a RainWise-trained contractor so the rebate isn’t forfeited on a technicality. Source: The Right Scale, § 08.
The garden was graded on the wrong test
A four-unit lot can’t feed its residents: perhaps 5 to 15 percent of their produce and 1 to 3 percent of their calories, by the memo’s order-of-magnitude estimate. But a productive landscape returns ten things, and eight of them need no resident to lift a trowel.
What a productive landscape returns
The memo’s yield register: ten benefits, and who has to do the work for each
Source: The Right Scale, § 10.
So the memo makes permaculture the site method on every property, puts a route gardener on contract and treats gardening as an opt-in amenity. Surplus harvest is donated by default, and no resident is promised “passive income.”
The doctrine it leads with is short: decentralize to lighten the commons, not to leave it. Its instrument is the Scale Ledger, the measured maintenance hours that nobody else publishes. Better AI can model a building’s performance; it can’t measure who changed the filter.