Two things: the tier system that grades how much weight a claim can carry, and a starting directory of where to look for each domain.
Evidence tiers
Every claim in the knowledge base carries a tier. The rule that makes this worth doing:
A claim may never be presented more confidently than its tier allows. Tier E is a hypothesis. Tier A is a result. Both are welcome; conflating them is not.
| Tier | Kind of source | Weight | Typical use |
|---|---|---|---|
| A | Measured by us — our own instrumented sites, meter readings, bills, site surveys, verified project outcomes | Highest. Local, current, conditions known. | The basis of anything we claim publicly about results |
| B | Official & peer-reviewed — government and agency data, statistics institutes, peer-reviewed literature, well-documented public datasets | High, but check geography and date | Baselines, benchmarks, physical relationships |
| C | Standards, codes & engineering references — building codes, technical norms, engineering handbooks, calculation methods | High for methods; they state requirements, not local reality | How to calculate; what is legally required |
| D | Industry & vendor — manufacturer datasheets, installer literature, trade associations, price lists | Reliable for specifications and prices; unreliable for performance claims | Product availability, cost, lead time, technical limits |
| E | Practitioner & community — local owners, trades, forums, social media, personal anecdote | Low as evidence, high as signal | Finding out what problems exist and what to investigate |
Working rules
- Tier D performance figures are measured under standard conditions that a Mallorcan finca does not have. Treat them as an upper bound.
- Tier E is how we discover what matters. It is never how we conclude.
- A single source of any tier is a fragile claim. Two independent sources that agree is the minimum for “what we know”.
- When tiers conflict, the lower tier often knows something the higher tier ignored — investigate the disagreement rather than defaulting to the higher tier.
- Every claim records: tier, source reference, and date of the underlying data.
Recording sources
One source note per substantive source, in sources/,
named <year>-<short-slug>.md. Log the source when found, even before reading it.
Minimum fields: title, author/organisation, tier, date of publication, date of the underlying data (often much older), geography covered, how we found it, and which domains it touches.
Where to look — a starting directory
These are candidate starting points, not verified references. Part of the first research sprints is to check each one, find out what it actually publishes, at what granularity, and log it properly. Names and remits of public bodies change; verify before citing.
Climate, weather and water resources (C1, C2, W)
- The Spanish national meteorological agency (AEMET) — station data, climate normals, drought indices.
- Balearic regional government bodies responsible for water resources and for the environment — aquifer status, abstraction regulation, drought planning, water quality.
- The Balearic statistics institute and the Spanish national statistics institute — consumption, housing stock, demographics.
- EU-level climate and environment services (Copernicus and equivalents) — reanalysis data, projections.
- River basin / hydrological plans for the Balearics — usually the single richest document on local water.
Energy (C3, E)
- The Spanish energy efficiency agency (IDAE) — technical guides, consumption benchmarks, efficiency methodologies.
- The EU Joint Research Centre’s photovoltaic assessment tool (PVGIS) — irradiance and yield estimation by coordinate.
- The Spanish grid operator and the Balearic distribution utility — grid data, outage statistics, connection procedures.
- The national energy regulator and the ministry responsible for energy transition — tariff structures, self-consumption regulation.
Building, codes and standards (C5, H, M)
- The Spanish building code (Código Técnico de la Edificación), particularly the documents covering energy performance, water supply and health.
- Spanish and European technical norms (UNE / EN) relevant to water, thermal performance and pools.
- Passive design and retrofit references — Passivhaus and equivalent bodies, and specifically their Mediterranean and retrofit guidance.
- Literature on traditional Mediterranean construction, lime-based building and retrofit of historic stone buildings.
Permitting, land and grants (C5)
- The island council (Consell de Mallorca) — rural land classification, licences.
- Individual municipal planning rules — these vary enormously between municipalities and are the binding constraint in practice.
- Grant and subsidy programmes at national, regional and EU level — high churn; needs a scheduled six-monthly refresh.
Land, soil and planting (L)
- Regional agricultural research and extension services.
- Botanical gardens and native plant societies for species selection and water needs.
- Agronomic references on evapotranspiration and crop/plant water requirements — the FAO methodology is the standard reference.
- Local permaculture, regenerative agriculture and dryland farming networks (Tier E, but rich in hypotheses).
Pools specifically (A1)
- Pool industry associations and technical standards for water treatment and circulation.
- Academic literature on pool evaporation rates and cover performance.
- Natural/biological pool builders and their published design methodologies.
- Regional regulation covering private pool construction and water use.
Market, cost and supply chain (C6)
There is no published source for most of this. It is built by fieldwork: quotes collected, installers interviewed, prices recorded over time. Treat our own accumulating cost records as a Tier A asset — it is one of the few things a competitor genuinely cannot copy.
Adjacent geographies
Regions with comparable climate and constraints, whose experience transfers with adjustment: the other Balearic islands, Cyprus, Malta, Sicily and southern Italy, mainland Mediterranean Spain, Greece, coastal Portugal, and — for drought and off-grid practice — parts of Australia, California and Israel.
Registry index
Once populated, an index of registered sources lives here or in sources/README.md,
grouped by domain, with tier and date. Empty for now.