Methodology and sources
How PlaceProof combines source data, calculations and assumptions for LiveHere, BuyHere and RentHere.
Four different dates
The source date describes the period or state reported by the publisher. Retrieval records when PlaceProof requested data or captured a snapshot. The rule version identifies the implemented calculation basis. Editorial review is a separate, completed action; a new retrieval or build does not automatically renew it.
The public explanations were checked against the current code on 28 September 2026. This is not a new review of every legal rule or external dataset. Existing rule versions and dated source audits remain the subject-matter basis.
Sources by tool
LiveHere uses OpenStreetMap/Overpass, OSRM and regional geocoding and cadastral services. BuyHere uses existing regional rule configurations and pure finance functions. RentHere uses official Observatoire de l’Habitat, Statbel, INSEE, ANIL and Destatis sources, plus regional official references. Tools link to relevant sources; their publishers and licence conditions remain authoritative.
LiveHere
POI distances use the Haversine formula between coordinates, rounded to metres. They are straight-line distances, not routed walking paths. OSRM commute times model driving to selected hubs, without a reliable live-traffic forecast. Street attributes come from OSM tags; parcel polygons are informational.
OSM/Overpass supplies neighbourhood data, regional geocoders find addresses, OSRM models journeys and official regional services provide parcels. Map tiles and optional images have separate providers. Not every facility is mapped; outages, limited coverage and outdated tags are possible. Missing data do not mean something is absent on the ground. A parcel is not a legally binding boundary survey.
View an exampleBuyHere
The price covers only the property. Project cost adds modelled acquisition costs and renovation. Capital funds part of this; the remaining need determines the loan. The monthly payment includes interest and principal. A longer term can lower payments and increase total interest; a higher rate typically increases the burden.
Registration/transfer costs, notary, mortgage deeds and applicable VAT follow the selected existing regional pack. Estimates remain estimates; relief eligibility needs checking. Ongoing maintenance, individual insurance, personal tax and every bank offer are not fully modelled. Rate assumptions and budget indicators are not a credit approval.
View an exampleRentHere
Monthly housing cost includes the recurring items entered; included heating is not counted twice. Move-in liquidity includes the first month, deposit due and one-off expenses. The deposit is blocked liquidity, not a non-refundable expense. Landlord returns use modelled investment and costs; cash flow includes the full loan payment.
Official asking-rent and index snapshots have their own periods and versions. Some regional rent indices and reference tools remain external or manual sources. Asking rents are not legal limits. Rule notices are not a complete contract review. Landlord figures exclude personal income tax and forecasts of property appreciation.
View an example