Room additions & extensions in Belleville
Belleville is 19e + 20e arr.'s pre-haussmann village + late-19th c. faubourg + 20th c. social submarket. Belleville was annexed to Paris in 1860 along with Montmartre — its hilltop village preserved pre-1860 lot lines and shared courts that survive in current cadastre, so any extension scope first surfaces 1850s-vintage servitudes that may not appear on standard PLU maps.
What a room additions & extensions project looks like here
Belleville was annexed to Paris in 1860 along with Montmartre — its hilltop village preserved pre-1860 lot lines and shared courts that survive in current cadastre, so any extension scope first surfaces 1850s-vintage servitudes that may not appear on standard PLU maps.
The Belleville carrière (gypse) extends from the Buttes-Chaumont down through the arrondissement — IGC reports here are particularly likely to find unmapped voids requiring micropieux foundation systems.
Paris extensions are rare in the historic core — typically attic / combles conversion or rooftop addition (surélévation). PLU governs maximum hauteur plafond, Permis de Construire required, ABF veto on PSMV-listed faubourgs. In Belleville specifically, pre-haussmann village + late-19th c. faubourg + 20th c. social stock means room additions & extensions scope is shaped by the neighborhood's dominant construction typology. Baily's Paris scoping flow factors pre-1860 belleville village fabric and carrière souterraine into the estimate before a contractor is involved.
Start your Belleville scope — Baily asks the right questions.
Pre-seeded for room additions & extensions in Belleville. Mention your 30-110 m² + village houses, your timeline, and any known constraints — Baily factors the mairie 19e/20e + du review queue into the scope.
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Who is Baily?
Baily is named after Francis Baily — an English stockbroker who retired at 51, became an astronomer, and in 1836 described something on the edge of a solar eclipse that nobody had properly articulated before: a string of bright beads of sunlight breaking through the valleys along the moon’s rim.
He wasn’t the first to see them. Edmond Halley saw them in 1715 and barely noticed. Baily’s contribution was clarity — describing exactly what was happening, in plain language, so vividly that the whole field of astronomy paid attention. The phenomenon is still called Baily’s beads.
That’s what we wanted our AI to do. Every inbound call and text has signal in it — a homeowner’s real question, a timeline, a budget, a hesitation that means “yes but.” Baily listens to every one, 24/7, and finds the beads of light.
Baily was a businessman before he was a scientist. That’s our vibe too.
Questions LA homeowners actually ask
Belleville room additions & extensions projects typically run $75K–$385K. Belleville's pre-haussmann village + late-19th c. faubourg + 20th c. social stock, combined with pre-1860 belleville village fabric — pre-haussmann lot lines, puts most mid-complexity projects in the $230K range. Baily scopes the exact band once you describe the work.
Nearest neighborhoods
Same service, adjacent Paris submarkets.