Sloping-site & sub-sol in 12e Arrondissement (Bercy / Nation)
12e Arrondissement (Bercy / Nation) is 12e arr. — Reuilly's late haussmannien + 20th c. social housing + bercy modernist submarket. The 12e has the highest concentration of HBM (1920s-30s social-housing brick blocks) in Paris — these buildings have a uniform structural language that means renovation specs developed for one HBM block frequently transfer to neighbouring ones, but cooperative co-propriété governance can take 12-18 months to vote any parties communes upgrade.
What a sloping-site & sub-sol project looks like here
The 12e has the highest concentration of HBM (1920s-30s social-housing brick blocks) in Paris — these buildings have a uniform structural language that means renovation specs developed for one HBM block frequently transfer to neighbouring ones, but cooperative co-propriété governance can take 12-18 months to vote any parties communes upgrade.
Bois de Vincennes Site Classé (1960) buffer extends ~300 m into the arrondissement — east-edge buildings face landscape-impact review on any window enlargement or roof terrace.
Paris's signature sub-sol development — Montmartre, Belleville, Buttes-Chaumont. Most arrondissements cap excavation at one storey below principal elevation; BRGM old-quarry screening is mandatory in the 5e, 6e, 13e, 14e, 15e. In 12e Arrondissement (Bercy / Nation) specifically, late haussmannien + 20th c. social housing + bercy modernist stock means sloping-site & sub-sol scope is shaped by the neighborhood's dominant construction typology. Baily's Paris scoping flow factors bercy zac modernist envelope and hbm (habitations bon marché) 1920s-30s social-housing cohort restrictions into the estimate before a contractor is involved.
Start your 12e Arrondissement (Bercy / Nation) scope — Baily asks the right questions.
Pre-seeded for sloping-site & sub-sol in 12e Arrondissement (Bercy / Nation). Mention your 45-130 m² appartements, your timeline, and any known constraints — Baily factors the mairie du 12e + mairie de paris (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
12e Arrondissement (Bercy / Nation) sloping-site & sub-sol projects typically run $245K–$1.3M. 12e Arrondissement (Bercy / Nation)'s late haussmannien + 20th c. social housing + bercy modernist stock, combined with bercy zac modernist envelope — height + footprint fixed, puts most mid-complexity projects in the $748K range. Baily scopes the exact band once you describe the work.
Nearest neighborhoods
Same service, adjacent Paris submarkets.