300 Demott — Renovation Costs

How to read this. Planning-grade 2026 estimates at Long Island labor for upper-mid to luxury finishes — not bids. Scope is everything visible in the renderings except movable furniture: paint & wall treatments, lighting, mirrors & art allowances, plumbing fixtures & hardware, millwork, window treatments, and all exterior/hardscape work are in; sofas, beds, tables and rugs are out. The house is a 2024 full renovation (~5,015 sf), so unlike an old-bones project the contingency here isn't for knob-and-tube surprises — it's for envelope tie-ins, stone lead times, and the Village's architectural review. Line items are point-planning ranges (low–high); big-ticket systems carry wider bands. Where a public price benchmark anchors a number, it's linked in Sources.

I · The Modern Estate

Limewash · black steel · brass · romantic gardens

II · The French Château

Limestone · slate mansards · bronze · parterres

Soft costs — the stack on top of construction

Timing — phased schedule

Phase	Scope	Modern Estate	French Château
0 · Design & approvals Designer/architect drawings, Village of Rockville Centre building permit, architectural review for facade/roof work (Château).	Drawings, permits, orders placed	6–10 weeks	12–20 weeks
1 · Exterior envelope Château path is the long pole: stone cladding ~8–12 weeks on site after 10–16 week material lead; slate + mansard framing overlaps.	Facade finish, windows, roof (S2), doors	4–8 weeks	16–26 weeks
2 · Interiors Paint/limewash, floors refinished, millwork & library, baths re-fitted, lighting swapped. House is livable-adjacent through most of it; floor refinish needs 1–2 weeks out.	All interior line items	8–12 weeks	12–18 weeks
3 · Landscape & pool yard Hedging, beds/parterre, drive or motor court, pool deck, glass fence, fountain (S2). Weather-window dependent; overlaps Phase 2.	All site work	4–8 weeks	8–14 weeks
Realistic calendar, overlapped		4–6 months	10–14 months

Where each vision lands. Renovated Rockville Centre colonials near South Side trade around $520–640/sf. The Modern Estate adds roughly /sf to your basis on 5,015 sf — with the window-replacement line swapped for the paint-the-frames alternative it stays a defensible inside-the-band play. The Château adds about /sf: limestone, slate and a cobbled motor court price like the hôtel particulier they create — a love-letter build for a forever house, not a resale spreadsheet. Both scenarios assume you already own the 2024 kitchen, baths and systems this house ships with — that's what makes either vision a finishes-and-envelope project instead of a gut.

Sources & benchmarks (proof, not vibes)

Limewash on brick, professional: $1.50–$6.00/sf — HomeGuide, NextGen Painters
Natural stone / limestone veneer, installed: $14–$43/sf (limestone at the top of the band) — HomeGuide, Homewyse, Fixr
Slate roofing: natural $20–$35/sf installed; synthetic $9–$20/sf — Angi, HomeGuide, This Old House
Frameless glass pool fence: ~$150–$210/lf installed — Homewyse, HomeGuide, Angi
Premium replacement windows: $800–$1,400 installed (Marvin Infinity) to $4,000 (custom divided-light/clad) — HomeGuide (Marvin), HomeGuide (Andersen)
Permits: Village of Rockville Centre calculates fees per project from its schedule at application — RVC Building Department, RVC Permits/Fees
Everything unlinked: Long Island planning ranges consistent with the benchmarks above and the ny-house-move dossier norms (upper-mid finishes, GC-managed).