Project ideas from Hacker News discussions.

The tiny holdout building in the middle of Macy’s is back in view

Original Article

Hacker News Discussion

📝 Discussion Summary (Click to expand)

Top Themes from the Discussion

Theme	Summary	Supporting Quote
1. The building is essentially empty and not legally usable for residences	Commenters note that the structure is mostly vacant, with only the ground‑floor shop occupied, and that it would fail New York’s residential window and habitability requirements.	“Based on the pictures I can’t imagine anyone legally living there.” – nkrisc
2. Billboards and advertising revenue dominate the building’s purpose	The majority of income comes from renting wall space to advertisers; converting the upper floors to apartments would be far less profitable than the current billboard setup.	“Renting any part of that building out is likely not worth the hassle compared to the ad revenue, as you noted.” – nkrisc
3. It’s a hidden urban oddity that many passers‑by never notice	Long‑time locals and visitors are surprised to discover the building hidden behind billboards, highlighting how such structures can stay unnoticed in plain sight.	“I used to work one block from there… had no idea it was hiding something like that.” – mbStavola

🚀 Project Ideas

HiddenHoldout Tracker

Summary

A dashboard that continuously scans city planning databases, aerial imagery, and permit filings to surface hidden holdout buildings (e.g., Times Square holdout) and notifies owners, investors, and journalists.
Detects undocumented structures behind billboards or commercial facades.

Details

Key	Value
Target Audience	Real‑estate analysts, urban planners, institutional investors
Core Feature	Automated identification and alerting of concealed buildings using computer vision and public records
Tech Stack	Python, Django, PostGIS, AWS S3, Google Earth Engine, React
Difficulty	Medium
Monetization	Revenue-ready: subscription tiers ($29/mo basic, $149/mo pro)

Notes

HN commenters often wonder how such buildings stay empty; this tool makes them visible, fulfilling the desire for transparency.
Potential for market intelligence reports and city‑level policy analysis.

BillboardRevenue Optimizer

Summary

SaaS that helps owners of billboard‑dominated properties evaluate the trade‑off between leasing space for ads versus converting parts of the building to residential or commercial use, factoring in zoning, tax, and revenue forecasts.
Interactive profit calculator.

Details

Key	Value
Target Audience	Property owners, real‑estate developers, advertising agencies
Core Feature	Revenue simulation engine comparing billboard lease income vs alternative uses with tax implications
Tech Stack	Node.js, Express, TypeScript, PostgreSQL, D3.js for visualizations
Difficulty	Low
Monetization	Revenue-ready: usage‑based pricing ($0.01 per simulation, capped at $50/mo)

Notes

Several HN users debated the profitability of billboard leases versus residential rent; this tool gives a concrete answer, satisfying that curiosity.
Easy integration with existing ad‑sales pipelines could accelerate adoption.

SpaceHaven Marketplace

Summary

A peer‑to‑peer marketplace that lists underutilized or hidden urban spaces (e.g., rooftop billboard platforms, vacant floors) for short‑term creative uses like pop‑up galleries, AR experiences, or micro‑studios.
Connects space owners with artists, startups, and event organizers.

Details

Key	Value
Target Audience	Property owners with idle space, artists, experimental startups
Core Feature	Listings and matchmaking for hidden or partially occupied spaces, with safety and legal templates
Tech Stack	Ruby on Rails, Firebase, Stripe, React Native
Difficulty	Medium
Monetization	Revenue-ready: 10% transaction fee on each booking

Notes

Commenters expressed fascination with discovering such oddities; the platform makes them discoverable and usable, turning curiosity into utility.
Low friction onboarding could drive rapid community growth.