Nim Dang — a stock exchange for square metres of Tehran
Tehran property sold by the square metre, then resold between holders, with a low/fair/high gauge grading every peer asking price but never the platform’s own.
Company
Independent
Role
Product designer & strategist
Period
2022
Type
Product · Systems
Industry
Real estate · fractional ownership
Team
One designer’s file: a single component library and 191 screens
Tools
Figma
The problem
Make an indivisible asset divisible, then liquid, with no market maker to set the resale price.
The role
Product designer and strategist across a 430-component design system and 191 screens.
The result
A complete design record — primary sale, visit booking, portfolio and a peer exchange — with no launch evidence on file.
Figure 01
Figure 01The primary market on a phone: listings priced per metre, a property with its appraisal and title documents, and the trading hall where holders resell.
01Context
Half a dang
Nim Dang names itself after the unit it is trying to break. A dang is the traditional Persian unit of property title — a property is held in six dangs — and “nim dang” is half of one. The footer says the rest out loud: «نیم دانگ، فروش ملک متری», selling property by the metre.
In Iran, real estate is the default store of value against inflation, and a Tehran flat is priced far beyond an ordinary saver. The product’s answer is fractional ownership with a secondary market attached: buy two square metres of a building you could never buy outright, watch it revalue, sell the metres on.
02Problem
Divisible, then liquid
First, a flat has to become a quantity a person can hold a little of — a price per unit, a minimum ticket, a valuation anyone can check, and enough legal and physical evidence that a stranger will pay for it: an appraisal report, title documents, and a visit booking for people who will not buy a building from photographs.
Then it has to be liquid. Fractional ownership without an exit is an illiquid asset in smaller pieces, so holders need a second market where they sell to each other — which means discovering a price with no market maker, without letting the floor become a place to overcharge the next buyer.
Pick a day on the Shamsi calendar.
Pick a time.
The visit is registered.
Figure 02A physical visit booked inside the purchase flow, for buyers who need to see the building.
03Approach
The file records its own order of work
Figma node IDs increase as nodes are created, so reading each section’s ID range gives the order it was drawn in. The sequence is not the one a tidy case study would claim afterwards: the transaction was designed before the shell. Selling and visiting came first, browsing and valuation second, and log-in, splash, rules and profile — where most products start — came later.
The exchange was attempted early as “stock halls”, abandoned, and rebuilt in the final phase as the trading hall, at roughly ten times the size.
Sections in the order they were drawn
01
OnboardingThe first frames in the file
02
Stock hallsThe exchange, first attempt — 2 screens
Before
Stock halls: one card, terms as a list.
After
04Solution
A gauge on both sides of the trade
On the seller list, every offer states how it is being offered, and there are two kinds: a direct offer from the platform, and a resale by another holder in the trading hall. Peer resales, and only peer resales, carry a three-segment gauge labelled “the seller’s pricing” — low, fair, high — with the offer’s position marked. Direct offers carry none: the platform does not grade itself.
The same gauge appears on the other side of the trade. The pricing step shows a price stepper, suggested prices and the identical bar, relabelled “your pricing”, moving as the seller sets a number. It anchors a seller before they list and warns a buyer at the point of purchase, with a soft signal rather than a hard cap.
01«عرضه نیمدانگ» — the platform’s own offer carries no gauge
02«ایوان معاملات» — a resale by another holder
03«قیمت گذاری فروشنده» — the seller’s price, marked low, fair or high
04Price per metre and price per share read the same, while 30 shares are 24 metres
Figure 04The seller list: only peer resales are graded.
Figure 05The seller’s side: “your pricing” moves as the price is set.
05Key decisions
Market design in three choices
The exchange rests on three decisions the file makes visible.
01
Grade only peer resales, never the platform’s own offers
A platform grading its own price is not a signal; grading other holders’ prices is. Direct offers carry no gauge at all.
Trade-off
The platform’s own pricing has to be trusted on its appraisal alone.
02
A soft signal, not a price cap
A cap would simply be worked around. A gauge anchors a seller before listing and warns a buyer at purchase, without forbidding a price.
Trade-off
An overpriced offer can still be listed, and bought.
03
Design the transaction before the shell
Selling, visiting and valuation are the product; log-in, splash and profile are commodity screens. The build order puts them last.
Trade-off
The shell reached its final form late, after the flows it frames.
06Critique
What is a square metre called?
The product never settles on a name for the thing it sells, and the inconsistency runs through the core flow:
List cards price it per metre, and the detail page gives the same quantity a second label.
The trading hall and the portfolio switch to shares.
The brand is named after a third unit entirely: the dang.
Buy: 25 metres per share — and 25 metres is 2 shares.
07System
A design system at 0.0.1
430 components across colour, typography, form fields, buttons, modals, toasts, headers, tab bars and icons, labelled in the file as version 0.0.1 — one hand, one set of colour and type tokens, and 191 screens drawn against them.
Both themes are real where they exist: the wallet swaps true tokens rather than tinting an overlay, and the property list, the trading hall and the sell sheet all have dark versions. The portfolio list and the add-property flow stayed light only.
Figure 07The colour board: labelled ramps, one accent, version 0.0.1.
Light
08Outcomes
A design record, not a launch
There is no evidence in the file that Nim Dang shipped, and no numbers to report. What it holds is a complete design for both markets.
A primary sale with appraisal, countdown and visit booking
Listings priced per metre, title documents on every property, visits booked on a Shamsi calendar.
Delivered output
A peer exchange with a two-sided fairness gauge
The trading hall, the seller list, and the buy and sell sheets.
Delivered output
A 430-component Persian design system
191 screens drawn against one library, in two themes where it counts.
Delivered output
09What I learned
What I’d change
01
Name the unit before you design the market
Metre, share and dang are three mental models for one asset, and the product uses all three inside a single purchase. Everything downstream — the cards, the gauge, the portfolio — inherits the ambiguity. It was a vocabulary decision, and taking it late made it expensive.
02
The strongest idea deserves the loudest treatment
The low/fair/high gauge on both sides of a peer resale is the most defensible thing in the file, and it appears as one small bar inside a bottom sheet. It should have been what the product led with.
03
Clear the placeholders before they become the product
English placeholder strings still sit where the gauge’s value belongs. Left long enough, a placeholder stops reading as unfinished and starts reading as the design.
