Mastone
Mastone: a property platform with WWS calculations, online brochures and separate access for the team and investors.
Updated on
NetherlandsHours to seconds
Calculation time
Online brochures
Professionalism
One portal
Overview
About Mastone
Mastone is a real-estate firm in Cuijk that buys and sells property directly across the Netherlands, without brokers or brokerage commissions. Through its purchasing arm Mastone Capital, it runs a full-service approach that covers acquisition, renovation, management, rental and uitponden (selling off a portfolio unit by unit). The work leans on a fixed network of appraisers, notaries, contractors and property managers. Valuing homes fast and presenting them well to investors is the daily job, and that job used to live in spreadsheets.
The challenge
Mastone scored homes for the new WWS points system in spreadsheets, with more than 100 conditions to track per property. One slip in a formula could push a home into the wrong category, and every valuation took time the team did not have. On top of that, there were no professional brochures to send investors, so opportunities went out by hand over email, one message at a time. And because the portfolio sat across scattered Excel files, nobody had a single view of what Mastone owned and where it stood. They needed one platform: an admin side for the team and a portal for investors, with the full WWS calculation built in.
The analysis
The WWS values homes using points. Whether the associated maximum rent is binding depends in part on the rental sector and tenancy agreement. For Mastone, we brought together more than 100 calculation rules and conditions previously spread across spreadsheets.
We mapped the calculation logic, including floor areas, energy labels, location factors and WOZ property values. Weightings and exceptions needed to sit in the same calculation so the team wouldn't have to maintain them separately in each spreadsheet.
Beyond the calculations we looked at the way of working. Brochures were shared by hand over email, investors had no portal of their own, and overview was missing because everything lived in separate Excel files.
The calculation was one part of the brief. The same property data model also had to support user management, online brochures and the investor portal.
What we built
WWS points-calculation engine
The custom module processes property data using the more than 100 calculation rules and conditions specified for the platform. The WWS points calculation sits in one place, alongside the data behind it.
3 parts
- Encodes the specified WWS calculation rules, including weightings and exceptions.
- Pulls together the inputs that drive the points: surface-area sums, energy labels, location factors and WOZ values.
- Turns a calculation that took hours of careful spreadsheet work into a result in seconds.
Rent and yield automation
The platform links the points score to the associated WWS rent limit and calculates gross initial yield, or BAR: annual gross rent divided by purchase price. The rent limit isn't legally binding for every property; the rental regime and tenancy details still matter.
3 parts
- Calculation of the rent limit associated with the WWS points score.
- Gross initial yield (BAR) worked out from rent against purchase price, so the investment case is clear at a glance.
- The figures update straight from the property data, no separate sheet to maintain.
Online brochure generator and shareable access
Instead of mailing documents by hand, Mastone now generates a professional online brochure per property and shares it through a link. It fits the firm's direct, broker-free way of dealing with investors.
3 parts
- Online brochure generator with a professional look, built from the property's own data.
- Account management with login and shareable links, so a brochure goes straight to the right investor.
- Sharing happens in a few clicks instead of a stream of one-off emails.
Admin and investor portal on a real-estate data model
One platform with two sides: an admin environment where the Mastone team manages the portfolio, and an investor portal where external investors get their own access and overviews. Both run on a database built for complex real-estate data.
3 parts
- Admin environment for portfolio management, replacing the scattered Excel files with one overview.
- Investor portal with its own access and overviews for external investors.
- Database architecture built to hold complex real-estate data and tie the whole platform together.
The blueprint
- 1Property data input
- 2Points calculation
- 3Brochure generation
- 4Portal & sharing
- 5Reporting
Results
Calculation time
Hours to seconds
In this project, the WWS calculation went from hours of spreadsheet work to seconds in the platform.
Professionalism
Online brochures
Shareable links straight to investors.
Overview
One portal
Team and external investors in a single platform instead of scattered Excel.
Tech & tools
“What used to be a full day's work, we now do in a few clicks. The platform has completely transformed how we work.”
Philippe van der Mark, Matthieu Wiggers & Nino Hermans
Mastone
Part of our service: Custom Applications
Why teams build with TopDevs
- Fixed price, agreed up front
- 100% code ownership, no lock-in
- Prototypes in days, live in weeks
- Modern, AI-native & secure tech
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