Service · Software development

Custom real estate software development.

Custom software for property managers, housing associations, owners' association administrators and investment funds. From portfolio dashboards and maintenance modules to tenant portals and integrations with the Kadaster, BAG and your existing package. We build what Aareon, REMS or Twinq can't do, or replace them entirely where that makes sense.

Portfolio managementTenant portalBAG & Kadaster integrationMaintenance app

Off-the-shelf packages rarely cover your entire portfolio.

Aareon, REMS, Twinq, Empire, Cebus: the well-known property suites do a lot well, but hardly any property manager has their entire process within a single package. Lease administration runs in isolation. Maintenance sits in another system. Heating cost settlements still happen partly in Excel. And a tenant portal that truly feels like your brand is usually missing.

We build custom software that closes the gaps where off-the-shelf packages fall short. Sometimes that's an additional module with an API integration, sometimes a full property suite for organisations that have outgrown their package or operate in a niche the market doesn't serve.

We work with commercial property managers, housing associations, owners' association managers, investment funds, property developers and estate agents who have grown beyond the starter package. The question is always the same: how do we keep control of our portfolio without an army of spreadsheets and manual steps? And how do we let tenants, owners and engineers do digitally what is still done by phone?

We have no preconceived view on which package is good or bad. We look at what runs in your organisation, where it chafes, and build on top of it, or replace it where that is economically and operationally sensible. An addition is often smarter than a rip-and-replace; sometimes a new suite is the only way forward.

Three flavours of property software.

Which form suits your organisation depends on what is already in place, how large your portfolio is and which workflows are causing pain. We will advise during our introductory call which route makes sense.

Compact project · fixed sprint budget

Additional module on your existing package

You already run Aareon, REMS or a similar package, but there's one process that falls outside it. A maintenance app for engineers with photo reports. A tenancy-change tool with key management. A dashboard that shows rental yield and vacancy in real time. We build the module and connect it to your core system via API.

API integrationSSOMobilePhoto reporting
Mid-sized project · fixed sprint budget

Tenant portal or partner portal

A secure environment where tenants, owners or owners' association members can handle matters themselves: view invoices, report complaints with photos, retrieve contracts, submit changes, and review service-charge statements. Fully in your house style, with DigiD or eHerkenning where appropriate, and connected to your back office.

DigiD / eHerkenningComplaint flowInvoices & contractsChange requests
Larger project · fixed sprint budget

Fully custom property suite

For organisations that have outgrown their standard package or operate in a niche with no suitable off-the-shelf offering. Portfolio management, contracts, tenants, move-ins and move-outs, maintenance and financial settlements, all in one coherent system that grows with you. Often with deep integrations with the Kadaster, BAG, WOZ data and accounting software.

If you only reconstruct the condition of your property at the end of the year, you are working with estimates. For that, see the app for property observations.

Portfolio dashboardContract managementChanges & maintenanceAccounting integration

What you get at the end.

A working system that connects to your existing infrastructure, plus everything you need to manage and further develop it yourself.

  • The application itselfProduction and staging, running in your cloud (Azure, GCP, AWS) or with us. Includes a monitoring dashboard.
  • Complete codebase and documentationSource code, architecture overview, build instructions and a data model covering all objects, contracts and relationships.
  • Integrations with BAG, Kadaster and your packageWorking integrations with the external data sources you need, plus an API layer to Aareon, REMS, Twinq or your accounting software.
  • Admin and user guideSeparate documentation for your administrators, property managers, technicians and tenants, plus short video tutorials for onboarding.
  • Migration of existing dataObjects, contracts and tenant records, whether from Excel or your current package, cleanly transferred to the new system.
  • Maintenance contract (optional)Monitoring, backups, security patches and ongoing development for a fixed monthly fee. Four response-time levels.

When custom is the right choice.

Four signs that tell us a property organisation would benefit from its own solution rather than yet another off-the-shelf package.

Package limitations

You're stuck in your suite

Aareon, REMS or Twinq does 80% of what you need, but the last 20% is exactly where your competitive edge lies. Workarounds in Excel or standalone tools make the work slow and error-prone.

Specific niche

Your segment is too narrow

Student housing, short stays, holiday parks, care property, a specific type of commercial space: your segment has its own rules and its own processes, which generic packages do not cater for.

Portfolio growth

You're outgrowing your system

What worked with a few dozen properties in Excel does not scale to hundreds. Transfers, maintenance and rent collection call for automation and clear dashboards.

Tenant experience

Your customer experience needs to improve

Tenants expect an app or portal where they can handle things themselves. A phone call for every complaint or invoice query is no longer acceptable, and your team could spend that time better.

Applications we often build.

A selection of the modules and workflows we have delivered for property organisations, or that we most often hear about during introductory conversations.

Portfolio and returns

Portfolio management dashboard

A real-time overview of properties, contracts, tenants, vacancies, rental income and returns per property or cluster. Filter by location, segment or manager. Drill down to an individual property with move history, maintenance orders, outstanding items and market value. For investment funds, a stronger focus on IRR and loan-to-value ratios; for managers, more on operational KPIs.

Vacancy trackingRental incomeReturns per propertyMarket rent comparison
Maintenance & inspection

Maintenance and technician app

Scheduling, work orders, photo reporting and cost tracking for minor and major maintenance. Technicians work in a mobile app with an offline mode for locations with poor reception. Inspections with checklists, photo evidence and automatic report generation. Built for housing associations with their own maintenance service, but equally useful for managers working with external contractors.

Offline on mobilePhoto reportingWork order flowInspection checklists
Tenant experience

Tenant and owner portal

A secure, branded environment where tenants, owners or association members can manage their own affairs. Report complaints with photos, view invoices and payment status, retrieve rental contracts and attachments, submit change-of-tenancy requests, review service charge statements and, in an owners' association context, look back through meeting documents and decisions. Log in via DigiD for social housing, via eHerkenning for business users, or via magic link for lighter use cases.

Complaint flowInvoices & paymentsContract archiveDigiD / eHerkenning
Change-of-tenancy administration

Change-of-tenancy and key management

Handover, inspection, change-of-tenancy maintenance and key handover in one digital flow. Inspection reports with before-and-after photos, cost allocation to the outgoing or incoming tenant, automatic generation of final statements, and a link to your accounting software. For managers with high tenant turnover, this saves days of administration every month.

Check-in reportKey handoverFinal statementPhoto evidence
Financial settlements

Service and heating cost statements

Automatic calculation of service charges, heating costs and shared expenses based on consumption, allocation keys and owners' association decisions. Includes an explanation of each item for the tenant, a draft version for review, a final version with PDF and optional payment. For organisations currently running an annual manual Excel process, this is often the first module that delivers a return.

Consumption importAllocation keysDraft & finalPDF export
Not yet sure about a large project?

Test your idea first: a working prototype in 1 day

With OneDayBuild, we turn your idea into something tangible in one day for €1,150, so you can see whether further development is worth the investment. Decide to go ahead with the full build? Then we credit the full cost.

Explore OneDayBuild →

How a property software project runs.

1

Introduction and process scan

We map out together what currently runs, where the pain points are, and which integrations are essential. For teams with an existing suite, we also look at that suite's API capabilities, as there is often more possible than the vendor lets on.

2

Scope, data model and planning

Workshops with your property team and, where relevant, with maintenance staff or tenants. We outline the properties, contracts, changes of tenancy and financial flows, prioritise what belongs in which sprint, and deliver a concrete scope and plan.

3

Build in two-week sprints

A working build at the end of every sprint. Your key users test along the way, and for portals for tenants or maintenance staff we bring in a small group of users early to gather feedback. Adjustments can be made right up to the final sprint.

4

Migration, rollout and maintenance

Data migration from Excel or your old package, phased rollout across your portfolio, training for managers and users, and ongoing maintenance for security and further development, for as long as you wish.

Property software that connects to your infrastructure.

We don't build in a silo. Our solutions connect with the packages and datasets that are standard in property management, so data doesn't need to be maintained twice.

Property suites

Aareon, REMS, Twinq

API integrations with the well-known management suites, so that our module complements them rather than competes with them. Property and contract data remains authoritative in your core system.

Government data

BAG, Kadaster, WOZ

Addresses and property details from the Key Register of Addresses and Buildings (BAG), ownership information from the Land Registry (Kadaster), and WOZ valuations from municipal datasets. Automatically enriched, automatically kept up to date.

Accounting & identity

Exact, AFAS, DigiD

Rental invoices sent to your accounts, with payment status returned to the portal. For housing associations and social rental, authentication via DigiD; for business parties, via eHerkenning or SSO.

Frequently asked questions.

What property management clients often want to know before we start.

Can you integrate with Aareon, REMS, Twinq or our existing package?
Yes. We have experience with the common property management suites, and we typically build our module as an add-on with API integration, so that property and contract data remains authoritative in your core system. Does your package only offer a limited API or an outdated SOAP interface? Then we'll work out with you and the vendor what is feasible, and where necessary build an intermediate layer, periodic synchronisation, or file import. In some cases we also arrange direct database access through your vendor, provided the contract allows it.
Do you only build add-ons, or also standalone property software?
Both. For organisations that have outgrown their standard package or operate in a niche with no suitable off-the-shelf offering, we build complete custom property suites. For managers who are happy with their core system but are missing specific modules, we deliver standalone add-ons that integrate seamlessly via API integrations. We don't make the choice between extending and replacing in the first conversation; that requires more information about your current workflows, contracts and data.
How do you work with BAG, Kadaster and WOZ data?
We integrate with the official endpoints: BAG for addresses and buildings, Kadaster for ownership information and mortgage status, and WOZ valuations via the national facility. Data is automatically enriched as soon as a new property is created and refreshed periodically, so your portfolio overview is always current. For market rent data, valuation sources and property marketplaces (Funda, Pararius and business equivalents), we integrate depending on the providers and your subscriptions to those sources.
How do you handle GDPR and privacy for tenant data?
Tenant data falls under the GDPR, and in social housing also under stricter frameworks. We work with a data processing agreement, carry out a DPIA for every larger project, and apply encryption both in transit and at rest. Access is always role-based with an audit log, BSN validation where relevant, and data minimisation as a design principle. For housing associations and parties with BAG or BSN integrations, we have standard procedures for retention periods, the right to be forgotten and disclosure to supervisory authorities.
What determines the cost of a property software project?
The number of workflows the system must support, the depth of integrations with your existing package, whether a tenant portal or maintenance app is included, and how much data needs to be migrated. The level of compliance (social housing, BSN, DigiD) also drives the scope. In the introductory conversation we outline the project in scope blocks; afterwards we provide a substantiated estimate based on what will actually be built, not on a templated pricing model.
Do you also work for housing associations, or only commercial property?
Both. Housing associations have heavier compliance requirements (social housing, BSN, DigiD authentication, longer retention periods, Aw reporting), which we take into account as a matter of course. For commercial managers, VvE managers, investment funds and property developers the workflows differ, but the approach is the same: map the process first, then build. Estate agents with their own rental portfolio who have outgrown starter packages also regularly come to us.
How quickly can we go live?
A first working module, such as a maintenance app or a dashboard, can be operational within a few sprints for a small group of users. A complete property suite with multiple integrations and migration is a project spanning several sprints, rolled out in phases so you realise value along the way. We prefer to build something simple that goes live quickly and then grows, rather than a big-bang launch after months of silence.
What if our current package has no API?
Here we look at alternative routes: file export and import on a fixed schedule, RPA-style intermediate steps, or, in some cases, direct database access if your supplier supports it. As a last resort, it is wise to examine the export options of your package thoroughly before moving on to building, as more is sometimes possible than the standard documentation suggests.

Talk to us about your property management software.

A free, half-hour introductory conversation. We listen to your portfolio, your current package and the processes that cause friction, and give direction where it is useful to you. Whether you are looking at a letting software solution, a field service app for engineers or a full enterprise project.

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