Deloitte's 2025 CRE Outlook found that 54% of commercial real estate teams cite legacy system compatibility as their number one barrier to technology adoption. This figure is striking not because it's surprising but because it points to a structural problem with how real estate technology is typically sold: as a replacement for existing systems rather than a complement to them.
The replacement approach has an obvious commercial logic from the vendor's perspective. A platform that becomes the system of record for everything — property management, accounting, investor reporting — is a larger contract with deeper integration and higher switching costs. But for the institutional fund manager evaluating it, the replacement approach carries risks that are frequently underestimated.
Why replacement projects struggle in the Swiss institutional context
Swiss institutional real estate is characterised by a specific organisational structure that makes replacement projects difficult. Fund managers do not operate buildings directly. They engage régie partners — property managers — who manage buildings on their behalf using their own systems and processes. A fund manager with eight régie partners is dealing with eight independent organisations, each with their own system preferences, their own workflows and their own client relationships that extend well beyond any single fund.
A technology project that requires régie partners to change their systems is not a fund manager technology project. It is an industry transformation project — one that requires convincing multiple independent organisations to incur implementation costs and operational disruption for the benefit of one client relationship. This is rarely achievable and almost never worth attempting.
Enterprise property management platforms (Yardi, MRI, RealPage) are built on the replacement assumption. Their architecture is designed to be the operating system for an entire property management operation — leases, maintenance, tenant management, accounting. The value proposition is comprehensive; the implementation requirement is equally comprehensive, typically running to six to twelve months and requiring significant change management across the entire organisation, including régie partners.
For Swiss fund managers whose régie relationships are arms-length and whose implementation authority extends only to their own organisation, this architecture is fundamentally mismatched to their operational reality.
What the additive architecture looks like
The additive approach is architecturally different. Rather than replacing régie systems, it connects to the data they already produce. The portfolio management platform sits above existing property management systems — ingesting their outputs, standardising and validating the data, and providing the consolidated, regulatory-ready layer that the fund manager needs without requiring the underlying systems to change.
From the régie's perspective, this means continuing to operate their existing systems exactly as before, and delivering data to the fund manager in a structured format — typically via a defined export process or an API connection to their existing platform. The régie's operational workflow does not change. Their data flows into the fund manager's platform through a defined integration, where it is transformed, validated and consolidated.
From the fund manager's perspective, this means a much shorter implementation path, lower implementation risk, and no dependency on régie co-operation for the success of the project. The integration work happens at the fund manager level — building the connectors and mapping rules that translate régie data into the fund's schema — without requiring operational change from the PM partners.
The ecosystem, not the system
The additive approach reflects a different mental model of what portfolio management infrastructure is. Rather than a single system that does everything, it is a layer that sits above an ecosystem of existing systems — aggregating their outputs, resolving their inconsistencies, and providing the structured view that fund managers and regulators require.
This model is consistent with how institutional real estate actually operates. Régies will continue using their property management systems — Quorum, Garaio REM, W&W Immo Informatik — because those systems are optimised for their operational needs. Accountants will continue using their accounting platforms. Valuers will continue using their valuation models. The portfolio management layer connects to all of them, drawing structured data upward rather than pushing operational change downward.
The MRI PropTech Trends 2026 report identified this as the direction of travel for the industry: "organizations will expect solutions to feel unified — multiple solutions will become truly integrated workflows." The additive architecture is the mechanism by which unified reporting is achieved without unified systems.
Implementation reality: additive vs replacement
The implementation difference between the additive and replacement approaches is substantial. A replacement project — moving régie operations to a new property management platform — typically requires six to twelve months, significant change management effort, and a parallel running period during which both old and new systems operate simultaneously. The cost is substantial and the disruption to régie operations is real.
An additive implementation — deploying a portfolio management platform that connects to existing régie systems — typically takes six to eight weeks for a fund of standard complexity. The implementation work involves configuring data connectors for each régie's existing export format, defining validation rules for each PM's data conventions, and setting up the reporting templates required by the fund's investors and regulators. Régie operations continue without interruption.
This implementation speed is not just commercially attractive — it is a governance advantage. A shorter implementation means a shorter period of parallel operation, fewer opportunities for data divergence between old and new processes, and earlier access to the improved data quality and audit trail that the new platform provides.
The right question to ask vendors
When evaluating real estate portfolio management platforms, the most important architecture question is simple: does this platform require my régie partners to change their systems or their workflows in order for the implementation to succeed?
If the answer is yes, the implementation is more complex and more dependent on régie co-operation than you may have been told. If the answer is no — if the platform is designed to connect to existing régie systems rather than replace them — you are evaluating a platform built on the additive model.
The distinction determines not just implementation cost and timeline, but the long-term flexibility of your technology stack. An additive platform can accommodate new régie partners without requiring them to change systems. It can connect to new data sources as they become relevant. It positions the fund manager as the aggregator of an ecosystem rather than the owner of a monolithic system — which is exactly the right architectural position for an organisation whose operational execution is distributed across multiple independent régie partners.
STREETS is additive by design
STREETS connects above your régie partners' existing systems — no replacement, no disruption to property manager workflows. Implementation in six to eight weeks. Your régies keep their systems; you get the structured, validated, regulatory-ready data layer above them.
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