How to Convert an Office Building into Rental Housing

Óscar Raynaud· Head of Living, UrbanPay9 Oct 20265 min

Europe has too many obsolete offices and too few homes, and more investors are trying to fix both problems with one building. MSCI data shows that 17% of all central business district office sales in the first half of 2026 were bought for conversion or redevelopment. That is the highest share in fourteen years, against a long-term average of 13%. Residential and hotel use account for more than 70% of the known conversions since 2022.

Converting an office to residential is not simple, and many projects stall. This guide covers how to tell a good candidate from a trap, and why the operating plan matters as much as the architecture.

Understand why the numbers can work now

Two trends meet in a conversion. Older offices are losing tenants and value, while residential values keep rising because of chronic undersupply. Catella's research highlights that gap and names Madrid, Berlin, Dublin, Warsaw and Rotterdam as cities with particularly strong potential for office-to-residential conversion.

AEW tracked the long-run shift. Across Europe's main office markets, the share of office space sold for conversion rose from 9% in 2008 to 2019 to 12% in 2020 to 2024, and it doubled in Frankfurt to 20%.

The spread between office and residential values creates the opportunity. Construction cost, planning risk and timing decide whether you capture it.

Run the feasibility checklist first

Before you make an offer, test the building against six questions:

Floor plate depth: can every habitable room get natural light? Deep plates struggle to deliver light and ventilation to conventional apartments.
Structure and floor-to-ceiling height: do they leave room for new bathrooms, kitchens and services?
Façade and windows: can windows open, and does the façade meet residential acoustic and thermal standards?
Planning: is change of use permitted, and on what timeline?
Cores and escape routes: do stairs, lifts and fire strategy work for residential occupancy?
Cost and timeline: does the budget, with a contingency, still beat new build at the rents the market will pay?

A building that fails two or more of these is usually a demolition candidate, not a conversion.

Match the living product to the building

Deep floor plates that frustrate family apartments often suit compact units around shared spaces. That is why so many conversions become student housing, coliving or flex living. Studios and cluster rooms line the façade, with kitchens, lounges, laundry and study space in the darker core.

Colonial's Santa Hortensia office building in Madrid is a current example. It is being converted into student and flex living within a joint venture with Vita Group, for delivery in 2028. Colonial estimates an unlevered return of close to 10% over seven years on the project. JLL also notes that change-of-use projects are one of the drivers of flex living's expansion in consolidated urban areas.

Design for the operation, not just the drawings

A converted office becomes a building people live in every day, and operational details decide its margin for decades. Plan these before the drawings are frozen:

Access control that works with digital keys from day one.
Parcel rooms and storage, because residents in compact units receive a lot of deliveries.
Laundry and waste routes that do not cross the lobby.
Back-of-house space for cleaning and maintenance teams.

These cost little on paper and a lot to add later.

Decide who will run it before the capex closes

The operator should be at the table during design, not appointed after completion. They will tell you which unit mix rents, which amenities residents actually use, and how many staff the layout needs. The operating agreement also shapes the finance. How to choose an operating model with investors compares the options, and how to launch a build-to-rent scheme covers lease-up.

Where UrbanPay fits

A conversion that opens with hundreds of new residents needs onboarding that scales from the first week. UrbanPay brings remote identity verification, eIDAS-compliant contract signing and account-to-account rent collection together in one flow, reconciled to each unit and each legal entity. The residential solution page shows how it fits a new building.

FAQ

Which offices are best for residential conversion?

Buildings with moderate floor plate depth, good daylight, workable cores and a location with strong rental demand. Deep plates often suit student housing or coliving better than apartments.

Is converting an office cheaper than building new?

It can be, because structure and envelope are reused, but hidden costs in façades, services and fire strategy are common. Budget a meaningful contingency and test it against new build.

Why do so many office conversions become coliving or student housing?

Compact units with shared amenities make better use of deep floor plates, and demand for these products is strong in the same city centres where offices are emptying.

Talk to Óscar

If you run or are planning a coliving, flex living, student housing or build-to-rent operation and want to see how collection, verification and contract signing fit together on your volumes, book 20 minutes with me or write directly.

Book 20 minutes with Óscar · [email protected] · Contact UrbanPay