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Old Buildings, Stranded Assets & The Workplace Revolution

Rooftop extensions on older buildings are a smart architectural solution, balancing preservation with modernity. They unlock valuable space in dense urban areas, enhance property value, and revitalize aging structures. However, integrating contemporary additions atop heritage buildings requires a sensitive and strategic approach. Beyond expanding usable space without increasing a building’s footprint, rooftop extensions boost energy efficiency and introduce modern amenities, making older buildings more sustainable. In hospitality, they can create unforgettable guest experiences, from panoramic sky bars to luxury penthouse suites.

An innovative glulam and glass rooftop extension, the first of its kind in Belfast, adding high-quality modern workspace while achieving a striking architectural contrast.

Repurposing older buildings to create flexible, high-performing workplaces while preserving architectural heritage.

Armagh House before repurposing (left)

Stokes House before modernisation (right)

The Challenge of the Outdated Office – A Looming Crisis

The commercial real estate market in the UK and Ireland is at a crossroads. A significant portion of existing office spaces, particularly those built between the 1970s and 1990s – are rapidly becoming obsolete, while historic buildings with architectural and spatial quality remain underutilised. The need for adaptive reuse has never been more urgent.

Recent studies by Cushman and Wakefield reveal that by 2030, 70% of European office buildings could be unsuitable for modern use due to poor layouts, outdated services, and tightening sustainability regulations. In Dublin alone, 64% of current office spaces are at risk of obsolescence. Meanwhile, the UK boasts over 130,000 heritage-listed commercial buildings, many of which remain untapped resources for modern workplaces. These figures highlight a stark choice: adapt or face long-term decline.

Heritage buildings offer what new office buildings often lack: character, identity, and a strong connection to place. At a time when companies are struggling to attract employees back to the office, environments that provide authenticity and inspiration are in demand.

Key advantages of heritage workplaces

Architectural appeal – original facades, timber beams, and brickwork create a rich aesthetic.
High ceilings & daylight –older buildings were often designed with generous proportions.
ESG benefits – adaptive reuse retains embodied carbon, making it more sustainable than demolition.
Increased market appeal –businesses increasingly seek out offices with a strong sense of place.

Completed street elevation, showing the refreshed façade and its relationship with neighbouring buildings.

The Stranded Office Problem – A Growing Threat

While heritage buildings hold inherent value, the bigger crisis is in outdated office stock from the late20th century. These buildings were designed for an era that no longer exists – when deep floor plates, rigid layouts, and fluorescent lighting were the norm. They now struggle to attract tenants, leaving them stranded in the market.

Why these buildings are at risk

Poor internal layouts – large open-plan spaces that don’t support hybrid work needs.
Outdated mechanical & electrical systems – inefficient HVAC, poor insulation, and high energy costs. Instead of demolishing them, these buildings can be repositioned as high-quality workplaces with strategic intervention. Updating building services, reconfiguring layouts, and adding characterful design elements can extend their life and appeal.

The Kelvin on College Square East, Belfast, after refurbishment with buff brick and large-format glazing.

Stokes House on College Square East, Belfast, before refurbishment.

Finished front elevation of The Kelvin on College Square East, Belfast, with adjacent buildings.

What Owners and Developers Need to Consider

The right strategy depends on the type of building and the desired outcome

For heritage buildings – focus on preserving character while upgrading infrastructure.
For stranded assets – modernise building services, reconfigure spaces, and integrate ESG principles.

Pearl Assurance House in Belfast city centre, viewed across a green square with trees, people and pink double-decker buses in the foreground.

Refurbished stair, landing with restored fabric and updated finishes.

Wide view of an open-plan office with desks, task chairs and pendant lighting in a refurbished historic interior.

The Role of Rejen Architects in Adaptive Reuse

At Rejen Architects, we help property owners and developers unlock the potential of their existing buildings. Our expertise spans both heritage conservation and high-performance workplace design, ensuring that each project meets today’s expectations while retaining its unique identity.

Tedford Sail Loft Studios and Coffee House: interior visualisation of the coffee house showing banquette seating, bar stools, timber beams and green and white finishes.

Tedford Sail Loft Studios and Coffee House: existing loft interior with exposed roof trusses, painted brick walls and timber floorboards.

Tedford Sail Loft Studios and Coffee House: interior visualisation showing an open plan studio workspace with exposed roof trusses and a kitchenette.

Top 5 Do’s and Don’ts for Workplace Adaptive Reuse

5 Key Principles for Successful Office Adaptive Reuse

Retain and celebrate original features – Exposed brickwork, industrial beams, or historic facades add authenticity.
Design for flexibility – Workspaces must be adaptable to accommodate hybrid work trends.
Prioritize daylight and spatial quality – Avoid heavy partitioning that blocks natural light.
Incorporate hospitality and residential design elements – Offices should feel warm, comfortable, and inviting.
Integrate sustainability and ESG principles – Reducing embodied carbon is just as important as operational efficiency.

Conclusion: The Future of Work Lies in Adaptive Reuse

The choice is clear: repurpose, reposition, or risk irrelevance. The workplaces of the future won’t be generic glass towers – they will be revitalized heritage buildings and repurposed office assets that have been adapted for modern needs.

The commercial property sector can no longer afford to ignore adaptive reuse. With the right strategy, these buildings can become thriving, future-proof assets that contribute to urban revitalization and sustainability goals.

Finding the Right Solution

While adaptive reuse presents an exciting opportunity, repurposing a building for workplace use is not always the best solution. Each project comes with unique challenges, whether due to planning constraints, structural limitations, or commercial viability. The reality is that there is no silver bullet – each building requires careful consideration to determine its most effective future use.

At Rejen Architects, we specialise in navigating these complexities. Our approach starts with early-stagefeasibility assessments – helping clients understand their options, weigh-up risks vs.rewards, andultimately define the optimal strategy for their building. Whether that means a high-spec workplace,mixed-use development, or a repositioning for a new sector, we provide expert insight to align projectoutcomes with financial, ESG, and user experience goals.

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