How to Upgrade to a Sustainable Office Fit Out Without Starting Over

The built environment has a sustainability problem, and it’s not just about new builds. Every time a refurbished office is stripped out again to meet shifting market trends, we lose more than just time and money, there’s also a significant environmental cost.

With the right approach, it’s entirely possible to go from Cat A to Cat A+ through a lighter, more sustainable route that saves materials, cuts carbon, and reduces time to market. A sustainable office fit out begins by working with what you already have. Rather than stripping out recently installed systems or flooring, the smarter move is often about layering in what’s missing: power, data, furniture, and personality.

This article explores how to approach the shift from Cat A to Cat A+ without starting over, and how a sustainable office fit out, commercial logic, and speed to market can all go hand in hand.

Why Landlords Are Making the Leap to Cat A+

The post-pandemic leasing market has changed. More tenants are looking for spaces that are ready from day one, and they’re willing to pay for the convenience. For landlords, this presents a challenge. A traditional Cat A space can sit empty for months while tenants weigh up the cost and hassle of a full fit out, leading to wasted embodied emissions, especially in already refurbished buildings. A 2024 AHMM study highlights the carbon impact of repeatedly replacing Cat A materials, reinforcing the need for selective, sustainable upgrades.  

Tenant-Ready™ spaces, also known as Cat A+, lease faster, reduce vacancy risk, and attract better-quality occupiers looking for flexibility. They’re quicker to deliver, often in a matter of weeks when services are left untouched, minimising disruption, shortening construction windows, and cutting emissions. Fewer deliveries, less site time, and better outcomes from every sustainable fit out. Data from CBRE confirms the growing demand for ready-to-use office space. In Q1 2025, UK office take-up totalled 1.3 million sq ft, 4% above the five-year average, with most top deals involving new or early marketed space. These are precisely the types of properties that offer Cat A+ features: fully finished, furnished, and functional, allowing tenants to move in immediately. According to the UK Real Estate Market Outlook 2025 continued growth in take-up is expected, with prime rental growth forecast in all markets. This clearly signals that tenants are prioritising convenience and flexibility, and landlords who provide Cat A+ offices are best positioned to secure high-quality occupiers and reduce vacancy periods.  

Starting Over Isn’t Sustainable

The carbon impact of replacing perfectly good building systems, finishes, and fixtures is hard to justify. Buildings already account for nearly 39% of global CO₂ emissions, and the embodied carbon from new partitions, flooring, kitchens, ceilings, and joinery can significantly outweigh the perceived benefit of a fresh start. That’s why the smartest Cat A+ upgrades begin with a simple question: What can we keep?

Designing spaces to outlast tenants, rather than starting from scratch every lease cycle, breaks the wasteful churn of fit out and strip-out. Adaptable layouts make this possible: shared desking for one tenant can become hot-desking for the next, while soft seating areas may shift from social zones to informal meeting points. When nothing is glued down, nothing needs to be thrown away. It’s a practical shift that reduces waste and makes sustainable office fit out the default, not the exception.

Selective Interventions That Work Harder

A Cat A+ upgrade doesn’t require a blank slate. Instead, it builds on what’s already there, layering in elements that make the space more usable, more appealing, and more lettable, without major disruption.

Here’s what we focus on when designing Cat A+ fit out spaces:

• Furniture and layout: Modular desks, collaborative zones, soft seating, and loose furniture can be added to create a functional workplace without fixing it to the floor plan.
• Kitchens and social space: Plug-in teapoints, demountable kitchenettes and hospitality-style areas can transform a floorplate with minimal mechanical intervention.
• Meeting rooms: Freestanding pods or glazing systems provide private space without needing heavy structural works or permanent alterations.
• Lighting and controls: Upgrading fittings to support flexible use or zoning while retaining existing wiring and service runs.
• Flooring and ceilings: Keep what works and update only if it’s damaged or technically incompatible.

These sustainable office fit out upgrades are fast, clean, and significantly lower in carbon than traditional refits. And when spaces are designed to flex between tenants, they’re more resilient over time.

The Role of Circular Design in Cat A+

Circularity isn’t just about recycling. It’s about designing with longevity, adaptability, and reuse in mind. And for Cat A+ fit outs, it’s critical.

We work closely with our sister company, Platfform, to embed circular thinking in every part of our projects. As a furniture consultancy, they help us specify pieces that can be reconfigured, relocated, or repurposed between tenants. That includes:

• Furniture with certified recycled content or third-party sustainability credentials
• Desking systems that can be resized or reoriented depending on tenant numbers
• Modular meeting booths and acoustic panels with no permanent fixings
• Soft seating that’s easy to reupholster instead of replace

We also audit what’s already on site to avoid overordering and to explore whether assets from other fit outs can be brought into the scheme. This sustainable fit out approach reduces waste, shortens lead times, and helps landlords respond to demand without resorting to landfill.

What Does a Sustainable Cat A+ Strategy Look Like?

In short, it looks like this:

• Keep the bones: ceilings, MEP, raised floors, lighting grids
• Upgrade strategically: teapoints, FF&E, zoning, colour
• Design for reuse: furniture that can move, evolve, and stay in use
• Work with the right partners: consultants who prioritise circularity and help you source with confidence
• Go faster, not deeper: reduce voids, reduce cost, reduce carbon

Upgrade Without Starting Over

Today’s landlords need more than just lettable space; they need space that performs commercially and environmentally. Upgrading a refurbished space to Cat A+ doesn’t mean undoing what’s already been done. It’s one of the most resourceful steps you can take.

With the right team, a smart design approach, and a circular mindset, it’s possible to deliver a Cat A+ sustainable office fit out that meets tenant expectations, protects previous investments, and actively supports ESG targets.