Collaborative spaces new trends

The office hasn't disappeared with remote working. Its role has changed. Today, people come in mainly to collaborate, learn and meet one another. At STARC and Optibim, we support companies, public authorities and investors who are redesigning their premises. Here is what we observe on the ground and what it means, both architecturally and technically.

A changing office landscape

Brussels offers a good measure of this shift. According to the Office Observatory run by perspective.brussels, the vacancy rate stood at 7.7% across the Region in 2020, compared with 7.5% in 2019. This average figure hides major differences: 61% of vacant space is located in buildings over 15 years old, and vacancy was higher in certain decentralised districts of the second ring.

A more recent study by perspective.brussels, carried out with the Task Force Bureaux, identified just over one million m² of vacant office space in Brussels in March 2022. In short, well-located and well-equipped premises find tenants. The rest need to reinvent themselves.

In Wallonia, the trend has taken a different shape: that of third places. Coworking | Digital Wallonia is the network of Walloon coworking spaces developed since 2011 by the Walloon Government and coordinated by the Agence du Numérique. These spaces rest on three pillars, Work, Learn and Connect. Here we find the central idea behind the new offices: a good desk is no longer enough, there also needs to be a place where community and exchange can grow.

The new types of spaces

The uniform open-plan floor is losing ground. It is giving way to spaces designed around activity, with zones tailored to each use. Here are the types we most often build into our briefs:

• shared desks (flex desks), bookable, with individual storage (lockers);
• focus pods, small and well insulated from noise, for solo work or calls;
• project rooms equipped for video conferencing, where part of the team joins remotely;
• informal spaces (kitchen, coffee corner, tiered seating) that encourage spontaneous exchange;
• flexible spaces, partitioned with furniture or movable walls, for training sessions and events.

A figure helps to give a sense of scale. Take a team of 40 people, present on average three days out of five. On peak days, attendance often exceeds the average. To avoid frustration, the space needs to be sized for these peak days, not the average. One might, for instance, plan for 28 to 30 desks, plus around ten spots in alternative spaces. This ratio needs adjusting for each organisation, as it depends on job roles, team habits and remote working policy. Analysing actual occupancy over a few weeks is worth more than any general rule.

The most common pitfall is removing desks without creating fallback spaces. Noise then becomes the top complaint, and teams drift back to working from home.

Air quality, acoustics and light

A collaborative space experiences variable and sometimes very dense occupancy. This is where the engineering office plays a decisive role.

Air quality is governed by the Code du bien-être au travail (Code on Wellbeing at Work). According to the FPS Employment, Labour and Social Dialogue, employers must take the necessary technical and/or organisational measures to ensure that CO2 concentration in workspaces generally stays below 900 ppm. This corresponds to a minimum ventilation rate of 40 m³ per hour per person present (art. III.1-34, §3, first paragraph of the code). An exemption up to 1200 ppm, or 25 m³/h per person, remains possible for a low-emission environment demonstrated through risk analysis. However, this exemption requires the prior opinion of the committee and the competent prevention adviser.

Translated into concrete figures, this gives:

• a meeting room for 12 people needs around 480 m³/h of fresh air;
• a floor with 30 occupied desks needs around 1,200 m³/h;
• an event space for 60 people rises to 2,400 m³/h, but only for a few hours a week.

With such variable occupancy, constant-flow ventilation either wastes energy or falls short of air supply, depending on the moment. At Optibim, we generally favour demand-controlled ventilation, driven by CO2 and occupancy sensors, while checking its impact on the building's energy performance (EPB).

Acoustics deserve the same rigour: absorbent ceiling panels, partitions rising all the way to the slab for enclosed pods, and attention to sound transmission through service ducts. As for light, the most heavily used desks benefit from being placed near façades. Video conferencing rooms, on the other hand, cope better with well-controlled artificial lighting.

Transforming rather than building

Many collaborative space projects take place in existing buildings: office blocks from the 1970s to 1990s, former schools, farm outbuildings in Hesbaye or Walloon Brabant. Transformation requires a thorough understanding of the existing structure.

Three points need checking first:

• the load-bearing capacity of the floors, especially when creating densely occupied meeting spaces or compact archives;
• the available headroom for running new ventilation ducts;
• planning status: a change of use or a significant alteration may require a permit, under the CoDT (Wallonia's spatial planning code) or the CoBAT (Brussels planning code). It's best to check this from the sketch stage onwards.

The thinking sometimes goes further. In Brussels, the Office Observatory notes that converting offices into housing contributed around 20% of net housing output in the Brussels-Capital Region in 2018 and 2019. For an investor, a mixed-use project can be a serious option, with part shared workspace and part housing.

Our four-step method

For fit-out or transformation projects, we follow a proven approach:

• Survey: BimBot scans the building in 3D and produces a reliable BIM model, avoiding unpleasant surprises over existing heights, beams and ducts.
• Usage diagnosis: interviews with teams, analysis of attendance rates, inventory of actual activities.
• Integrated design: STARC's architects and interior architects work with Optibim's engineers (structural, HVAC, electrical, EPB) on a single shared model.
• Phasing: Chronoplan organises the works, often in a building still in use, zone by zone and by weekend where necessary.

We apply these same principles in our own offices in Gembloux, where our architects, engineers and BIM team work together every day.

Let's talk about your project

Are you considering redesigning your offices, converting a building into shared workspace, or repurposing an ageing office block? The teams at STARC and Optibim can study feasibility, brief and technical systems with you, starting from the very first survey. Get in touch with us in Gembloux for an initial meeting.