Architecture in the service of wellbeing

People often talk about square metres, budget and deadlines. Yet what occupants remember about a home is a feeling: a bright room, a quiet bedroom, a living room that stays cool in July. In this article, we open the doors of our Gembloux offices to show how STARC and Optibim turn that feeling into design decisions.

Wellbeing is shaped from the very first lines

At our practice, most of the choices that matter for comfort are made very early on. Orientation, room depth, the size and position of window openings, the location of ducts: all of this is set at sketch stage. Correcting these choices after the building permit is expensive. On site, it is often impossible.

That is why, from the very first meeting, STARC's architects work alongside Optibim's engineers. The architect designs the space. The engineer checks in parallel what that space will deliver in winter, in summer, by day and by night. This ongoing dialogue is the basis of our method.

The regulations point in the same direction. According to SPW Énergie, Wallonia's EPB regulations (PEB) aim to guarantee buildings that are healthier, more comfortable and more energy efficient. Comfort is therefore not a bonus: it is part of the objective.

Natural light, our first instinct

A room with plenty of daylight changes everyday life. It also reduces the need for artificial lighting. To assess our proposals, we rely on the European standard EN 17037, which covers four aspects of daylight: the amount of natural light, the quality of the view through windows, exposure to sunlight, and protection against glare.

In practice, at the preliminary design stage, we check:

• the depth of living spaces relative to window height (a very deep room with low windows stays dark at the back);
• the view outside from seated positions, not only when standing;
• actual sunlight exposure, taking neighbouring buildings and vegetation into account;
• the risk of glare in home offices and west facing rooms.

When renovating farmhouses or older homes, light is often the weak point. Walls are thick and window openings narrow. Opening up a bluestone or brick façade then calls for genuine dialogue between the architect, the structural engineer and, often, the planning department.

Air and summer comfort, Optibim's quiet work

A highly insulated, airtight building must be well ventilated. Otherwise, moisture and pollutants build up. SPW Énergie points out that, since 1 January 2021, all newly built buildings must meet the nearly zero energy standard (NZEB, known as QZEN in Wallonia). This level of requirement makes ventilation even more decisive for occupants' health.

At Optibim, this translates into several steps:

• ventilation sized room by room, with grilles placed away from beds and duct routes planned from the outset;
• attention to the noise of ventilation units, which occupants sometimes switch off when it is too loud (the worst-case scenario);
• an airtightness test (blower door) that identifies leaks before finishing works, when they are still easy to fix;
• an overheating risk analysis as part of the EPB (PEB) calculation.

Summer comfort has become a real issue. The Union Wallonne des Architectes reports that the 2026 changes to the EPB (PEB) method will notably broaden the recognition of passive cooling systems. We always favour this order: external solar shading, thermal mass, night ventilation, and only then, if needed, active cooling. To give you an order of magnitude for renovation, one inspection body estimates that a package of solar shading, controls and secured night time openings costs between 6,000 and 17,000 euros depending on the level of equipment. These figures need to be refined for each project.

Calm is designed too

Noise from neighbours is one of the leading sources of conflict in shared ownership. It is best addressed at design stage. In Belgium, the reference standard is NBN S 01-400-1. In July 2022, a revised version of NBN S 01-400-1, covering acoustic criteria for residential buildings, was published. The criteria of this revised standard apply as good practice rules to residential buildings for which the planning permission application was submitted after 1 January 2023.

In our apartment buildings and office to housing conversions, we pay particular attention to:

• the stacking of rooms (avoiding a living room above a neighbour's bedroom);
• floating screeds and the acoustic decoupling of floors;
• the routing of waste water pipes and technical ducts;
• insulation of the street facing façade.

In renovation, the standard's performance levels are not always achievable. Bruxelles Environnement's Sustainable Building Guide then states that the project author must inform the client in writing, before work begins. We do this systematically. It is a matter of honesty towards you.

Starting from the real building, not an approximate plan

Designing an existing space well requires knowing it precisely. Archive plans are often inaccurate by a few tens of centimetres, sometimes more. For a courtyard farmhouse or a Brussels building from the early twentieth century, these discrepancies change everything: ceiling height, the position of a beam, the possibility of opening up a window.

This is the role of BimBot, our surveying service. The 3D scanner, the drone and 360° photography provide a faithful model of the existing building. Our architects can then test light, circulation and layout on a reliable basis. The result: fewer surprises on site and spaces that deliver on their promise.

In Brussels, the planning framework is also evolving. The future regional planning regulation, Good Living, is structured around three chapters: open spaces, urbanity and liveability. Its adoption timetable has been postponed several times. For each project, we therefore check which text applies on the date the permit application is submitted.

What we check before validating a plan

Here, in summary, is the checklist we go through internally before presenting a preliminary design:

• does each living space receive enough natural light and offer a view;
• are the bedrooms protected from street and neighbour noise;
• do south and west facing façades have external solar shading;
• is ventilation integrated into the plans, with realistic duct routes;
• are outdoor spaces (terrace, garden, planted swale) genuinely usable;
• is rainwater management treated as a landscape asset rather than a constraint.

None of these points is spectacular on its own. Together, they make the difference between a compliant home and a home where people feel good.

Do you have a new build, renovation or conversion project in Wallonia or Brussels? Let's talk about it early, while the choices that matter for your comfort are still open. The STARC and Optibim teams welcome you in Gembloux (Sauvenière) to review your project, from initial sketch through to technical studies.

Frédéric Odent, director