Natural lighting in the house design: health, savings and comfort

Updated on 07/06/2026 by EZA Engenharia

Natural lighting in a house's design is one of those points that directly affect the family's comfort, health and electricity bill, yet many people treat it as if it were just an aesthetic detail. In Criciúma and the surrounding region, where the climate swings between days of strong sun and stretches of overcast skies, deciding the solar orientation and the openings right at the start of the project makes a real difference in the daily life of those who live in the house. After more than 35 years designing and building high-end houses in the region, we at EZA Engenharia have learned that this care is part of the engineering of the project, not a whim of the architectural drawing.

Why solar orientation should be defined before the floor plan

Many people think solar orientation is a fine-tuning matter, something you sort out once the floor plan is ready. On the project it's the opposite: where the house will sit on the lot in relation to the sun should be one of the first decisions, because it determines where the rooms go, the size of the windows and even the shape of the roof.

In Criciúma, the morning sun comes in from the east side and the afternoon sun from the west, and the north receives more constant sunlight throughout the day. A sunlight study done on the actual lot, taking into account the neighboring buildings, the trees and the topography of the plot, avoids a mistake that only shows up after the family is already living there, like a bedroom that gets too hot in the afternoon or a living room that stays dark all day.

This kind of technical analysis is what separates an in-house engineering design from a generic floor plan merely adapted to the lot.

Openings: type, size and position make all the difference

Installing a large window does not guarantee good natural light on its own. The performance of an opening depends on several factors that need to be considered together:

Each project calls for a different combination, according to the orientation of the façade, the surroundings and the lifestyle of those who will live in the house. That is why an off-the-shelf catalog solution rarely works as well as a project designed specifically for that lot in Criciúma, Içara, Forquilhinha, Nova Veneza, Cocal do Sul or Balneário Rincão.

• Position of the opening in relation to the sun's path throughout the day and the seasons
• Type of glass and window frame, which affect heat gain and acoustic comfort
• Shading elements, such as eaves, brise-soleils and canopies, to hold back excess sun
• Cross openings that combine light with natural ventilation

Health and well-being: what natural light does for the body

Getting natural light regularly throughout the day helps regulate sleep, improves mood and reduces that feeling of tiredness that comes from a poorly lit indoor environment. This matters even more in homes where the family spends much of its time in a home office, studying or working remotely.

A space with well-distributed natural light also tends to accumulate less humidity, which helps indoor air quality and reduces the risk of mold in more humid climate regions, such as the coast and the interior of Santa Catarina.

Kitchen, home office, and living area usually do well with direct morning light, while the bedroom calls for more controlled light that can be darkened when it is time to rest.

Energy savings without giving up comfort

A project that makes good use of natural light reduces the reliance on artificial lighting for much of the day, and that is already direct savings on the energy bill. But the benefit doesn't stop there.

When the solar orientation is thought through carefully, the house also spends less on climate control. A facade exposed to the afternoon sun without proper protection increases air-conditioning use, while a well-ventilated space with the right shading keeps the temperature more stable all year round.

This kind of efficiency does not depend on expensive technology. It depends on design decisions made at the right time, and that is why it is worth investing time in planning before starting the project.

The role of in-house engineering in this result

There is a difference that makes all the difference between a construction company and a real-estate developer. The real-estate developer usually develops projects for sale, with standardized designs aimed at a broad audience. The construction company, like EZA, works made-to-measure, from the study of the land and the design to the execution of the project, with an in-house engineering team following every stage.

This structure is what makes it possible to adjust solar orientation, openings and materials specifically for the plot and for each family's way of living, something a generic plan does not deliver. The result shows in projects such as Residence V.S, in Criciúma, and Residence A.F, in Balneário Rincão, where natural light, thermal comfort and premium finishes were treated as part of the same project, not as separate items.

EZA has been building high-end houses in Criciúma and the region for over 35 years, and the care with natural lighting in the house design comes as part of the package along with in-house engineering, the customized architectural design and the premium finish. If you want a house that makes the most of the sun the right way, uses less energy and has every room well lit, talk to our team. Reach out on WhatsApp (48) 99191-2018, send an email to [email protected] or take a look at eza.com.br to see EZA's complete portfolio of projects.