Solar control on the Costa Blanca: The thermal shield of your Passivhaus villa

Enjoying a villa on the Costa Blanca means living with more than 300 days of sunshine a year. In traditional construction, the only way to combat the intense heat of July and August was to reduce the size of the windows or rely on powerful (and expensive) air conditioning systems.

Under the Passivhaus standard, the mindset changes radically: you can have spectacular floor-to-ceiling windows and a cool house at the same time. The secret is not magic; it is physics and bioclimatic design, applied through strict solar control.

Why curtains don't work to stop the heat

The most common mistake in conventional homes is trying to block the sun from the inside. When thermal radiation passes through the glass and hits an indoor curtain or blind, the heat has already entered the house. This phenomenon, known as the "greenhouse effect," irreversibly overheats the rooms.

For a home to be truly efficient, radiation must be stopped before it touches the glass. That is why at Bersife, we integrate solar control directly into the facade's design.

The geometry of the sun on the Costa Blanca

At Bersife, we don't design shadows by intuition; we do it through mathematical calculations. At the latitude of the Costa Blanca (approx. 38° North), the sun has a highly predictable geometric behavior that we use to our advantage:

• Summer sun: It reaches a maximum tilt of about 75° at noon (falling almost vertically).
• Winter sun: Its maximum tilt barely reaches 28° (entering very horizontally).

Based on these universal physical data, we design two types of protective "shields" for your villa:

1. Fixed protections (Porches, pergolas, and recessed windows)

Instead of the classic industrial concrete overhang, at Bersife we choose to integrate solar protection into the very essence of Mediterranean architecture. For south-facing facades, we design deep porches (nayas), spectacular wooden pergolas, and recessed windows (set back into the facade).

These structures are not just aesthetic; they are calculated to the millimeter. Thanks to the 75° angle of the summer sun, the roof of these porches projects a shadow that exactly covers the entire window, blocking the heat. In winter, when the sun is much lower (28°), the geometry of these arches and beams allows the radiation to penetrate deep into the room, heating the interior passively and for free.

2. Dynamic protections (Louvers and Screens)

East and west facades receive the almost horizontal sun of dawn and dusk. Here, fixed porches are not enough. For these areas, we use mobile systems connected to the home automation system:

• Adjustable aluminum louvers: They act as an exterior physical barrier that the user can angle according to the time of day.
• Micro-perforated screens: Exterior technical fabrics that block the thermal impact but maintain transparency so as not to lose the views of the garden or the sea.

Glass technology (The Solar Factor or "g-value")

The final filter of solar control is the glass itself. In Passivhaus villas, we use high-performance glazing where we evaluate the Solar Factor (g-value).This technical data indicates what percentage of heat passes through the glass. While standard glass can let in up to 75% of the heat (g = 0.75), at Bersife we install technical glass capable of drastically reducing that energy input while maintaining intact light transmission.

The final result is a home that breathes luxury, bathed in natural light, yet thermally armored against extreme heat.

‍

Frequently Asked Questions (FAQ)

1. Can I have large windows without the house turning into an oven in summer?

‍Absolutely. The key is to equip those windows with exterior protections (such as strategic porches or louvers) and use glass with a low Solar Factor (g-value) that blocks the heat without darkening the room.

2. Is it better to put the blind inside or outside the window?

‍Always outside. An exterior blind stops the radiation on the facade, while an interior blind allows the energy to pass through the glass, creating a greenhouse effect that irremediably heats the room.

3. Will I lose the views if I use exterior solar protections?

‍No. There are technological solutions such as micro-perforated screen fabrics or adjustable louvers that block direct thermal impact but maintain transparency, allowing you to enjoy the views of your plot.