In short: how to orient a house near Barcelona
Near Barcelona, the living room and the main glazing work best facing south and protected by an overhang or pergola: in summer the sun is high and the overhang cuts it off; in winter it is low and comes into the house. West is the hardest orientation and calls for vertical or movable screens. East suits bedrooms and the kitchen; north suits a study, plant rooms or a workshop.
This is a starting point, not a rule. The plot, the slope, the neighbours and a sea view often pull the house another way, and then the answer lies in shading rather than orientation.
Sun geometry: the numbers for our latitude
Barcelona sits at roughly 41° north. At noon on the summer solstice the sun climbs to about 72° above the horizon; at noon on the winter solstice, only 25 to 26°. That difference is what makes a south facade controllable.
A simple example. Above a 2.4 m tall south-facing window, an overhang about 75 cm deep fully shades the glass at summer noon. In winter, the shadow of the same overhang covers only the top 35 to 40 cm, and the sun warms the room. Make it one and a half metres deep "to be safe" and the living room goes dark in winter. The architect sizes the depth for the actual window height and how far the facade turns away from due south.
West is the hardest side
On summer afternoons the sun comes in from the west, low and almost horizontal, and a horizontal overhang does not stop it. By then walls and air are already warm, and a large west-facing glass wall turns the living room into a greenhouse by six o'clock.
What works: vertical fins, external sliding or pivoting screens, external blinds and awnings, and deciduous trees that let light through in winter. Interior curtains cut glare but not heat: the heat has already come through the glass. Glass with a low solar factor helps, but on the west it is rarely enough without external protection.
Sea views versus the sun
On the hillsides of Castelldefels and the Garraf, the best views often face south or south-west, straight into the afternoon sun. Nobody wants to give up the view for the sake of orientation, and rightly so.
There are solutions. A deep covered terrace in front of the living room, which doubles as a summer room. A pergola with adjustable louvres that close in July and open in January. Splitting the glazing: a picture window towards the view and smaller, shaded side windows facing west. By the sea, movable external systems need salt-resistant materials and motors and regular maintenance, which is worth considering before choosing a model.
Test it against real-life scenarios
A single visit to the plot at midday tells you nothing about how the house will live through the year. Write down scenarios and test each one. Breakfast in the kitchen by the garden: will the morning sun come through the window or into your eyes? Screen work in the study: will there be glare in the afternoon? Dinner on the terrace in summer: will the sun shine in your face until nine? An east-facing bedroom: will you need blackout curtains for the early sunrise?
A pool needs sun for most of the day, and the house's shadow falling on the water in the afternoon is a common mistake. Solar panels need a south-facing roof with no shade from a neighbouring building or trees. If the project has both, as our detached house of 2022 to 2024 did, their placement is decided together with the orientation of the house.
How to check on the plot and in the design
On the plot, record the compass points, the neighbouring buildings and trees that cast shade, and possible future development next door: today's empty lot may, under the planning rules, become a three-storey house. Visit in the morning and in the evening, not only at midday.
In the design, ask the architect for a sun study: how shadows fall at the solstices and equinoxes, in the morning, at noon and in the evening. With a 3D model this takes a reasonable amount of time these days. Windows and shading are chosen alongside it, not separately: a decorative blind at the end of the build will not fix a mistake in orientation.
Mistakes that cannot be fixed later
A west-facing glass wall with no external shading. An overhang so deep the living room is dark in winter. Only interior curtains on the south and west. A pool in the afternoon shade of the house. Panels on the north slope because the terrace took the south one. Motorised external screens by the sea in ordinary metal.
Orientation and major shading can only be changed at design stage. That is why we tie these decisions to the layout, the choice of windows and the facade before the construction quote.