Mass and shade

وَجَعَلْنَا نَوْمَكُمْ سُبَاتًا · وَجَعَلْنَا ٱلَّيْلَ لِبَاسًا · وَجَعَلْنَا ٱلنَّهَارَ مَعَاشًا

“And We made your sleep a rest; and We made the night a garment; and We made the day a time for livelihood.”

Qur’an, an-Nabaʾ, 78:9–11.

A summer day, hour by hour

The typical July and August day on the plateau, derived from the hourly means of the reference climate year for the site of the masseria, touches its minimum at six in the morning and its maximum between one and two in the afternoon; between the two lie eight degrees in the reanalysis and twelve at the hilltop station, and in both cases the night falls below twenty-one degrees for only a few hours.1 It is a regime that asks the mass to do a different job from the one it does at Fez: not to store a night-time cold that does not exist here, but to flatten a modest wave and to shift its crest to the evening, when the house can open again.

Twenty-four hours of July and August: outside, in the courtyard, in the room

Reading. The outside curve is not drawn by hand: it is the July and August hourly mean of the PVGIS-TMY typical year for the site of the masseria (ERA5, local time), with the minimum of 20.6 °C at six and the maximum of 28.9 °C between one and two in the afternoon. The other two curves are a diagram: the shaded courtyard follows with reduced amplitude; the room, behind half a metre of limestone, swings by a few degrees and peaks in the evening. The bands mark the hours in which the house opens (night) and closes (day). What it does not show: courtyard and room are not measurements of the masseria; the orders of magnitude come from the Andalusian courtyards (8–14 °C below the outside on the hottest days: Diz-Mellado et al. 2021, 2023) and from the Alhambra (Jiménez Alcalá 1999). The reanalysis smooths the peaks: the Ragusa station gives maxima of 32 °C and minima of 20.

The masseria already has the main instrument. Rubble-core walls of limestone of great thickness, barrel and cross vaults, high rooms: many tens of tonnes of matter that change temperature slowly and give back late what they have received. The time lag of a limestone wall fifty or sixty centimetres thick is counted in hours, and is enough to carry the inside peak past sunset; the reduction in amplitude does the rest, and thirty-two degrees outside become, inside, an afternoon that can be borne without a machine.2

Proportion decides before the materials

Those who have measured the courtyards of the Maghreb and of Andalusia arrive at the same ranking: the height of the walls that surround them weighs more than the mass, the colour of the walls and the conductivity of the materials, and what has been lost by drawing a courtyard too wide is not recovered with a plaster. The rule a master builder keeps in mind can be put in one line: as long as the walls are higher than the courtyard is wide, the courtyard stays cooler than the outside; as soon as it widens beyond the height of the walls, it becomes warmer. The threshold was verified in the Negev desert by Yair Etzion and taken up for the Moroccan house by El Harrouni’s group; the Seville school, which for a decade has been measuring the courtyards of western Andalusia, gives the degrees — up to 8.4 degrees below the outside in an ordinary summer and up to 13.9 during a heatwave in the courtyards of Córdoba — and recommends, for the hottest climates, height-to-width ratios above three.3

The proportion of the courtyard, the shade the design gives and the shade the awning adds

Reading. Pure geometry at the latitude of the masseria (36.9° N): the model calculates the altitude and azimuth of the sun and the shade the four walls cast on the floor of a rectangular courtyard; the section shows the east–west component, the figure in plan also takes account of the south wall. The initial value, AR = 0.6, is that of a masseria courtyard, wider than it is high: in mid-afternoon in August the walls alone shade less than half the floor. The curve in the second panel gives the shaded fraction through the day; the marks show Etzion’s threshold (AR ≈ 1) and the recommendation of the Seville school (AR > 3). The awning box shows what changes when the shade is given not by the walls but by a sail stretched between the facades. What it does not show: shade is not temperature; but it says why here shade is built instead of being inherited from the design.

The courtyard of the masseria is given and cannot be reproportioned: it is the bagghiu of the Hyblaean masserie, wide because it had to take carts, animals and threshing, surrounded by ranges of one storey or little more, so that the ratio between the height of the walls and the width of the space lies well below one.4 The model shows it: in mid-afternoon in August the walls alone shade less than half the floor, and the courtyard, left to itself, is no cooler than the field. From this follows the practical consequence of this page: here shade is not inherited from the design, it is built, with four devices that add up.

— The stretched awning. Canvas sails stretched between the facades in the middle hours of the day, following the use that Seville and Córdoba have practised for centuries over patios and streets, and that contemporary research has measured: an awning over the courtyard brings a difference of three degrees to more than twelve.5 It works because the hot air escapes between one strip and the next instead of stagnating under a continuous cover; it is mounted on a self-supporting structure, not anchored to the historic masonry, and is taken down in October.

— Climbers. On part of the perimeter walls, deciduous: they shade the masonry in the hours when it takes the sun and leave it bare in winter.

— The perimeter pergolas. They keep doors and windows out of the sun for the whole summer and give, come winter, a dry walk along the courtyard on rainy days: one and the same piece of architecture for the two seasons.

— Trees. Where the subsoil allows and where the cisterns do not run: carob and mulberry, which are the ones the Hyblaean masserie kept in the bagghiu.

The manoeuvre

In winter the mass is charged with heat, and that is the principle of the storage stove and of the heated floor of the hammam, described on the energy page. In summer it is charged with the night. The openings are thrown wide after sunset and until dawn, the sixteen rooflights of the dormitories are opened opposite the courtyard windows, so that the air crosses the rooms instead of stopping at the threshold; then, in the morning, the house is closed — shutters, doors, awning — and is not reopened. The house spends the afternoon on its reserve, and the lag between the peak of heat outside and the one inside is counted in hours.

The manoeuvre: the house open by night, closed by day

Reading. The same section in two states. By night the walls radiate towards the sky and give up the heat they have stored; in the humid air of the Hyblaean coast this loss is smaller than in the desert (under a clear, dry sky 40–80 W/m², much less with water vapour in the atmosphere: Zhao et al. 2019), and that is why here the night is not enough on its own: the house helps it by opening rooflights and windows opposite one another, so that the air crosses the dormitories. By day the house closes and the awning stops the sun before it touches the floor; the strips let the hot air escape. In winter the manoeuvre is reversed. The point for this page: it is a discipline, kept by someone every day of the summer, and it is written in the rules together with the workshop hours.

Night, house open — towards the sky: the cooler, denser air sinks; the mass discharges; rooflights and windows open opposite one another.

Day, house closed — the awning stops the sun, the hot air escapes between one strip and the next; shutters and doors closed; the house lives on the night’s reserve.

All this is a manoeuvre, not an image, and in winter it is done the other way round, opening by day and closing by night. An old house inhabited like a modern one — windows open in the afternoon, closed in the evening — loses exactly the benefit it was built for. It is the first thing the house will teach whoever enters it, and it is the reason why a community that lives in the house all year round has, where coolness is concerned, an advantage that no installation provides: someone who opens and closes at the right hours, every day of the summer, and the rule written in the regulations together with the workshop hours.

The courtyard is readily described as a chimney, in which hot air would rise to leave at the top. It is true at certain hours and misleading as a general description: by night the walls radiate towards the sky and cool, the air in contact with them becomes denser and sinks, and the courtyard fills from below with air cooler than that of the terraces, where it stays stratified until the sun reaches it. In the humid air of the Hyblaean coast this radiative loss is smaller than in the desert, and that is why the house helps the night with the rooflights.6 By day the same geometry asks to be kept closed: multiplying the openings does not make a courtyard breathe better, it lets the hot air in.

What is not built, and why say so

There is another family of solutions, and it is worth saying that no use is made of it. The malqaf, the scoop that catches the wind and brings it down into the house, belongs to Egypt, Iraq and the Levant; the bādgīr, the multidirectional wind tower, to Persia and the Gulf. They answer climates where the night does not cool enough, or where the prevailing winds are regular enough to raise a tower on their axis. On the Hyblaean plateau neither condition obtains, and the masserie of the area never built them: adding one would be a decorative element disguised as technique, and on a listed building it would also be hard to get approved. What Sicily did build, instead, is underground, and has its own page.

What is not promised

These buildings have a documented defect, and it is damp. The mass that keeps the cool also keeps water, and a historic wall that is sealed and heated in the modern manner degrades faster than a wall left to breathe; that is why the restoration acts first on the plasters, the underfloor void and the roof, and why the house will have a discipline of opening and closing instead of an automatic system. Nor is a number promised: the measurements on this page come from Córdoba, from Seville and from the Negev, not from the masseria, and the first real measurement will be its own, under the review of the Scientific Committee the house is setting up.

PVGIS 5.3, TMY typical year (ERA5 and SARAH3, 2005–2023) for 36.93° N 14.73° E, 479 m: July and August hourly means, local time, minimum 20.6 °C at 06:00, maximum 28.9 °C at 13:00–14:00. Ragusa station (515 m), 1991–2019: maxima of 32.3–32.6 °C, minima of 20.2–20.7 °C.

For the order of magnitude of the time lag in massive walls, R. El Harrouni, M. Benaicha, I. M. Benkirane, V. Becue, “Bioclimatic assessment and thermal comfort of traditional Riads in Fez Medina”, Results in Engineering 29 (2026), 108889 (lag ≈ 12 h through rammed earth). For Hyblaean limestone no published measurement exists: the value will be that of the monitoring campaign.

Y. Etzion, “The thermal behaviour of non-shaded closed courtyards in hot-arid zones”, Architectural Science Review 33 (1990), pp. 79–83, taken up in K. El Harrouni, M. Ben Aicha, R. El Harrouni, “Parametric modelling and traditional architecture”, MATEC Web of Conferences 149 (2018), 02051; E. Diz-Mellado et al., Building and Environment 203 (2021), 108094; C. Rivera-Gómez, E. Diz-Mellado, C. Galán-Marín, V. López-Cabeza, “Tempering potential-based evaluation of the courtyard microclimate as a combined function of aspect ratio and outdoor temperature”, Sustainable Cities and Society 51 (2019), 101740.

On the Hyblaean masseria: enclosed courtyard (u bagghiu) paved in limestone, with cistern or well and carob or mulberry; functional cells around it (Ecomuseo CARAT, Ragusa, Le masserie). The proportions of the masseria courtyard will be published with the survey.

On the historical use of toldos in Seville: S. M. Morales Pérez, “El patio y la herencia sevillana del habitar”, Arquitectura y Urbanismo XL/2 (2019), pp. 59–66, which cites Morales Padrón 1977 on sixteenth-century houses. On the measurement: V. P. López-Cabeza, C. Galán-Marín, C. Rivera-Gómez, “Thermodynamic performance enhancement of courtyards using a shading device”, Proceedings 38 (2020), 17; V. P. López-Cabeza et al., “Shade and thermal comfort in courtyards: experimental versus simulation results”, Buildings 12 (2022), 1961.

D. Zhao et al., “Radiative sky cooling: fundamental principles, materials, and applications”, Applied Physics Reviews 6 (2019), 021306: 40–80 W/m² net under a clear, dry sky; water vapour reduces the power, down to about 38 W/m² at night measured in a humid climate.

The Scientific Committee, now being constituted, that will read these measurements is described on the page Air, water and shade.

What the masseria already did, said in today’s language

The targets that follow are not applied to the masseria from outside: they describe, in today’s language, a discipline that the courtyard houses of the Mediterranean kept out of necessity.

Wall mass, stretched awning, pergolas, night/day manoeuvre — 7.3 energy efficiency · 13.1 resilience to climate-related hazards

Lime plasters, underfloor void, roof: restoration before devices — 11.c resilient buildings using local materials · 11.4 safeguard cultural heritage

The manoeuvre written in the rules and taught to whoever enters — 13.3 education and capacity on adaptation · 3.d reduction of health risks from extreme heat

The terms used in these pages are collected in the glossary and the sources on the sources page. The images are studio renderings: the masseria is not yet restored.