About
About Horizon UAE
Horizon UAE covers one subject: making an outdoor room in the Gulf usable for nine months of the year. Shade, surfaces, planting and light after dark carry almost the whole outcome, and each of the four rewards being treated as an engineering problem with measured inputs rather than a matter of taste.
What climate baseline do the figures on Horizon UAE assume?
Every figure published on Horizon UAE assumes a coastal UAE site at latitude 25.2 degrees north: summer air peaking at 44 to 47 degrees at 15:00 in July, August dew points of 27 to 29 degrees, a solar noon altitude of 88 degrees on 21 June and 41 degrees on 21 December, and roughly 90 mm of rain a year.
| Site | Latitude | Peak air, 15:00 in July | Dew point in August | Solar noon, 21 June | Solar noon, 21 December |
|---|---|---|---|---|---|
| Dubai and Abu Dhabi coast | 25.2 degrees north | 44 to 47 degrees | 27 to 29 degrees | 88 degrees | 41 degrees |
| Al Ain | 24.2 degrees north | 47 to 50 degrees | 18 to 22 degrees | 89 degrees | 42 degrees |
| Liwa and the interior | 23.1 degrees north | 48 to 51 degrees | 15 to 20 degrees | 90 degrees | 43 degrees |
Inland sites at Al Ain and Liwa run hotter by day, drier through August and cooler at night than the coast. Paving and planting figures published here therefore shift in an inland reader's favour on the humidity side, where lavender and rosemary survive that a coastal terrace loses, and against on the peak temperature side, where a 15:00 July slab reading runs 3 to 4 degrees above the coastal range.
Where do the numbers in each Horizon UAE note come from?
Three sources feed the notes, and the text labels each one where it appears. Solar geometry is calculated and exact. Surface temperatures, insect catch ratios and irrigation volumes are typical measured ranges rather than single values. Illuminance and slip limits come from published standards, named at the point of use.
- Calculated geometry: sun altitude, azimuth, shadow length and slat cover are derived from latitude 25.2 degrees north and the date, so those values carry no measurement error. Solar noon in Dubai falls at 12:20 on 21 June and 12:18 on 21 December.
- Typical measured ranges: surface temperatures, root zone temperatures, insect catch by lamp type and irrigation volumes come from field readings commonly reported by installers in the region. Ranges appear instead of single values because wind, humidity and construction depth move every one of them by several degrees or several litres.
- Published standards: illuminance limits at a boundary reference CIE 150, slip values reference wet pendulum testing, and IP ratings and stainless steel grades follow the usual product classifications.
Nothing published on Horizon UAE substitutes for a site specific design by a licensed engineer, particularly for anything structural, anything electrical and anything connected to a swimming pool. The notes are written to make a conversation with a contractor shorter and more precise.
Which units and conventions does Horizon UAE use?
All temperatures on Horizon UAE are degrees Celsius, all dimensions are millimetres or metres, all water volumes are litres, and all times are UAE local time at UTC+4. Colour temperatures use kelvin, light levels use lux, and pot sizes use litres of substrate rather than pot diameter.
Pot diameter is dropped as a unit because two pots of the same 400 mm diameter can differ by half their volume, depending on taper and internal depth, and root zone temperature tracks volume rather than width. Every temperature claim on the site carries the month and the hour it applies to, because a paving figure at 15:00 in July and the same slab at 21:00 in July differ by more than 30 degrees.
Which four notes does Horizon UAE publish?
Horizon UAE publishes four notes, one for each of the decisions that sets whether a Gulf terrace is usable: slat geometry overhead, paving temperature underfoot, root zone temperature in pots, and light level after 19:00. Each note carries at least one comparison table and dates every temperature it quotes.
- Pergola slat spacing that shades a terrace at 13:00 in June: slat width, gap, run direction, and the cover each combination produces.
- Which terrace paving stays under 60 degrees in July sun: surface temperature by material, light reflectance value and build-up depth.
- Which terrace plants survive a Gulf summer in pots: species, pot volume, root zone temperature, substrate and litres per week.
- How much light a terrace needs after dark, and at what colour temperature: lux by task, insect catch by kelvin, glare limits and fixture durability.
Corrections are welcome, particularly measured readings that contradict the ranges published here. A figure that fails on a real terrace in Dubai is more useful than a figure that holds in theory.