Structural Design and Layout for The Arlington
The structural design and layout of The Arlington's two twenty-storey towers: steel frames around concrete cores on 1.5-metre foundation mats, composite floors and glass curtain wall. It records the floor plate, what sits on each level, and the full apartment schedule (290 per tower, 580 in all, from studios to three-bedroom family homes), along with the lifts, stairs, shared spaces and the measures taken for fire, heat and access.
Overview
The Arlington comprises two residential towers, Tower A and Tower B, each of twenty storeys, standing either side of a landscaped courtyard in District 8 of Bixbus. The towers are identical in structure, floor plan and apartment mix. Tower B is a mirror image of Tower A, so that the living rooms and balconies of both face away from the courtyard and out towards the desert and the river.
Foundations
- Each tower stands on a reinforced concrete foundation mat 1.5 metres thick, poured in a single continuous operation of about 1,200 cubic metres.
- Excavation for each mat was taken to 3.5 metres below grade. The desert ground proved harder than the site survey suggested and needed more work to break out, but tests confirmed its bearing capacity.
- A waterproofing membrane sits under and around each mat. There are no basements: plant rooms are on the ground floor and the roof.
Structure
- Frame: structural steel columns and beams, erected in two-storey column tiers, ten tiers to each tower. About 2,000 tonnes of steel per tower.
- Cores: a reinforced concrete core at the centre of each tower holds the lifts, the two escape stairs, the risers and the service shafts. The cores were climbed on jump-form ahead of the steel and brace the frame against wind.
- Floors: composite slabs of metal decking on the steel beams, with a reinforced concrete topping poured one floor at a time.
- Envelope: unitised glass curtain wall, about 14,000 square metres per tower, with solar-control glass and shaded spandrel panels to cut heat gain. Balconies are steel, hung from the frame and finished with glass balustrades.
- Roof: a concrete roof slab carrying the plant, the solar arrays, the rooftop garden and a shared pavilion.
- Height: about 64 metres to the roof, at a floor-to-floor height of about 3.2 metres.
Floor plate
| Element | Area per typical floor |
| Gross floor area | about 2,000 m² |
| Core (lifts, stairs, risers, shafts) | about 250 m² |
| Corridor around the core | about 250 m² |
| Apartments (15) | about 1,235 m² |
| Walls, plant cupboards and refuse room | about 265 m² |
| Balconies (outside the gross area) | about 180 m² |
Apartments sit around the corridor that wraps the core, so every front door is within a short walk of the lifts and both stairs.
Levels
| Level | Use |
| Roof | Rooftop garden, shared pavilion with gym and multi-purpose rooms, solar arrays, cooling plant |
| Levels 2–20 | Apartments: 15 per floor (1 studio, 4 one-bedroom, 6 two-bedroom, 4 three-bedroom) |
| Level 1 (ground) | Entrance lobby, building management office, mail room, bicycle and storage rooms, electrical and generator rooms, water tanks, refuse room, and five accessible apartments opening onto the courtyard |
Apartment numbers follow the floor: the first two digits are the level and the last two the apartment, so Apartment 1804 is the fourth apartment on Level 18.
Apartment types
| Type | Size | Layout |
| Studio | about 45 m² | Open-plan living and sleeping area, kitchen, bathroom with laundry, balcony |
| One bedroom | about 60 m² | Bedroom, open-plan kitchen, dining and living area, bathroom with laundry, balcony |
| Two bedrooms | about 85 m² | Two bedrooms, open-plan kitchen, dining and living area, bathroom, separate toilet, laundry, balcony off the living area |
| Three bedrooms | about 110 m² | Three bedrooms, open-plan kitchen, dining and living area, bathroom, ensuite to the main bedroom, laundry, balconies off the living area and main bedroom |
| Accessible (ground floor) | about 65 m² (one bedroom) or 90 m² (two bedrooms) | Step-free, with wider doors, a roll-in shower and direct access to the courtyard |
Apartment schedule
| Type | Per typical floor | Levels 2–20 (19 floors) | Level 1 accessible | Per tower | Both towers |
| Studio | 1 | 19 | – | 19 | 38 |
| One bedroom | 4 | 76 | 3 | 79 | 158 |
| Two bedrooms | 6 | 114 | 2 | 116 | 232 |
| Three bedrooms | 4 | 76 | – | 76 | 152 |
| Total | 15 | 285 | 5 | 290 | 580 |
Each tower has 539 bedrooms (1,078 across both), not counting the studios. The mix was chosen to house single workers, couples and families side by side, rather than to build one kind of home for one kind of household.
Vertical transport
- Four passenger lifts and one service lift in each tower, eight passenger and two service in all.
- The service lift is sized for furniture and stretchers and has its own lobby on each floor.
- Two pressurised escape stairs in each core, running from the roof to the ground.
Shared spaces
- Courtyard: the landscaped ground between the towers, with the main pool, shaded seating, arid planting and a walking path leading to a gate at the south end of the site and down to the river.
- Roof: a rooftop garden on each tower, with a pavilion holding a gym and rooms that residents can book for meetings, classes and gatherings, and a small plunge pool.
Safety
- Fire-rated construction throughout, with sprinklers in every apartment and common area.
- Pressurised stairs, fire-fighting lobbies at each level, and emergency power to the lifts.
- Clearly marked escape routes and assembly points in the courtyard.
Heat and water
- The curtain wall, shaded balconies and insulated spandrels keep out much of the desert heat before the cooling system has to deal with it.
- Rare rain is collected from both roofs and the courtyard and stored for irrigation.
Access
- Step-free entry from the courtyard and the street, wide corridors, and lifts to every level.
- Five ground-floor apartments in each tower are built for residents with limited mobility.
