Every year the Institution of Structural Engineers picks out the most interesting pieces of structural engineering out there, highlighting an aspect of design that tends to get overlooked. Today, it announced its picks for 2014—and they range from an Apple store to an ape enclosure.


Keep in mind, this is just the shortlist; the final winners will be announced later this year. But in a way the shortlist is more fun, since we get to see more projects. Check out a few of the ridiculously cool structures below.

The Apple Store in Zorlu, engineered by Eckersley O'Callaghan


It's no surprise that an Apple store made it onto the list this year, since the company has always focused on using unusual structural details in its stores (for example: glass staircases). This store in Istanbul uses some of the biggest, strongest plate glass around, with absolutely no fixings:

Clear glazed single panel walls with no connections to distract the eye, 10m long by 3m high on four sides, provide an efficient structural form capable of resisting seismic loads, while providing total transparency and architectural purity. The lightweight ultra-thin roof made of CFRP panels (carbon fibre reinforced plastic) seamlessly joined on site, provides a completely smooth uniform soffit while also improving the seismic performance of the whole structure. In such a minimalist project the detailing required particular attention, the result being a total absence of fixings, with the five panels being held together by structural silicone.

Lowther Castle engineered by Ramboll UK


This country home was designed in the 1800s, but was crumbling by the 1950s. Now, it's being converted and infilled to its former glory:

The castle walls were stabilised and the stables converted for visitor centre, café, shop, and holiday flats. Ramboll replaced unsightly external steelwork propping the castle walls with neatly hidden internal strengthening. Considerable structural alterations were needed to accommodate the new uses, all carried out with exemplary care, preserving the 19th century appearance. A good piece of careful conservation.


Fourth Rail Bridge engineered by Pell Frischmann


Painting a complex, historic bridge isn't just about aesthetics—it's also vital for the structure itself. And figuring out how to do it has been a two decade-long process:

Twenty years ago Pell Frischmann were asked to find a solution. They carried out condition surveys, often by rope access, and analysed the degrees and rates of corrosion. Complex computer programmes proved, fortunately, that the bridge was strong enough. Repairs and paint systems were researched and specified, and carried out in weatherproof enclosures whose loads on the structure had to be checked. Finally it is finished and the bridge has a coating that should last for 25 years.


Wilhelma Zoo Stuttgart's Enclosure for African Apes engineered by Weischede, Herrmann und Partner


A ridge-like tensile netting and a faceted concrete viewing structure create an interesting, cave-like setting for viewing apes:

The internal accommodation of the new enclosure for African apes takes the form of an artificial ridge. This reinforced concrete spine building follows and S-shape on plan between groves of trees integrated into the zoo landscaping: with its thermal mass contributing passively to the internal climate control. Its solidity sits in contrast to the lightweight stainless steel mesh of the 2200m2 external bonobo enclosure supported on 13 pylons which also serve as climbing frames for the apes.


Melbourne Star Observation Wheel Rectification Design engineered by Arup


Melbourne's observation wheel opened more than six years ago, but engineers realized that design defects made it dangerous. The process of fixing it fell to Arup:

Arup was subsequently appointed to carry out rectification design services and led the re-design of the new Melbourne Star Observation Wheel, after a forensic exercise to identify the cause of the original failure and decide which elements could be reused. The new Wheel is the largest compression wheel of its type in the world, supporting 21 passenger cabins, incorporating the retained spindle, hub and bearing elements from the original Wheel.


Slipstream, Heathrow Terminal 2, London, engineered by Price & Myers


Getting this huge sculpture to hang from Terminal 2 of Heathrow was no small feat:

Nearly 78m long, and weighing 77 tonnes, this is the longest permanent sculpture in Europe, made from around 32,000 unique, digitally fabricated aluminium, plywood and steel parts. Construction was pre-fabricated throughout with 23 pre-made cassettes, each weighing between 3-4 tonnes, brought to site for installation.


The Miles Stair at Somerset House, engineered by Techniker


The core of this cantilevered staircase is woven from thin steel string:

The design includes an unusual lightweight central core of fine steel strands and beautifully sculpted cantilever treads using ultra-high-performance concrete. The stair connects four levels of the historic building, incorporating 104 treads. The design is based on a traditional stone stair but arranged to spring not from a surrounding wall, but on the central steel mesh tower. It is designed to last for 120 years.


Kai Tak Cruise Terminal Building engineered by AECOM Asia


Hong Kong is a major stopping point for the world's cruise ships, and this terminal was designed to show off the city to newcomers:

The 3-storey structure is 850m long with a floor area of 150,000m2, and is designed using innovative concrete bridge construction methods. The prestressed structures are designed to meet the aesthetic requirements with minimal finishes. In-situ and precast concrete is used throughout with a series of long-span box beams that form the structure and the service corridors.


Footbridge over the Bow engineered by Fast + Epp


Banff is already so beautiful, it's hard for any particular man-made structure to compete. This footbridge is understated visually, but lovely from a structural point of view:

This 80 m clear span footbridge over the Bow River is a new icon for the picturesque and historical Rocky Mountain town of Banff, Canada, that fulfills a one-hundred-year-old plan for a second crossing, while also carrying much needed drainage systems to replace aging ones below the river in this pristine national park. Achieving the minimal slender form in timber was made possible by controlling vibrations with a pair of unique tuned mass dampers that address both walking and jogging frequencies.


S-House engineered by Structured Environment


The multi-leveled home is like no house you've ever seen: It has no continuous floor plates, first of all, and no internal columns:

The S-House is a two storey private house in Omiya, Japan on a site just under 90m2. The floors are arranged as quartered area on either side of the central stair core. The interconnection of the floors at the core provides the principal lateral load resisting system for the building. This allows the corner columns to be designed for axial load only and kept to a minimum dimension (44.6mm in diameter).


Lower Hatea River Crossing designed by Knight Architects


This 869-foot bridge in New Zealand isn't just a sculptural landmark, it's also an operating lift bridge:

The bridge provides a minimum headroom of 7.5m with a 25m wide opening section for taller vessels. The opening section relies on an unusual rolling action and the supports and counterweight have been designed to give a memorable architectural appearance that was inspired by traditional Maori fish hook design.


All images via The Structural Awards.