Archive for December 12th, 2010

December 12, 2010

Smashing Trends: the Wonder of Glass

Unlike steel and concrete, glass is a relatively new material in the construction sector. Romans began using glass for architectural purposes by casting windows in around AD100, but it wasn’t until the latter part of the Industrial Revolution that scientific research started to reveal the exciting functions and properties of glass.

For a long time, glass was cast in buildings for the sole purpose of letting light in and keeping the weather out. It was widely believed – and is still to an extent – that too much of the transparent material wouldn’t be strong enough to guard a property from vandalism and destruction; it wouldn’t be sturdy enough to withstand a hurricane; and is too transparent to protect a building from heat gain.

Fortunately for the industry and consumers, designers, engineers and scientists are quickly discovering new technologies that are proving the skeptics wrong.

Balancing act

One of the most obvious functions of glass is its ability to open up views and welcome natural light into a building.

For this reason, buildings with greater visual transparency than ever before are beginning to rise, with some curtain walls made almost entirely out of glass. The spherical headquarters of construction giant Aldar in Abu Dhabi, UAE, for example, has an envelope made up of 25,000m³ of glass.

But one major problem with implementing so much glass in warm countries is the amount of heat that builds up inside buildings as a result, and the ultimate rise in air-conditioning costs.

“One of the most obvious functions of glass is its ability to open up views and welcome natural light into a building.”

The easiest solution is to reduce the amount of glass used in construction, which is exactly what the city of Abu Dhabi, UAE is doing.

The capital’s Department of Municipal Affairs plans to issue new building regulations next year, which would mean that glass will make up just 30% of a building’s façade. But this proposed code has caused controversy among architects.

Stride Treglown’s Abu Dhabi general manager Nathan Hones says that the plans discourage creative ideas. “What we should be looking at is a performance-based approach which still requires the designer to address the sustainability issues at hand, but also allows and encourages innovative thinking and solutions to meet these requirements.”

So how can we build sustainably without hindering designers’ work? “Solutions include sun-shade devices, light wells, high performance low-e glass, and double or triple glazing,” says Hones.

US-based RTKL principal and architect Douglas Palladino agrees. “High performance coatings are being increasingly used for glass so we can have the benefit of daylight without the negative effect of unwanted solar radiation.”

One project that has incorporated both an attractive and energy efficient glass façade is China’s Hong Kong Science Park. This development incorporates a double-glazing curtain wall system and sunshades, as well as window units integrated with power-generating photovoltaic panels.

Robert Stephens, Middle East regional director of Inhabit Group, which worked as an engineering consultant on the Science Park project, believes that architects need to understand where the limitations lie when it comes to designing with glass. “It’s kind of a balancing act. Obviously, the more light you let into a building, inherently the more heat is associated with that, but there are coatings available with high thermal insulation properties which don’t detriment visual performance.”

Breaking records

It’s a scientific fact that the molecules that come together to form glass are arranged randomly, which explains why the material is so fragile.

“Despite its fragility, the use of glass in construction is becoming increasingly popular.”

Because of this, the health and safety risks associated with using glass in construction are much higher than when steel or brick is used, explains Stephens. “Steel is a homogenous material and before it snaps it bends. If you take glass, it doesn’t deform before it breaks. There will not be any signs of failure when it comes to glass; it will suddenly just give.”

Despite its fragility, the use of glass in construction is becoming increasingly popular. Nowadays it is even being used as a structural material.

The Willis Tower in Chicago, the tallest building in the US, has an observation deck made entirely out of glass and sits 412m above the city.

In theory, the glass should break when a person steps onto it, but Ross Wimer, design partner for Skidmore, Owings and Merrill (SOM), the firm which designed the deck, explains why this is not the case.

“Three layers of glass, bonded together, make up the walls and floor of the observation deck platform. The laminated glass can support the weight of an elephant, which is reassuring since this glass floor is 1300ft in the air,” says Wimer.

Another project where glass has been used as a structural material is the Apple Store on 5th Avenue, New York. Designed by Bohlin Cywinski Jackson and structural engineers Eckersly O’Callahan, the 9m structural glass cube houses a transparent glass elevator wrapped by a circular glass stair. The store occupies the underground retail concourse, with entry from the plaza level above.

“A challenge faced by many designers, however, is using inner layers to create strength without distorting the glass.”

A challenge faced by many designers, however, is using inner layers to create strength without distorting the glass.

Wimer explains that it’s all about sizing the thickness of the glass to minimise deflection. “Deflection causes distortion or ‘pillowing’ that is particularly apparent if the glass has a reflective coating.”

“One needs to pay particular attention to the jointing and supporting structures to ensure that these do not detract from the transparent character of the glass surface. Thankfully there have been some amazing advancements in jointing material and mullion supports, not to mention the use of glass structurally itself which have overcome any detrimental effects of the limit on the glass panel sizes,” adds Hones.

Low iron-glass also minimises green tint, which appears when layers of glass are made thicker, as Palladino explains. “We use this for visual appeal in lower portions of buildings where there is retail space. There are also low reflection coatings in glass that you use in retail so you can achieve even greater visual transparency.”

Glass in buildings isn’t always transparent, however. Some designers are using technology to create visual interest in what would otherwise be a repetitive curtain wall, according to Palladino. “The desire for nothingness in glass from a design perspective is only one way we approach the use of glass. Often we use it for its physical presence and its material quality. We have designed the Changsha Xin He Delta, a 45-storey building in China that uses different colours of glass to create visual patterns.”

Hazy future

Despite its lucid appearance, the future of glass in construction is not so clear, says Stephens. “Even the codes we are working with at the moment are contradictory, depending on whether you follow an American code or an Australian code. With steel, the codes are all consistent. A lot of the time, with glass, we are not even following the codes 100% because they are trying to catch up with the industry.”

“Glass is being researched today and there are conflicting views surrounding it. It is not fully understood even today,” he adds. But the fact that there are still undiscovered glass techniques is a sign of exciting times ahead for architects and contractors alike.

As Palladino says, “It’s a timeless material and people are using it more because of the way it’s evolving.”

Hones adds, “The industry has developed some very talented facade engineers and glass material supplier specialists who are always at hand to assist the design team with challenging projects. Working with glass is always interesting and one quickly realises how much one doesn’t know when trying to push the boundaries.”

RTKL principal and architect Douglas Palladino.

Changsha Xin He Delta, China: a 45-storey building designed by RTKL, which uses coloured glass to create visual patterns.

Inhabit Group regional director, Middle East Robert Stephens.

Skidmore, Owings and Merrill design partner Ross Wimer.

The glass cladding at the Infinity Tower in Dubai, UAE underwent pressure, suction and destruction tests before it was installed.

The Skydeck Ledge at the Willis Tower in Chicago, US is made entirely out of glass and can support the weight of an elephant.

The Windsor Building at the University of London, UK was designed with an angular glass curtain wall.

December 12, 2010

One Hyde Park Residential Development, London, UK

One Hyde Park is a luxurious modern residential development in the heart of Knightsbridge, Central London, UK. The development consists of 86 apartments and three boutiques. The apartments are being built on the former site of Bowater House, constructed during 1950s.

Designed by Rogers Stirk Harbour + Partners, the development has won several design awards including Best Apartment London and Best Interior Design at the UK Property Awards in 2007 and the Best Luxury Home at the Evening Standard Homes Awards.

The development includes 65,000m² of residential and retail space. Construction on the project began in 2006 and is due for completion in December 2010. The project’s developers expect the penthouse of One Hyde Park to be priced at £100m.

One Hyde Park structure and design

The design consists of four elongated hexagonal blocks or pavilions interlinked by transparent circulation cores such as lobbies, lift shafts and stairwells. The pavilions are designed to maximise the perimeter spaces for each building. The gaps between the pavilions will allow natural sunlight and provide a visual corridor between Knightsbridge and Hyde Park. The buildings have been designed to integrate with the existing neighbouring buildings.

The length and width of the pavilions, and the distance between the buildings and residential cores, were predetermined by the availability of the redefined site.

“One Hyde Park was designed by Rogers Stirk Harbour + Partners.”

The design allows principal rooms in the north and south ends of the development to have a panoramic view of the surroundings.

Secondary rooms are located towards the centre along the perimeter. Tertiary spaces that require less light are built in the central wider parts of the floorplates.

Pavilion architecture

The heights and compositions of the pavilions follow a radial pattern. They rise in two-storey steps – from ten storeys on the west side, 14 storeys at its peak, and 12 storeys on the east. The circulation cores at the ends and between the pavilions provide primary and secondary access.

The pavilions are divided into three zones. The top of the building uses flat and neutral greys, while the middle zones will have privacy screens of red and brown patinated copper. The lower levels will be similar to the surrounding stone plinths buildings with exposed white concrete structural columns. The external structures of the pavilions are made from pre-cast concrete with a mixture of crushed limestone and mica to give a light reflecting quality.


The façade is covered with insulated solid panels for energy efficiency. The red weathered steel panels of the façade will reduce glazing and absorb heat during the summer. The façade is covered with privacy screens consisting of vertical blade-like elements within the outer pre-cast concrete frame which will provide privacy, solar-shading and security. The blades are made of corten steel for colour blending with the immediate area.

The walls are built with pre-weathered zinc panels and glazing areas to emphasise substance and solidity.


Westminster City Council granted permission to demolish Bowater House for the construction of One Hyde Park in June 2006. The demolition began in July 2006 and was completed by December. A top-down construction method was used in order to reduce time. The approach allowed the construction of the superstructure simultaneously with the four-storey basement. The method was beneficial because it was less disruptive than traditional bottom-up construction methods.

“One Hyde Park includes 86 apartments
and three boutiques.”

The substructure construction works of the apartments began in January 2007. The construction of the superstructure began in April 2008 and was completed in 14 months. The core structures between the pavilions are made of steel components with a bolt-engineered design. The entire project, including construction and landscaping, is scheduled for completion in December 2010.


The apartments of One Hyde Park will have communal spas, a private wine-tasting facility and squash courts. Covered garden spaces will be created inside the building. Car lifts and a loading dock area with two truck lifts will be provided. The apartments will also have panic rooms and emergency exits leading to the Mandarin Oriental Hotel. There will be car parking spaces for 139 cars and 114 bicycles. Three retail boutiques will be situated on the ground floor.

One Hyde Park financing

In November 2007, Europe’s real estate and public finance bank granted £1bn debt financing to site owners Project Grande Guernsey (PGGL) for the development of One Hyde Park. PGGL is a joint venture between Guernsey-based CPC Group and the Qatari Prime Minister, His Excellency Sheikh Hamad bin Jassim bin Jabr Al-Thani. The total cost of construction of the project is £250m.

Key Data:

Project Type: Residential Apartments
Location: Knightsbridge, London, UK
Total Area: 65,000m²
Estimated Investment: £250m
Client: Project Grande (Guernsey) Ltd.
Architect: Rogers Stirk Harbour + Partners
Main Contractor: Laing O’Rourke

Key Players:

Client: Project Grande (Guernsey) Ltd.
Architect:Rogers Stirk Harbour + Partners
Main Contractor: Laing O’Rourke
Interior Design and Development management: Candy & Candy
Structural Engineer: Ove Arup & Partners
Services Engineer: Cundall
Cost Consultant: Gardiner & Theobald
Project Manager: APS Project Management
Planning Consultant: DP9
Fire Consultant: Warrington Fire Research Consultants
Landscape Architect: Gillespies
Lighting Design: James Turrell
Suppliers: J&P (T-Bolts and Jordahl channels), Fläkt Woods (HVAC system), Cundall (shell and fitout design, sustainability and IT strategies)

Project Timeline:

Westminster City Council approval: June 2006
Bowater House Demolition: 2006 (July to December)
Construction Started: January 2007
Project Completion: December 2010