Keeping the balance

Keeping the balance

Case Studies

KEEPING THE BALANCE BETWEEN OLD AND NEW

Simon Gregory, Sales Manager at Proteus Facades, looks at how the latest rainscreen cladding materials provide architects with the ability to create striking new structures that sit harmoniously alongside historical and listed buildings.

“Rainscreen cladding has been around for centuries and is now specified on most major developments. The enduring appeal of cladding panels is due to a number of factors, including that fact that there is now a vast choice of materials and finishes. These allow architects to push the boundaries when it comes to designing external façades by either making a harmonious link with older, more historical buildings, or creating a contrasting, distinctive building with its own identity.

When most people think of modern facades they picture the steel and glass rainscreen cladding systems so often found in our city centres, however architects are increasingly looking to use more authentic and traditional materials. This is particularly the case when it comes to designing new structures that are to be built alongside historical and listed buildings.

There are thousands of buildings across the UK that are protected by English Heritage listings or which present some other element of architectural interest. Historic England’s Heritage Protection Guide states that when considering any planning application that affects an area of special architectural or historic interest, a local authority must pay special attention to the desirability of preserving or enhancing the character or appearance of that area. As such, when new buildings are being developed adjacent to these, architects often have to ensure that they can co-ordinate with and complement the rich heritage of the area.

Aesthetic performance

An increasing number of architects are therefore choosing to integrate cladding into their designs, particularly when working on the structures near to listed buildings, due to its aesthetic and performance benefits. In addition, it enables the use of traditional materials such as copper and its alloys, a material that has been used on buildings for centuries.

Bronze, an alloy of copper and tin, remains a popular choice on these kinds of structures because it looks stunning from the day it is installed and then continues to develop and embellish its aesthetic qualities by taking on subtle earthy brown-red to brown-grey tones through the natural weathering process. It provides the façade with outstanding mechanical abrasion and corrosion resistance properties that mean it is one of the most durable cladding materials to use on campus.

Royal Holloway

The new Emily Wilding Davison Building at Royal Holloway, University of London’s Egham campus, is a great example of a new development that has been designed to perfectly complement a nearby listed building, through the use of copper rainscreen cladding.

The east side of the striking 10,000m2 building features the beautiful brown-red to brown-grey and ochre tones of our TECU Bronze cladding panels. The subtle colour variations of the bronze façade helps it sit harmoniously in a site steeped in history, flanked on one side by the Grade I listed Gothic Revival building and surrounded by one of the most beautiful natural campus landscapes of any university in the world.

TECU Bronze cladding was selected by the designer, Associated Architects, because the ochre’s, browns and reds resulting from the natural weathering of the copper alloy material was considered to complement the colour of the brick and clay roof tiles of the adjacent grade I listed structure.

The size and shape of the bronze cladding panels featured heavily during the design stage, with a decision taken to go with elongated portrait format panels with horizontal joints that aligned with projecting feature ‘tree-house’ meeting pods. The sensitive design response came out of a number of constraints imposed by topological aspects of the site, with one principal factor being a need to limit the height of the new building so that it remained clearly subservient to the listed Founders Building.

In response, the Emily Wilding Building doesn’t exceed three storeys above ground, whilst use of the Bronze cladding panels avoids the façade appearing squat. A basement floor was excavated into the sloping site, maximising the useable space.

The Bronze panels, which we supplied in its natural warm, reddish brown state, develops in a manner characteristic of this age-old material through the effects of weathering, providing the façade with outstanding mechanical abrasion and corrosion resistant properties as well as being maintenance free.

Imperial College Molecular Science Building

Another copper alloy that has the ability to sit harmoniously alongside architecturally significant buildings is TECU Brass, an alloy of copper and zinc, which again creates an extremely tough, robust façade. Brass will subtly change from its initial golden colour as a result of the natural weathering process to a develop a matt finish on the surface before taking on a subtle and varied brown tone that continues through to a deep, rich dark brown-anthracite.

In order to shorten the timescale for achieving the subtle muted tones, specifiers can select pre-patinated options. This is where the oxidised layer is applied before the cladding panels arrive on site, bypassing the gradual development of the earthy tones through natural weathering resulting from exposure to atmospheric conditions once the façade is installed.

A great example of the stunning visual effect that can be created by specifying brass with a surface treatment can be seen at Imperial College’s new Molecular Sciences Research Hub at Imperial College in London, designed by Aukett Swanke. We supplied perforated panels in brass with a Capisco patinated finish to create a dynamic aesthetic that visually elevates the flat bare concrete façade and glazed elements.

Summary

Building alongside or near to listed and architecturally significant buildings, like Royal Holloway, must be considered carefully. Clients, architects and developers devote a considerable amount of time to preserving the building, including its setting alongside features of special architectural or historic interest which it possesses.

Façade manufactures have responded to this by introducing traditional cladding materials such as copper, bronze and brass that provide the natural, weathered aesthetic, but offer all the benefits of a modern rear ventilated rainscreen cladding system.

Many university campuses across the UK include older and often listed buildings, however as more young people choose to go into higher education, there is a need to expand and build new to accommodate these growing numbers. However, it is important that they stay in keeping with their surroundings.

The choice of materials used for these new buildings, particularly for the external façade, are therefore critical to this and copper, along with the copper allow of brass, bronze etc. remains one of the most traditional, yet versatile, attractive and adaptable architectural materials available. It has been used for centuries for roofing, cladding and rainwater systems and remains as sought after today as it always has been. Recent innovations in how the material is presented now makes its benefits even more accessible to a wider range of projects. Particularly when working on developing new structures to sit alongside historical and listed buildings, such as those situated at the University of London.”

For more information on Proteus SC visit: www.proteusfacades.com.