Custom Facade Design
PTCC develops new wall and cladding systems, each of which is tailored to meet the aesthetic and performance requirements of a particular building. The facade types that we design include unitized curtain walls, unitized skylights, point-fixed glass walls, lightweight truss-supported glazing, and also claddings.
Curtain Wall Design
World Trade Centre Bahrain

Despite the large numbers of standard facade systems that exist and that are available to every contractor, often the most practical and cost-effective option — particularly if the wall to be constructed is not not flat or rectilinear — is to develop a suite of custom-designed aluminium extrusions specifically for the project. This is the sort of design work in which PTCC specializes. PTCC's technical team devises the functional concept for a new curtain wall system, and then refines the shapes of the new aluminium extrusions and brackets, making use of mathematical optimization techniques to minimize metal weight. We provide die drawings for each of the new framing extrusions and gaskets, and we specify production parameters such at the dimensional tolerance limits. Our experienced staff can monitor the quality of material samples, and give guidance during the fabrication of prototypes and initial testing of a new wall.
Curtain wall prototype fabrication and
A close look at the image reflected in the glass of this mock-up sample reveals the complex, faceted shape of the facade. Using off-the-shelf products it would not have been possible to build a fully-unitized curtain wall in such an unusual geometry. For this project, as for many others, PTCC developed a completely new and custom-designed suite of aluminium framing extrusions.
Nowadays the curtain walls used at the main facades of large buildings are most likely to be of the fully-unitized kind. PTCC has considerable depth of experience in the design of this sort of curtain wall, human experience which can be applied in conjunction with sophisticated computational methods to create well-optimized solutions for your project. At the same time we are adept in the development of stick-system and panel-on-stick wall types, and, whenever there is a requirement for features (such as integrated lighting fixtures, thermal breaks, sunscreens or operable panels) we are ready to offer workable details.
Routinely PTCC creates bespoke designs for exterior wall claddings. The types of facing with which we are most familiar are solid aluminium sheet, composite panel, natural stone and terracotta: we are however always interested to work on projects with adventurous architects who wish to use of more exotic materials.
Amongst the cladding systems developed by PTCC you will find great variety in the design of the concealed components — the structural sub-frames, stiffeners and attachment brackets. For buildings located in developing countries, where site labour is inexpensive, minimization of material quantities is usually the key to lowering the total construction cost. On the other hand, for projects in regions where man-hour rates are high, cost analysis is more complex and the optimal solution may involve the importation of pre-fabricated cladding panels to be attached to the building structure using small numbers of adjustable brackets. At PTCC we understand these commercial pressures and we can help you to formulate technical solutions appropriate for your market.
Grand Lisboa canopy design study

During recent years we have seen that, increasingly, claddings are being applied to irregular-shaped building features. However intricate the geometry, PTCC has the 3D modelling tools and the internal processes needed to document all of the components efficiently.
Grand Lisboa photo
In addition to the design of architectural wall coverings for simple, flat facade areas, PTCC also develops and details cladding for geometrically complex features such as the intricate canopies above. (For those familiar with this particular project, a side note is that PTCC led the design and documentation of cladding for the first of the facade contractors to work on the building's podium.)
Lightweight Rod and Cable Truss Systems
Within the public areas of a grand building there may be an architectural requirement for glazing that is high or wide in span, but unobstructed by conventional structural beams or columns. To satisfy this requirement PTCC is able to design and engineer lightweight truss supports made up of rod or cable elements. If space constraints make it impractical to introduce a truss, or if it is desirable to slow the rate at which the wall responds under transient loading, then we can apply our experience as designers of tensioned cable-net facades.
Horizontal and vertical trusses designed by PTCC
Lightweight truss supports designed by PTCC. On the left is a vertical cable truss capable of resisting typhoon storm conditions, and, on the right, a horizontal rod truss at an aluminium-framed curtain wall in the Middle East.
We develop custom-designed extrusions for use overhead in glass roofs or skylights. Technical requirements vary greatly from one project to another and so, over the years, a number of different "breeds" of skylight system have evolved in our design office: the simplest are extruded veneers that attach to steel members; other types use only aluminium framings, and can be either stick built at site or panelized to allow glazing operations to be carried out in a fabrication workshop. In all of our designs we incorporate internal gutters to collect rain water from the purlins and from the rafters, preventing leaks to the interior of the building. We are familiar with the logistical challenges associated with the construction of long-span glazed roofing high above ground level, so we can offer advice and adapt our designs to suit the chosen installation methodology. We understand the need for features such as smoke-vents and sunscreens, as well as provisions for maintenance access, and we are ready to offer technical solutions.
Veneer type and aluminium-framed skylghts designed by PTCC
Examples of skylights designed by PTCC. Above, at the left, is a veneer-type glazing system applied to a dome-shaped steel shell structure. At the right is a stick-built, aluminium-framed skylight at an airport terminal. The point-fixed glazing below is installed above the main entrance lobby in an historic office building in London.
Whole skylight at One Finsbury Circus

Structural Glass Facades
The last category in this list of the building facade types that are designed in PTCC's office, is the structural glass facade. These all-glass walls, including point-fixed systems, are most often used at the atria or entrance lobbies of large buildings, although PTCC is experienced in the design of all-glass skylights and, in one instance, we designed point-fixed glazing which was used throughout the exterior envelope of a high-rise tower.
Glass fins and brackets at the exterior of an all-glass atrium wall designed by PTCC.
Within the field of structural glass, PTCC has established itself as an originator of new construction techniques and design details (such as the novel structural splice assembly shown below, which allows two parts of a laminated glass fin to be joined using a friction clamp, without placing the lamination interlayer in compression).
Also, after design work for your project is complete, we can give practical advice and assistance during the procurement, testing and installation phases. For example, if custom stainless steel fittings are required then we can provide moulds to be used in the investment casting process, and we can show your site staff how to measure accurately the pre-tension in clamping bolts.
Friction Splice Detail at Laminated Glass
An innovative structural splice detail, for use at laminated glass fins, devised and developed by PTCC.