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Haz for Metal Fixation provides services in the design and production of fixing systems for facade cladding. Design and manufacturing capabilities cover the area of stone cladding, curtain wall, brick facing walls, raincreen walls and secondary structures. Products such as anchors, framing channels, cast-in channels, support & restraint brackets, anchor bolts and various accessories are among the standard productions at the factory. The company’s fundamental objective is to assist and advise its clients in choosing the most suitable fixing systems for their requirements and to provide them with quality production and supply with timely deliveries. The innovative design and production techniques offer practical and economical solutions to solve every possible problem within the scope of fixing applications in facade construction. As a manufacturer of fixing systems to major projects around the world, HAZ Metal has proven its quality and reliability to its clients. The company enjoys ser
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The Value of Optimisation in Façade Engineering and Design
An Overview of the Multiple Variables of Sustainable and Environmental Design of
Building Facades
Real Estate, andArchitectural Design
Developers
Façade Specialistsand Engineers
Perspective and Approach to Sustainable Design of
Facades
and
What is a Building Façade?
A Building Envelope – is the group of components which separate the indoor spaces from the
outdoors. These components include all ‘physical’ barriers such as walls, roofs, windows, doors and
foundations.
The Façade is one of the components of the Building Envelope
Building Envelopeor / Shell
or / Enclosure
Building Structure,
Foundations, Internal Walls, Services…etc.
Exploded View of a One-story house
Source: Building Construction Illustrated - Ching
Conventionally; the Main Functions of a Building Envelope – or ‘Enclosure’– have been:
1.Structural support and load-bearing.
2.Control of inward and outward flow of energy and matter.
3.Aesthetic element of interior and exterior.
Source: J.F. Straube and E.F.P. Burnett. Building science for building enclosures. Building Science Press, 2005.
The Façade is essentially the External Wall Component of a Building Envelope…
Source: Visual Dictionary of Architecture - Ching
What are the Functions of a Building Façade?
Source: Façade Construction Manual – Birkhauser – 2004
The Architects / Developer Conventional View
What are the Sustainability Aspects of Façade Design
and Construction?
The Architects / Developer Conventional View
Heating, Ventilation and Air Conditioning (HVAC) Efficiency
In cold climates, such as that of the UK,Energy Consumption % for Domestic Space Heating
= 25% of total Domestic energy consumption
In other countries with hotter climates such as the UAE, specifically Abu Dhabi, buildings cooling energy consumption had risen from
1625 MW to 4750 MW of power from 1990 to 2007(= avg. increase 11.3% per year)
The Architects / Developer Conventional View
Heating, Ventilation and Air Conditioning (HVAC) Efficiency
…The Energy Conservation Aspects Become Obvious
Through Façade Control of Heat Transfer, HVAC Efficiency, and accordingly, Energy Consumption Efficiency can be achieved.
The Architects / Developer Conventional View
Façade Control Technique:Passive Solar Design
Passive solar design refers to the use of the sun’s energy for the heating and cooling of living spaces. In this approach, the building itself or some element of it takes advantage of
natural energy characteristics in materials and air created by exposure to the sun
The Architects / Developer Conventional View
Façade Control Technique:Passive Solar Design
Passivhaus Design(Example from Hassan Fathy’s Architecture)
The Architects / Developer Conventional View
Façade Control Technique:Passive Solar Design
Multiple Variables Specific to Façade/Envelope Design
The Architects / Developer Conventional View
Façade Control Technique:Passive Solar Design
Due to the complete dependence of Passive Solar Design Techniques on the Unique conditions of each building site; its success
necessitates Optimisation…
Passive Solar Design methods will usually achieve 15% reduction in HVAC energy costs; but usually does not exceed 45%, and anything
beyond would be considered a rare success.
The Architects / Developer Conventional View
Is the Undertaking of an optimum Sustainable Façade subject only to
Passive Design Theories?
Façade Design and Engineering Principles
Façade Design and Engineering Principles
Source: Façade Construction Manual – Birkhauser – 2004
1. Functional Criteria
Façade Design and Engineering Principles
Source: Façade Construction Manual – Birkhauser – 2004
1. Functional Criteria
Heat gains are the obvious functional criterion related to sustainability (thus the use of passive design)…
Façade Design and Engineering Principles
Source: Façade Construction Manual – Birkhauser – 2004
1. Functional Criteria
… but natural ventilation, and natural lighting are also a significant factors in the buildings Energy Conservation scheme…
Façade Design and Engineering Principles
Source: Façade Construction Manual – Birkhauser – 2004
1. Functional Criteria
Again… the concept of multi-variable optimisation is evoked to produce an integrated solution
INTEGRATED SOLUTION
Façade Design and Engineering Principles
Is Energy Conservation the only Sustainability aspect to Façade
Design?
What other Principles Guide the design process that can impact
Sustainability?
Façade Design and Engineering Principles
How about…
•Economy of fabrication and construction?
•Value Engineering and Conservation of Material?•Health and Wellbeing of Factory Workers, Site Labour,
or Construction Site Neighbours?
2. Constructional Criteria(i.e. Fundamental Criteria)
Façade Design and Engineering Principles
Source: Façade Construction Manual – Birkhauser – 2004
Integrated Solution
Façade Design and Engineering Principles
At some point in history, all facades were load-bearers and part of the main building structure…
A Cavity Wall Façade
The systematic separation of loadbearing structure and façade structure
a- External Cladding Leaveb- Air cavity
c- Main Loadbearing Structured- Insulation
Façade Design and Engineering Principles
Loadbearing vs. Non-loadbearing
Vertical Section Showing Façade Leaves
Source: Stone Cladding Engineering – Springer
This separation is an efficient load transfer mechanism that ultimately simplifies façade structure design and reduces material requirements
…an economic and material conserving design.
Façade Design and Engineering Principles
Loadbearing vs. Non-loadbearing
Vertical Section Showing Façade Leaves
Source: Stone Cladding Engineering – Springer
Façade Design and Engineering Principles
Multi-leafed /Multi-layered Design
This separation also allows for multi-layered or multi-leafed construction; which can include:
1.Insulation layers2.Building Services3.Air cavities
Source: Façade Construction Manual – Birkhauser – 2004
Façade Design and Engineering Principles
Ventilated Cavity vs. Non-Ventilated
Façade Design and Engineering Principles
Ventilated and Non-ventilated Cavities
The Cooling Effect of Ventilated Cavity Walls will result in minimization of HVAC / Mechanical cooling costs…
Ventilated CavitySource: Guide for the design, construction and maintenance of natural stone facades - Centro Tecnológico del Granito
Façade Design and Engineering Principles
Ventilated and Non-ventilated Cavities
Non-ventilated facades will retain energy in internal heated spaces in cold climates (air is a natural insulator)…
… thus reducing heating costs
Non-ventilated Cavity
Façade Design and Engineering PrinciplesPrefabrication
Stick-systems vs. PanelisedSource: CMHC - Glass and Metal Curtain Walls, Best Practice Guide
Façade Design and Engineering PrinciplesPrefabrication
Source: Building Construction Illustrated - Ching
In Stick systems (in the case of aluminium curtain walls) all elements are fabricated separately and assembled, installed, and sealed at the construction site…
Façade Design and Engineering PrinciplesPrefabrication
Source: Building Construction Illustrated - Ching
In Stick systems (in the case of aluminium curtain walls) all elements are fabricated separately and assembled, installed, and sealed at the construction site… These systems can be more cost-effective in low-rise or
mid-rise buildings… however:1.Construction is longer, and carbon footprint can be relatively high2.Health and safety of worker, and residents of nearby buildings, are harder to control and maintain.
Façade Design and Engineering PrinciplesPrefabrication
Source: Building Construction Illustrated - Ching
In Panelised / Unitised systems all elements are fabricated and assembled at factories / fabrication facilities…
Façade Design and Engineering PrinciplesPrefabrication
Source: Building Construction Illustrated - Ching
In Panelised / Unitised systems all elements are fabricated and assembled at factories / fabrication facilities…
These systems can be technically demanding, however:
1.Construction is much shorter, and carbon footprint is minimized2.In the controlled environment of a factory, Health and safety of workers is easily maintained, and impact at construction site is minimized.
Façade Design and Engineering Principles
Non-loadbearing facades do not transfer weight of the main building,
but they have to carry their own weight, and weight of incident
loads (wind, earthquakes…)
Façade Design and Engineering Principles
Structural Steel, Stainless Steel and Aluminium Alloys Framing and Brackets, are almost exclusively used for the Façade's structure
Façade Design and Engineering Principles
Structural Steel, Stainless Steel and Aluminium Alloys Framing and Brackets, are almost exclusively used for the Façade's structure
Façade Design and Engineering Principles
Structural Steel, Stainless Steel and Aluminium Alloys Framing and Brackets, are almost exclusively used for the Façade's structure
Façade Design and Engineering Principles
Structural Steel, Stainless Steel and Aluminium Alloys Framing and Brackets, are almost exclusively used for the Façade's structure
Façade Design and Engineering Principles
3- Structural Principles
Source: Façade Construction Manual – Birkhauser – 2004
Façade Design and Engineering Principles
3- Structural Principles
How is the Façade Material ‘coupled’ to the main structure?
What are the structural considerations?
What are the methods of fixation?
Source: Façade Construction Manual – Birkhauser – 2004
Integrated Solution
Façade Design and Engineering Principles
Source: Façade Construction Manual – Birkhauser – 2004
The geometry / configuration of fixing elements:
Which is the safest and most cost-efficient, and least material consuming?
a. Over entire surfaceb. Linear, vertical framingc. Linear, horizontal framingd. Linear, Peripheral framinge. Discrete (brackets)f. Multiple Discrete
Façade Design and Engineering Principles
Source: Façade Construction Manual – Birkhauser – 2004
How will the façade structure react to different loads?
Façade Design and Engineering Principles
Stresses Induced:
A 10 mm diameter steel wire rope has a breaking load of 5 tons of force when loaded in
Pure Tension
A much larger section will be required to carry the same
forces in Compound Loading (bending, torsion…etc.)
Façade Design and Engineering Principles
Stresses Induced:
Optimised Solutions can reduce the section size by carefully studying and adjusting the loading mechanism…
Thus, creating design with minimal material consumption…
Façade Design and Engineering Principles
Source: Façade Construction Manual – Birkhauser – 2004
The Movement of Fixing Elements:
Façade Design and Engineering Principles
The Movement of Fixing Elements:
Facades must allow for vertical movement, to account for earthquakes, or thermal expansion…
The location of movement might seem logical in the top (Standing Façade) and the other solution (Suspended Façade) will seem counter-intuitive.
Source: Façade Construction Manual – Birkhauser – 2004
Sliding
Sliding
Fixed
Fixed
Façade Design and Engineering Principles
The standing façade creates what is called a column effect, which induces additional loads in compression (buckling loads) and requires bigger sections, therefore more material is consumed
The suspended façade is loaded in tension only, requires a smaller section, less material, and is more efficient…
Source: Façade Construction Manual – Birkhauser – 2004
Sliding
Sliding
Fixed
Fixed
An Example of Combined Principles / Multiple Variable
Optimisation
Visualization of Thermal Loss Computer Simulation of the Bracket
Thermal Loss Rate Differentials Graph of the Bracket
Thermal Bridging of Brackets/Supports
Sources: www.halfen.de
Structural Thermal Bridging occurs when structural elements penetrate the envelope creating discontinuities in the thermal insulation creating a path for heat loss (in case of heated internal spaces), or heat gain (in case of cooled internal spaces)
An Optimised design is made to:1.Prevent thermal bridging2.Improve structural performance3.Reduce cost and material consumption
Sustainability of Steel
How does Steel fare against other construction materials in terms of
Sustainability?
Sustainability of Steel
Metals / Alloys in general have high Strength-to-Weight Ratios, in comparison to other construction materials
Example:Concrete =Steel =
This means less material for the same structural performance
Steel is also one of the cheapest metals for its strength
Sustainability of Steel
Steel is completely Reusable or Recyclable after the end of a building's life-cycle
And almost 0% waste in fabrication, with all scrap being recyclable.
Sustainability of Steel
Steel is fabricated, treated, coated, welded, assembled offsite in controlled factory conditions, with minimal risk of impact in terms of Health and Safety to the workers
The Value of Optimisation
The Value of Optimisation
Design By Routine vs. Optimum Design
Source: Optimum Design of Steel Structures
The Value of Optimisation
Design By Routine vs. Optimum Design
Design without goals, objective functions
Fulfilling design constraints can only be approximate
Minimum material consumption or cost is not reached
It is impossible to develop new, innovative structural types
Source: Optimum Design of Steel Structures
Exact formulation of Design Problem and goals or constraints
Inclusion of all engineering aspects
Consideration for fabrication/cost aspects
Can achieve significant cost savings in design stage
Allowing designers to innovate, and create competitive designs
Thank you…