More sustainable foundations can be achieved with measures such as:
- Better practice in site investigation and project planning
- Optimised foundation design
- Use of better accuracy in setting out the construction
- Reappraisal of foundation design with testing
- Use of materials with lower embodied energy
(Reynolds et al, 2010)
Grose and Highfield (2009) indicated the new foundation must not harmfully affect the stability of the retained façade. This can be avoided by using cantilever foundation (Cook, 2007: Das, 2016).
4.1 Cantilever foundation
Cantilever beam foundation
Source: (Emmitt and Grose, 2014)
Cantilever foundation is used to transfer the loads from the columns which are to be created next to existing building; in this case standing façade. The purpose of this preparation is to guarantee that the pressure on the subsoil under the existing façade is not so deeply surcharged by the weight of the foundation of the new structure as to cause appreciable settlement (Emmitt and Grose, 2014:Bentler and Labuz, 2006). As shown in the fig, a beam backing the column next to the existing façade; the beam is cantilevered over a stub column so that the foundation is distant from the existing façade and doubtful to surcharge the soil under the foundation.
- Structural frames
A balancing of costs and use requirements, nature and use of the building and the architect’s conception of the finished building will usually give the indication of the most suitable kind of structural frames (Foster et al, 2007).
5.1 Steel frame
Steel structural frames will be used for both buildings for many reasons:
Steel structural frame is efficient, competitive, and makes a significant contribution to the national economy especially after the crises of Tata steel company.
- Both buildings can be rapidly constructed using steel modules and systems that are efficiently manufactured off-site and hence are of high quality and with few defects.
- Low overall environmental impact.
- Steel-frame construction schemes provide flexible spaces, which have the potential to be easily improved and reformed so that the life of the building can be extended by accommodating changes in use, layout and size.
- At the end of the valuable life of structures, steel components can be pulling apart relatively easily. Reclaimed steel products are at this time reused (10%) or recycled (84%) without humiliation of properties.
- Off-site manufacture facilitates less traveling working situations, which, in addition to being safer, endorses stability in the workplace, inspires skills improvement, and promotes good local community relations.
- Speed of erection
- Cheaper than concrete structural frame by 3-5 % (despite steel costs having increased by up to 20% before the steel crises)
(Rawlinson, 2015: Sansom, 2003: the Guardian, 2016: Barry, 2001)
5.2 Steel frame and fire
One of the disadvantages of the steel structure is its weakness against fire. But a number of measures have been established to eliminate or reduce applied fire protection such as:
- The fixing of lightweight concrete blocks between the projections of a steel column (keeping the web cool will offer a 30 minute fire resistance).
- Concrete to be poured between the projections (will offer 60 minute fire resistance). Concrete encasement has the advantage of both providing fire protection and increasing the base fixity.
- Steel frame base connections should be detailed and designed to provide some level of rotational restraint, in order to prevent the sidesway of frames and outwards collapse of wall panels.
- The wall panels must be well linked to each other and to the backup frames so that the outwards collapse of the panels can be prevented.
(Foster et al, 2007: Moss et al, 2009: Sun et al, 2012)
- precast concrete hollow core floor slabs
Precast concrete hollow core floor units (HCUs) are commonly used in multi-storey steel- framed structures where they tolerate on to the top projections of universal beams (UBs). The steel beam is usually designed in bending or isolation from the concrete slab and no account is taken of the composite beam action accessible with the precast units (Lam et al, 2000).
Precast HCUs with opened cores and shaped end
Source: (Lam et al, 2000)
According to Lam (1998) HCUs as shown in the fig, are manufactured up to 500 mm in depth, where simply held spans of 20 m are possible. However, the most common depths are 150-300 mm.
Numerous proprietary units are manufactured, either by the long line slip forming or extrusion methods.
6.1 Advantages of HCUs floors
- Exceptional structural capacity to self- weight ratio, with span/depth ratios of the order of 35 for structure loading.
- The hollow cores account for up to 50% of the cross-section, and therefore a 10 m span floor weighs only 3.5 kN/m2.
- The standard width is 1.2 m; enabling fixing rates of around 2000 m2 per week to be achieved using a four-man gang.
- The ceiling may be painted, while all services are located in a raised floor.
- The floors do not require a structural screed to carry horizontal diaphragm forces due to wind loads, etc.
- The units sit directly on to the steel bearing ledge without the need for wet mortar or other bedding materials.
(Davis et al, 1990: Elliott et al, 1992: Lam et al, 2000)
6.2 Suspended ceilings
Suspended floor layout
Source: (Chudley and Greeno, 2014
Suspended ceilings are selected to reduce room height and offer a decorative surface; also they can be used to make a void and easy access for the services, including the support system of lightings fittings and air vents, improve room acoustics, and improve sound insulation (Bryan, 2010).
6.3 Provision for services in floors
Foster et al (2007) indicate that services can be housed above the structural slab, within its actual width or below its supporting beam and in both cases suspended ceiling is used to conceal the services.
Service openings for the hollow core can be created with a diameter (± 75) depend on the design requirements; this can be created through units after installation by drilling centrally through the cores. Commonly service openings up to 400 mm wide in single standard unit width are allowable subject to satisfying design standards. This should be factory formed (Glover, 2013).
- External walls and claddings
Buildings framed with structural steel are often clad with brick masonry, stone masonry, cut stone panels, or precast concrete (Allen and Iano, 2009). The walls is supported by the loadbearing frame of the building, inform a sense of firmness and permeant.
7.1 Masonry veneer walls
Both buildings external faces will be cladded by masonry veneer curtain walls, except the elevation facing the courtyard for MG building and the elevation facing the vehicle access point in St Peters for MI wing; both elevations will be cladded by glass curtain walls.
Brick veneer wall
In these walls, masonry is often used only as a veneer disconnected from the inner wall features by an air space. The inner wall develops a suitable location for structural components, fenestration and thermal insulation, as well as air and vapour tight assemblies and interior finishes (Allen and Iano, 2009: Wall selection guide, 2011).
Paton-Cole et al (2012) state veneer brick walls normally rely on the properties of a sequence of specific materials or components, such as thermal insulation to slow heat transfer, and air and vapour barriers to control movement of interior air, wind and water vapour.
7.1.1 Advantages of Veneer brick walls
- Durability and aesthetic features
- Similar to actual brick-lined walls
- Lightweight: manufactured from clay and shale
- Lower cost: much less cost than actual bricks
- Better insulation and customization options
7.2 Curtain walls
Curtain walling is certainly a development of the twentieth century. It has no loadbearing function other the carry its own masses and to transmit the wind loads on the surface of the wall to the main framed structure behind (Harrison and Vekey, 1998: Memari, 2013)
Glassing curtain wall
According to Memari (2013) curtain wall is the skin of a building (glass and aluminium structure); its primary function is as separator or boundary between interior and outdoor environments. Curtain wall is light compared with other façades such as masonry and precast, and its name derives from the way it hangs from the structure like a curtain. The curtain glass walls will be used in the elevation facing the courtyard for MG building and the elevation facing the vehicle access point in St Peters for MI wing.
The roof is the primary line of protection against the weather. It can protect the structure from snow, sun and rain. Also it plays a role to insulate the structure from extremes of heat and cold vapour (Allen and Iano, 2009).
8.1 Low-Slope Roofs (Flat roofs)
Flat roofs have been chosen for this project because of many advantages like;
- Can cover building of any horizontal dimension
- Building with low slope roof has a much simpler geometry
- Less expensive to construct
- It can serve as balconies, patios, and even landscaped parks
(Allen and Iano, 2009)
According to Allen and Iano (2009) a low slope roof is a highly collaborating assembly finished up of several components:
- The deck: is the structural surface that supports the roof.
- Thermal insulation: installed to slow the passage of heat into and out of the building
- Vapour retarder: to avoid moisture from accumulating within the insulation
Low-Slope Roofing. Source:
Roof remembrance: impervious sheet of material that preserves water out of the building
- Drainage: mechanisms that remove the water that runs off the membrane
To avoid the disadvantages of flat roofs, Cairns (1996) recommend upgrading specification as follows:
- Strip back to the top of the original concrete planks, and cover with high performance felt, hot mopped with oxidized bitumen.
- Bond extruded polystyrene blocks on top cut into suitable shapes to restore falls, with a hot wire.
- Cover with cork sheets, minimum 15mm thick (break bonded), glued on. (This is available in Scotland as a composite product called “Styrotilt”.)
- Finish with minimum two-layer high performance felt, “partially” bonded or a single membrane system, spot bonded to the cork boards. (Use only polymer-modified adhesive.)
- Ventilate the roof at the peaks of the polystyrene wedges which will now have the effect of introducing mini ridges all along the roof.
- Atrium roof structure
Atrium can be a fairly useful and competent design influence when suitable climate conditions, roof type, and building design are brought together. Heschong and McHugh (2000) have found that when designed with suitable form, atrium in particular help to minimize electrical consumption for lighting while providing ideal lighting conditions. Moreover, atrium is also known to be valuable with concern to energy consumption in relations of heating, cooling, and ventilating.
9.1 PV atrium
Building integrated photovoltaics (BIPV) are frequently seen as one suitable measure to decrease urban carbon emissions through power generation and as an assistance to endorse performance change of inhabitants to contribute to the objective of more sustainable cities. Solar photovoltaics (PV) are often applied as an ‘add-on’ solution to existing building structures in an aesthetically less than pleasing manner, representing a technological and environmental statement but not always a testament to good design (Bahaj et al, 2007). Integration of PV into the courtyard as roofing or shading system will offer additional benefit likes offsetting the cost of high value cladding or providing a function of solar shading.
Atrium roof glazing
Semi-transparent solar shading.
Modulated daylighting effects (dappled light equivalent’ to a tree canopy).
Changing levels of daylight retained.
Visual connection of the building users to the outside.
Visually pleasing daylight effects (standard shading would exclude daylight).
Radiant pane effect can help to drive stack-effect ventilation.
Bespoke shading system can be replaced (potential cost reduction).
Integration very simple (replaces standard glazing).
Solar gain of a fully glazed atrium can be reduced.
Additional glare protection generally not required.
Potential of cost offsetting for high-cost shading. solutions
Low to moderate risk of radiant pane effect due to light absorption of solar cell.
Custom-designed modules have a cost premium.
Accessibility reduced in case of system failure.
(Bahaj et al, 2007)
- Fire protection and escape routes
Fire protection is generally considered to cover both the safety of people and of structure. Fire protection must be included into the design process and synchronised throughout the construction (Stollard and Abrahams, 1999: Lataille, 2003).
The following techniques should be achieved in the design of both MG and MI buildings:
1- Initiation and development of a fire within the enclosure of origin
2- Spread of smoke and toxic gases within and beyond the enclosure of origin
3- Structural response and fire spread beyond the enclosure of origin
4- Detection of fire and activation of protection system
5- Fire services intervention
7- Probabilistic risk assessment
10.1 Buildings layout
New MG and MI buildings layout will meet the basic requirements for life safety such as; occupancy classification per applicable codes, hazards classification per applicable codes and number of occupants to be accommodated.
10.2 Fire hazards
Hazards must be identified that the layout can be planned, also plans must considered the process of chemical hazards, hazards associated with utilities and storage of hazards material during and after the construction stage (Lataille, 2003).
10.3 Detection and alarm system
According to Lataille (2003) there are many features must be considered like:
- Type of automatic detection to be provided
- Building firefighting system to be monitored
- Monitoring of buildings, equipment, process and hazards for off normal conditions
- Transmission of alarm to a central alarm receiving area
- Evacuation of occupants
10.4 Fire protection water supplies
- Location and number of water supplies
- Location, number, spacing and type of hydrants
- Location and sprinkler lead-ins
- Location of control and sectional valves
- Location of fire department networks
- Need for multiple independent supplies for reality
10.5 Special Extinguishing System
- Suitable system for operating the extinguishing system
- Function of the extinguishing system (fire control, exposure system, etc.)
- Extinguishing agent effective for the material that may burn
- Design basic for the system (rate by volume, rate by area, etc.)
- Suitable storage and delivery system
10.6 Escape routes
Escape routes should ensure to be:
- Easy to access
- Adequate for a number of people
- Free from any obstruction, slip or trip hazards
- Available for access by the emergency services
Example of escape route
Source: (Fire safety, 2006)
Available for use by disabled people.
(Fire safety, 2006)
All doors on escape routes should open in the direction of escape, and ideally be fitted with a safety vision panel.
10.7 Mobility impairment
- A refuge is a place of sound safety in which disabled people can postpone either for an evacuation lift or for assistance up or down stairs. Disabled people should not be left unaccompanied in a refuge area for evacuation whilst waiting for assistance.
- Refuge point should be bounded in a fire resistance structure
Source: (Fire safety, 2006)
Construction Industry Research and Information Association defined the buildability as ‘’ the extent to which the design of a building facilities ease of construction, subject to the overall requirements for the completed building’’ (CIRIA, 1983).
Improving the buildability can be achieved through the common three approaches below as Wong et al (2007) satisfied:
- Quantified assessment of buildability in design
- Constructability review
- Implementation of constructability programs
11.1 Areas where the principles of Buildability can be employed
- Improving performance in site productivity, construction quality and reduced labour consumption
- Reducing wastages and inefficiencies during construction
- Promote to use precast concrete for environmental factor instead of in-situ construction and for quality improvement it’s pre-assembly under factory conditions.
- Considering construction difficulties at the design stage to avoid solving problems during the construction stage which lead to project delay.
- The designer has to focus on buildability factors not aesthetic requirements.
- BIM: enhance the co-ordination between all parties (client/contractor/ supplier/subcontractors, etc.).
- The use of alternative procurement approaches enabling early contractor participation in the design stage should be promoted
- Carry out reviews to improve buildability before tenders are invited.
- Constructability reviews and the early involvement of contractors in the design process have also been used with proven success in buildability achievement.
(Lam and Wong, 2008)
- Plans and drawings
See appendix (3) for the below drawings:
- Ground floor layout (rooms) of the new MG Building – walls only.
- First floor (‘The Marble’ level) layout of the new MA Wing – walls only.
- Elevation of the new MG Wing building facing the Courtyard
- Elevation of the new building facing the Vehicle access point in St. Peters Square.
- Atrium cross section in relation to surrounding buildings.
Demolishing of existing building to build a develop ones is a big challenge for both clients and contractors. But as can be seen throughout the above report, the construction technology achieved that within both sustainability and buildability. The focal point is that the technology offers many construction style choices that can be under the footprint of client conditions.
The development construction will achieve the target that has been built for, this will be throughout the design first and the construction materials that has been used. The purpose of the buildings and the climate of the area all have been put into consideration. The structures would be sufficient to carry out the loads, utilize the spaces, aesthetically, highly visible to the public and will fulfil the goal of endorsing motivating environment where large number of people would be able to interact.
Using of advanced construction technology will give the construction industry a lot of trustful, confidence and inspiration.
Allen, E. and Iano, J. (2009). Fundamentals of building construction: materials and methods. 5th ed. Hoboken: Wiley
Arham, A (2003). Intelligent selection of demolition techniques. Ph.D. Thesis, Loughborough University
Atlas (2014). Atlas Copco Looks North. [Online]. [Accessed 20 Feb 2016]. Available at: http://diggersanddozers.com/atlas-copco-looks-north/
Bahaj, A. S., James, P. A., and Jentsch, M. F. (2007) Photovoltaics: added value of architectural integration. Proceedings of the Institution of Civil Engineers. 160 (2), PP. 59-69.
Barry, R. (2001). The construction of buildings: volume 4. 5th ed. Oxford: Blackwell
Bentler, J. G., and Labuz, J. F. (2006). Performance of Cantilever Retaining Wall. Geotechnical and Geoenvironmental Engineering. 132 (8), pp. 1062-1070.
British Standard Institution (2000) BS 6187. Code of practice for demolition. London: BSI
Bryan, T. (2010) Construction Technology: Analysis and Choices. 2nd ed. Oxford: Willey- Blackwell
Cairns, A. H. (1996). High performance flat roofs. Structural Survey. 14 (3), pp. 22-26.
Chimay, A., Arham, A., and Tewedros, F. Selection of a demolition techniques: a case study of the Warren Farm Bridge. Structural Survey. (21) 1, pp. 36-48
Chudley, R. and Greeno. R. (2014) Building Construction Handbook. 10th ed. Oxon: Routledge
CIRIA (Construction Industry Research & Information Association) (2003a). Masonry Façade Retention: Best Practice Guide- Report C579. London: CIRIA
CITB (2013) Guidelines on safe and efficient basement construction directly below or near to existing structures. [Online]. [Accessed 29 Apr 2016]. Available at: https://www.citb.co.uk/documents/about-us/what%20we%20do/devevlopment%20fund%20info/asuc%20basement%20guidelines.pdf
Construction Industry Research and Information Association (CIRIA) (1983). Buildability: An Assessment. London: ClRlA
Cooke, R. (2007). Building in the 21st Century. 1st ed. Oxford: Blackwell
Das, B. M. (2016) Principles of foundation engineering. 8th ed. Stamford: Cengage Learning
Davies, G., Elliott, K. S. and Omar, W. (1990). Horizontal diaphragm action in precast concrete floors. Structural Engineer. 68 (2), pp. 25-33.
Designing Buildings (2014) Façade retention. [online]. [Accessed 29 Apr 2016]. Available at: http://www.designingbuildings.co.uk/wiki/Facade_retention
Elliott, K. S., Davies, G. and Omar, W. (1992) Experimental and theoretical investigation of precast concrete hollow-cored slab as horizontal floor diaphragm. Structural Engineer. 70 (10), pp. 175-187.
Emmitt, S. and Grose, C. A. (2014) Barry’s advanced construction of buildings. 3rd ed. Oxford: Wiley Blackwell.
Filip, R. and Marchand, S. (2012): Temporary works: Principal of Design and Construction. Proceedings of the Institution of Civil Engineers. 165 (4), pp. 329-343.
Fire safety (2006). Risk assessment guide. 1st ed. London: Department for Communities and Local Government
Foster, S. F., Harington, R., and Greeno, R. (2007). Mitchell’s Structure and Fabric: Part 2. 7th ed. Harlow: Pearson
Glover, A. (2013). Precast Flooring. [Online]. [Accessed 01 May 2016]. Available at: http://www.acheson-glover.com/precast/wp-content/uploads/2012/07/flooring.pdf
Grose, C. A. and Highfield, D. (2009) Refurbishment and upgrading of buildings. 2nd ed. Oxon: Spon Press
Harrison, H. W. and Vekey, R. C. (1998). Walls, windows and doors: performance, diagnosis, maintenance, repair and the avoidance of defects. 1st ed. Watford: Construction Research Communications (CRC).
Heschong, L. and McHugh, J. (2000). Skylights: calculating illumination levels and energy impacts. Journal of the Illuminating Engineering Society. 29 (1), pp. 90-100.
Klemencic, R. (2015) Safety and security in the built environment approach. Proceedings of the Institution of Civil Engineers. 150 (3), pp. 99-108.
LAM D. (1998). Composite Steel Beams Using Precast Concrete Hollow Core Floor Slabs. PhD Thesis, University of Nottingham.
Lam, D., Elliott, K. S. and Nethercot, D. A. (2000) Experiments on composite steel beams with precast concrete hollow core floor slabs. Proceedings of the Institution of Civil Engineers. 140 (2), PP. 127-138.
Lam, P. and Wong, F. (2008) Implementing a Buildability Assessment Model for Buildability Improvement. Architectural Science Review. 51 (2), PP. 173-184.
Lataille, J. (2003) Fire protection engineering in building design. 1st ed. Oxford: Butterworth Heinemann
Memari, A. M. (2013). Curtain Wall System: A Primer. 1st ed. Reston: American Societ of Civil Engineering.
Moss, P. J., Dhakal, R. P., Bong, M. W., and Buchanan. A. H. (2009). Design of steel portal frame buildings for fire safety. Journal of Constructional Steel Research. 65 (5), PP. 1216- 1224.
NFDC (2012). Demolition Guidance Note. Hertfordshire: the plant-hire association
Paton-Cole, V. P., Gad, F. E., Clifton, C., Lam, N., Davies C. and Hicks, S. (2012) Out-of-plane performance of a brick veneer steel-framed house subjected to seismic loads. Construction and Building Materials. 28 (1), pp. 779-790.
Rawlinson, S. (2015) Steel buildings remains cheaper than concrete. Proceedings of the Institution of Civil Engineers. 159 (1), pp. 5-5. [Online]. [Accessed 30 Apr 2016]. Available at: http://www.icevirtuallibrary.com/doi/full/10.1680/cien.2006.159.1.5
Reynolds, T., Lowers, F., and Butcher, T. (2010) Sustainability in foundation: a review. The Construction Information Services. [Online]. [Accessed 29 Apr 2016]. Available at: http://www.ihsti.com/CIS/document/294304?PreviousPage=search%253ft%253dcantilever%252bfoundation%2526sqm%253dAllTerms
RitchieWiki (2009). Construction Process: Demolition. [Online]. [Accessed on 20 Feb 2016]. Available at: http://www.ritchiewiki.com/wiki/index.php/Demolition
Sansom, M. (2003). Sustainable steel construction: building a better future. Proceedings of the Institution of Civil Engineers. 156 (2), PP. 81-82.
Sturfe, N. (2005) Eliminating hazardous materials from demolition waste. Proceedings of the Institution of Civil Engineers. 158 (1), PP. 25-30.
Sun, R., Huang, Z. and Burgress, I. W. (2012). The collapse behaviour of braced steel frames exposed to fire. Journal of Constructional Steel Research. 72, PP. 130-142.
The Guardian (2016). Brussels steel summit to seek solutions to crisis. [Online]. [Accessed on 30 Apr 2016]. Available at: http://www.theguardian.com/business/2016/apr/18/brussels-steel-summit-to-seek-solutions-to-crisis-sajid-javid
Wall Selection Guide, 2011. Masonry technical manual. [Online]. [Accessed 01 May 2016]. Available: http://www.masonrybc.org/document/manual/mibc-masonry-technical-manual-complete.pdf
Stollard, P. and Abrahams, J. (1999) Fire from first principles: a design guide to building fire safety. 3rd ed. London: E & FN Spon.
Wong, EW.H., Lam, P.T.I., Chan, E.H.W, & Shen, L.Y (2007). A study of measures to improve constructability. International Journal of Quality & Reliability Management. 24 (6), pp. 586-601
Guanquan, C. and Jinhua, S. (2008). Quantitative Assessment of Building Fire Risk to Life Safety. Risk Analysis. 28 (3), pp. 615-625
Holroyd, T. M. (2003) Buildability: successful construction from concept to completion. 1st ed. London: Thomas Telford.
Thomas, G. and Lloydd, D. (2004). Fire resistance of structural components protecting escape routes. Fire and Materials. 28 (2), pp. 343-353
Tricky, R. and Algar, R. (2007). Building regulations in brief. 5th ed. Oxford: Butterworth Heinemann
Wang, A. J. and Hong, Y. (2015). Raffles City Chengdu, China: achieving a sunlight-influenced design. Proceedings