Estimating Building Costs

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Estimating Building Costs
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Estimating Building Costs
National Museum of Scotland Extension Architect
Benson Forsyth Floor Area 112,803 m
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• Estimating Building Costs

Stratford Station Architect Chris
Wilkinson Floor Area 4000m
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Estimating Building Costs
River Rowing Museum Architect David
Chipperfield Floor Area
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Estimating Building Costs
River Rowing Museum Sto Building K Architect
Michael Wilford Floor Area Unknown
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Estimating Building Costs
Reichstag Architect Foster Partners Floor
Area Unknown
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Estimating Building Costs
Lords Media Centre Architect Future
Systems Seats 140 Reporters and has a
café for 50
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Estimating Building Costs
North Greenwich Station Architect Alsop, Lyall
Stormer 405m long by 25m deep by
32 m wide
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Estimating Building Costs
Innovation in architecture is where estimation
and consequently arriving at or keeping within a
cost budget becomes difficult! Which is of course
what architects frequently do. Most standard
forms of building can be effectively estimated
and budgets arrived at without any initial design
work, because a bulk of similar buildings exist
with which comparisons can be drawn. Budgets for
buildings are set by the client only when they
have a good idea what they want. Many budgets
require some form of investigative work and
outline design prior to arriving at a proposed
budget for a particular building on a particular
site. Setting budgets too high can be just as
bad as setting budgets too low for particular
projects. When they are too high, such as
prestigious projects, innovation in terms of
economy are lost, when they are set too low such
as in the competitive commercial sector they
have disastrous results in terms of quality and
efficiency of process.
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Often buildings are constructed related to cost
and return methodologies and if the return does
not exceed the initial construction costs within
5 to 10 years the buildings are simply not
constructed. There will be an estimated return
per unit, these units refer to car parking
spaces, in a car park, rooms in a hotel and units
of accommodation in housing. Investment
is greater than 1 within 5 years Return Taking
into account inflation and interest rates over
the period Assembling data on building types and
their relative costs becomes an essential
pro-forma for the estimating of commercial
buildings. Assembling and maintaining such
information is time consuming and is usually
carried out by specialist estimators. Utilising
the information correctly can also be difficult
with many pitfalls, as direct comparables are
difficult to find.
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Careful attention needs to be paid to 1
Standardised methods of calculating volume and
area. 2 Identifying time and location factors
and utilising cost indexes to vary! 3 Knowledge
of site and subsurface variable conditions. 4
Site work variables, i.e. access, city, pylons,
sewers. 5 Equipment and furnishing inclusion
variables. 6 Significant mechanical and
electrical variables. 7 None construction
variables, i.e. land-cost, design, financing. 8
Identifying the inclusion of ancillary variables,
i.e. swimming pools, standby generators. This
comparative system of estimation can yield an
estimated cost of almost any building at the
initial design stage if the relevant information
is understood and applied competently. There are
other methods of estimation. Material and
Labour- i.e. brickwork and rate of construction,
number of doors and time to fit , attach
ironmongery and paint Component Budgeting- i.e.
foundations, structure, skin, roof.
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An Example of this Component budget layout is as
follows Preliminaries Substructures Frame Upper
Floors Roof Stairs External Walls Windows /
External Doors Internal Walls
Partitions Internal Doors Wall Finishes Floor
Finishes Ceiling Finishes Fittings and
Furnishings Sanitary Builders Work in
Connection Services Site-works Drainage External
Services Also Listed will be the total cost and
the cost per m2 of floor area
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Any Estimator should be capable of 1 Compiling
and presenting comparative data 2 Preparing
budgets prior to design drawings 3 Contribute to
the design analysis, sequencing and identify
relevant costs 4 Forming component budget
estimates 5 Estimating by units 6 Take off and
estimate in detail by material labour They
should also be capable of providing the following
after the initial designs have been
formulated Provide areas of potential cost
saving Provide areas of potential cost variation-
problems Provide the projects components
budget If the estimator cannot provide these,
lacks vision, is inflexible to change and or
innovation or is incommunicative-- then he
should be immediately sacked and another
estimator appointed who satisfies the
requirements as an integral part of the design
team.
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Continuous estimation of the costs throughout the
design phase is essential as a feedback checking
mechanism for all the processes involved in the
design development. Continuous estimation
throughout the design process is also the only
option acceptable to the client. Estimating is
usually carried out on the basis of competition
within the construction industry. This means that
the prices relate to a competitive tendering
process which will hopefully yield the best
price. However this is not always the case! If
time is of the essence then a negotiated tender
may be sought. This will also be competitive
but the competition between contractors will
take place earlier in the design process, before
full information of the works to be carried out
are available. In these cases it is usual to
negotiate related to a set of unit rates which
are primarily labour and management
rates. Negotiated tenders usually cost more than
competitive tendering, however it may prove to be
financially beneficial if time equals money.
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House for an Architect
Client Graham Phillips Architect Graham
Phillips job architect Simon Whiting
Structural, civil and geotechnical engineer Ove
Arup and Partners Mechanical and electrical
engineer Roger Preston and Partners Quantity
surveyor Davis Langdon and Everest Construction
manager Taylor Woodrow Managernent
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House for an Architect
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House for an Architect
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House for an Architect
Cost specifications Total cost
451,000 Area 286m' Cost per m'
1,576.92 Costs Earthworks, drainage, oversite,
lake excavation 80,000 Steel
frame 16,000 Blockwork
10,000 Specialist glazing
68,000 External render 24,000
Roof coverings 16,000 Mechanical
and electrical 48,000 Internal
fitting out and joinery 105,000
Internal/external paving 18,000
Lake liner 11,000 Borehole
10,000 Construction manager's staff and
preliminaries 45,000
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New Wing to The National Portrait Gallery
ARCHITECT Jeremy Dixon. PROJECTMANAGER
CONSTRUCTION ADMINISTRATOR Bovis Programme
Management QUANTITYSURVEYOR Gleeds STRUCTURALENGI
NEER OveArup Partners MECHANICAL, ELECTRICAL
DRAINAGEENGINEER Ove Arup Partners FIRECONSULTANT
Arup Fire ACOUSTICS CONSULTANT Arup
Acoustics LIGHTINGCONSULTANT Evolution ARCHAELOGIC
AL CONSULTANT Ove Arup Partners MAIN CONTRACTOR
STAGE 1 Wallis MAIN CONTRACTOR STAGE 2 Norwest
Hoist Construction
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• Cost p- m' . of total
• SUBSTRUCTURE 87.67 3.36
• SUPERSTRUCTURE
• Frame and upper floors 228.61 8.75
• Roof and rooflights 129.76 4.96
• Staircases 159.02 6.09
• External walls,window and doors 204.80 7.84
• Internal walls,partitions and doors 128.10 4.90
• GROUP ELEMENT TOTAL 850.29 32.54
• INTERNAL FINISHES
• Wall finishes 115.47 4.42
• Floorfinishes 87.71 3.35
• Ceilingflnishes 36.75 1.41
• GROUP ELEMENT TOTAL 239.93 9.18

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• SUBSTRUCTURE
• FOUNDATIONS SLABS 87.67 m' Pile
  foundations, pile caps and ground beams, lift pit
  and in-situ concrete slabs to ground floor,
  tanked with flexible sheet damp-proof membrane
  underpinning to existing building
• SUPERSTRUCTURE
• FRAME 228.61 m' Top-hung trussed-steel frame
  with stability frames and specialist epoxy
  intumescent casings. In-situ concrete upper
  floors on metal decking. In-situ concrete framing
  to lift shaft and central core area. Timber floor
  to form sloping seating to lecture theatre.
  Structural openings formed in 9OOmm thick
  existing walls to create link between the
  existing building and the new extension. Floor
  removed in basement area and new metal flooring
  installed to new plant room
• ROOF AND ROOFLIGHTS 129.76 ml New motorised
  louvres to existing and new roof lights. New
  rooflight of new central core staircase. Built up
  felt roofing to all flat roofs, concrete paving
  slabs on roof to terraces. Lead pitched roofs on
  plywood to restaurant roof. Renewed lead flat
  roofs over main building including substrate
  repairs. Refurbished lantern roof-lights over
  main building. Safety arrest equipment. Rainwater
  down-pipes and gutters including breaking into
  existing gallery spaces to form openings.
  External brises-soleil
• STAIRCASES 159.02 ml Demolition of existing
  feature 'Blue Stair' central core staircase and
  replacement with architectural steel staircase
  with stone treads and open risers, glass
  balustrades and stainless steel handrails.
  In-situ concrete staircases in new entrance hall
  and in new lecture theatre. Metal staircases to
  miniature room with stone treads. Metal external
  walkways and staircases linking new gantry and
  new extension. Service platforms and walkways to
  new extension. Renewal of existing feature
  staircase at second floor level including mosaic
  and stone finishes. Recreation of an ornate
  balustrade to Holbein landing in main staircase
  including demolition of concrete infill to half
  landing to create double-height space. Cleaning
  and repairing stonework through the main staircase

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• EXTERNALWALLS,WINDOWS AND EXTERNAL DOORS
  204.80 m Cavity construction with facing brick,
  insulation and block inner skin to back of house
  area. New lead cladding on timber and metaI
  framework above main buiIding. Natural stone
  cladding to lift overrun above new central core.
  Fire-resistant glazing to restaurant at high
  level and clerestory level. Window cleaning
  cradle. Removing existing windows and doors and
  filling in openings. Creating structural openings
  with concrete frames in 900mm thick walls to
  connect existing building to new extension.
  Revolving glass door with glazed pass doors and
  screens to main entrance
• INTERNALWALLS, PARTITIONS AND DOORS 128.10 m'
  Oversized hardwood panelled doors to entrances
  between new extension and existing building with
  hardwood frames and linings, high quality
  ironmongery. Glazed and fire-rated screens and
  doors to central core staircase. Painted timber
  flush doors to back of house areas. Metal stud
  partitions with low formaldehyde MDF. Blockwork
  partitions to back of house areas
• INTERNAL FINISHES
• WALLFINISHES 115.47 m Slatted hardwood on
  battens to walls of new lecture theatre. Fabric
  covering on flame retardant inner lining to tudor
  gallery walls and the refurbished second floor
  gallery. Polished plaster to third floor WCS.
  Plasterboard, skim and emulsion to external wall
  linings
• FLOOR FINISHES 87.71 m' Carpet tiles on
  plywood to lecture theatre. Hardwood flooring to
  halls and galleries. Natural stone flooring to
  lobbies and main entrance hall, mosaic to main
  stair landing. Vinyl flooring to back of house
  areas. Acoustic treatment to entrance hall and
  lecture theatre. New mat well and mat to main
  entrance. Screed and paint to plant rooms
• CEILING FINISHES 36.75 m' Acoustic panelled
  suspended ceilings to lecture theatre.
  Self-finish suspended ceiling tiles to restaurant
  kitchen. Suspended plasterboard ceilings skim
  coated and emulsion painted

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• FITTINGS AND FURNISHINGS
• FURNITURE 54.95 m L-shaped display cabinet to
  miniatures room. Seating, curtains, curtain track
  and loudspeaker units and a fitted out projection
  room to the lecture theatre. Fitting out to
  changing room. Cloakroom fittings, motorised
  blinds and general signage
• SERVICEINSTALLATIONS 929.86 m Mechanical
  high quality WCs, above-ground drainage,
  condensate drains, air handling plant,
  distribution ductwork, SMS, new dry risers, space
  heating generally, provision of WC areas to
  restaurant. Lightning protection, leak detection
  systems for rainwater pipes. New gas main for
  high level restaurant. Electrical refurbishment
  of existing second floor galleries, audiovisuals,
  stage lighting to lecture theatre, new
  distribution equipment supplies to kitchen and
  restaurant, fibre optic lighting to galleries.
  Extension of ccTv security and fire alarm
  installations and telephone and data
  installations. Extension of fire alarm system
  including mist sprinkler system. Lift and
  conveyors bank of three passenger lifts to
  central core. Disabled passenger lift renewed in
  main entrance. Disabled lift to lecture theatre
  and mezzanine floor. Escalator from ground floor
  to second floor
• BUILDERS WORK IN CONNECTION 49.76 m
• PRELIMINARIES OVERHEADS
• PRELIMINARIES, OVERHEADS AND PROFIT 15.31 m
• EXTERNAL WORKS
• LANDSCAPING,ANCILLARYBUILDINGS 13,100 Minor
  works to yard at entrance to new extension. Costs
  supplied by Colin Field ,Gleeds

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What information is needed to estimate at an
early design stage
1 The type of building, i.e. what is the use 2
The size of the building usually m 3 The
format of the building, i.e. m on each floor 4
Special features required 5 The quality of
finish sought
The above are prime information requirements to
make an approximate costing based on past
building examples, then utilising the indexes in
spoons for projected building costs and location
in the country. Others which are a bonus are 6
The location, land costs and restrictions 7 The
speed of completion, i.e. accelerated
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What is the process Estimate the size of the
building required in floor area and the building
format in terms of number of floors. You may
have to make amendments to the calculation of
area if you have only estimated usable in terms
of core, primary circulation plant and special
features. Find a series of similar buildings
which have been published in Architectural
magazines over the past 5 to 10 years, obviously
the more recent, and similar the better the
analogy is in terms of cost. Utilise the metre
squared method to estimate how much the proposed
building will cost. Use the indexes published by
BCIS online to vary the price relative to
location factors and the time that the example
was built to the time when the proposed building
will be built.
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64 mill
210 mill


25 Mill
5 mill
6 Mill
110 mill
6.46
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Question Produce an outline cost estimate for the
office building in the handout. Your submission
should show all your workings and your references
to existing buildings and their costs Shops _at_
Ground Level, floors 1-4 are offices, services
are on the roof. Finishes Quality medium,
Structure steel, skin patent glazing
ceramics. To be Built in Central London in 2002
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Area of Shops 2340 m Area of Offices 9360
m Spoons 1999 cost of offices (a) medium rise
AC 1065- 1675 (b) Prestige medium rise AC
1335- 1935 Shops AC 1500-1730 Shops _at_ 1600
2340 3,744,000 Offices _at_ 1500 9360
14,040,000 Total costs
17,784,000
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Surrey 1236.16 m
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M 4 Corridor 1520.22
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Central London 1491.43
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Winchester House 1029.63
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Probable cost variables, for fitted out, Shops
1500 Offices 1100 low spec, cost estimate
13,702,000 Shops 1700 Offices 1500
medium spec, cost estimate 17,784,000
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low spec, cost estimate 13,702,000
medium spec, cost estimate 17,784,000 Assume
4 from 2000 to 2002 Low 14,820,083 Medium
19,235,174