Design Economics Flashcards
What is the difference between an order of cost estimate and a cost plan?
A cost estimate is prepared earlier on in the design process typically between RIBA Work Stages 0 to
Stage 2.A cost plan is produced typically at each RIBA Work Stage from Stage 2 onwards.
What is the difference between cost and price?
Cost is the total price of labour, plant, materials and management deployed for a specific activity.
Price is the amount a purchaser or client will pay for an item or product and is made up of the cost plus the main contractor’s profit margin.
How do you proceed if the cost plan exceeds the project budget?
Analyse the costs to assess the source of the increase and identify whether any element of work is abnormally high against the cost estimate.
When the reason for the overspend is identified I would then look to propose value engineering options to my client and design team to bring the forecast back in line with the project budget.
What is buildability?
Buildability is harnessing the contractor’s expertise and knowledge during the design stage to generate
ideas for effective and efficient methods of construction
What are the advantages of buildability?
Buildability can result in better programming, sequencing and construction methods.
* A quicker more efficient programme can be achieved.
* Reduced capital and life cycle costs of the building can be obtained.
* The quality in the finished building’s performance and maintenance characteristics can be improved.
What is a wall to floor ratio?
- This shows the relationship between the wall area and floor area.
- It is used to show the cost efficiency of the building.
- The lower the ratio, the cheaper the building is to construct as there is less external envelope to
construct in comparison to the floor area
What is the most efficient shape?
In theory a building with a circular floor plate building would offer the most efficient design as there is
less wall to floor area.
* However a circular floor plate has a poor lettable floor area and is difficult to fit out therefore a square
floor plate is considered to be the most efficient
How would you prepare an estimate for M&E works?
- I would ask an M&E specialist surveyor to undertake the estimate.
- For feasibility estimates the M&E amount would be included in the m2 or functional unit rate.
What is a section 106 agreement?
S106s are agreements between local authorities and developers that are negotiated in the context of
granting planning consent.
What is construction to ‘shell and core’?
Shell and core is the basic structure, services and envelope of the building.
* This normally includes the fit out of landlord and common areas for example the reception, toilets, lifts
& stair cores.
* Base services are typically terminated at entry points to each of the lettable floor plates however life
safety services infrastructure is normally provided.
What is a CAT A fit out?
- CAT A is also known as a ‘developer’s fit out’.
- This provides generic fit-out items to suit most developers for example life safety elements and basic
fittings such as suspended ceiling tiles, raised floors, carpets, lighting and power distribution to floor
plates
What is a CAT B fit out?
- A CAT B fit out overlays the CAT A provision with bespoke elements that are specific to the needs of
the building’s user to enable the tenant to occupy and use the space. - This would typically include partitions, power distribution to floor boxes, data cabling, artwork and
branding, upgrading CAT A finishes and toilet finishes.
Where could you find the definitions for these?
The British Council of Offices (BCO) fit out guide
What is BWIC?
Builders Work in Connection and is usually set as a percentage of the services cost.
BWIC accounts for the Main Contractor to perform any drilling, fixing, cutting and penetrations to
enable the services installation.
What is an order of cost estimate?
- Under NRM this is described as the determination of the possible cost of a building early in design
stage in relation to the employer’s fundamental requirements. - This takes place prior to preparation of a full set of working drawings or bills of quantities and forms
the initial build-up to the cost planning process
What is the purpose of an order of cost estimate?
- To establish if the proposed building project is affordable and, if affordable, to establish a realistic cost
limit. - The cost limit is the maximum expenditure that the client is prepared to spend on the proposed
building project.
What is the format of a feasibility estimate or order of cost estimate?
- This can be presented on a cost per m2, functional unit or elemental basis.
- It may also be presented as a range for example £700-£850/m2.
- This may consist of element rates for the main elements of the building for example Substructure,
Frame, External Walls, Upper Floors & Roof. - Any site abnormal costs or enabling works are also considered.
- Other inclusions are Preliminaries, Contingency, Inflation and location factor adjustments
What is a functional unit? `
- A functional unit is a unit of measurement that considers the prime use of the building.
- For example in the construction of a hotel or hospital the functional unit may be presented as a cost
per bedroom or cost per bed. - In a retail estimate the functional unit would be presented as the net lettable retail space.
Where would you get your rates from for a preliminary estimate?
- Previous similar projects and historical cost data such as previous tender submissions or a contract sum
analysis. - Other sources may include estimating price books such as Spons or Laxtons, the Building Cost
Information Service or specialist contractors.
What information do you need to be able to carry out an order of cost estimate?
- Building Location.
- The type of building.
- Floor area or number of functional units.
- Storey height.
- Whether raised access floors or deep suspended ceiling are envisaged.
- Initial floor plans, roof plans, elevations and sections.
- Requirements for refurbishment to existing buildings and enabling works.
- Indication of specification and quality.
- Indicative programme, procurement and contract strategy.
- Budget & cashflow constraints.
- Site conditions, probable ground conditions.
- Indicative M&E design intent, availability of utility services and the sustainability strategy.
- Details of professional fees, development costs, VAT and treatment of inflation
What is a cost plan?
- The cost plan presents the estimated cost of the development into an elemental or functional format.
- It shows how the design team proposes to distribute the funds available on the different elements of
the proposed building.
What is the purpose of a cost plan?
- It is used by the cost consultant to control the development of the design.
- It identifies the client’s agreed cost limit and how the money is to be allocated to the different elements
of the building.