Design Economics Flashcards
What is the difference between a cost plan and Order of Cost Estimate?
An estimate is a forecast of construction cost. The purpose of an order of cost estimate is to establish affordability of a proposed development for a client.
A cost plan broken down construction costs into the elements to understand the cost limit of each element of the building. Provides a frame of reference to develop the the design and maintain cost control.
What design detail would you expect in RIBA Stage 0 (Strategic definition and brief)?
Stage 0 is about determining the best means of achieving the client’s requirements.
An open mind is required because a building might not be the most appropriate solution.
Stage 0 is not about design or the practical details. It focuses on making the right strategic decisions and capturing them in a Business Case. The stage involves considering the pros and cons, Project Risks and Project Budget for a range of options and, where necessary, carrying out Site Surveys and corresponding planning appraisals, before undertaking a comparative analysis and recommending and ratifying the best option for delivering the Client Requirements.’
What design detail would you expect in RIBA Stage 1 (Preparation and brief)?
Stage 1 is about developing the detail of the brief and making sure that everything needed for the design process is in place before Stage 2. This includes ensuring that the brief can be accommodated on the site. Involves:
Developing an initial project brief. This may include; considering feedback from previous projects, defining overall spatial requirements, carrying out surveys and quantifying the budget.
Carrying out feasibility studies.
Undertaking a project risk assessment, including; planning risks, programme and procurement strategy.
Assembling the project team and defining their roles and responsibilities.
What design detail would you expect in RIBA Stage 2 (concept design)?
Stage 2 is about getting the design concept right and making sure that the look and feel of the building is proceeding in line with the client’s vision, brief and budget. Includes:
- The design concept.
- Outline specifications.
- Schedules of accommodation.
- A planning strategy.
- The cost plan.
- Procurement options.
- Programme and phasing strategy.
- Buildability and construction logistics.
What design detail would you expect in RIBA Stage 3 (spatial coordination)?
The purpose of Stage 3 is to spatially coordinate the design before the focus turns to preparing the detailed information required for manufacturing and constructing the building. Includes:
- Schedules of accommodation, including occupancy numbers for each space.
- Key assemblies, component drawings and schedules
- Structural plans sections, elevations and specifications:
- Building services plans, sections and elevations
- Fire strategy,
What design detail would you expect in RIBA Stage 4 (technical design)?
Stage 4 is about developing the information required to manufacture and construct the building. This requires information from the design team and the specialist subcontractors employed by the contractor, regardless of which procurement route is used. Includes:
By the end of the stage the architectural, structural and mechanical services design and specifications should describe all the main components of the building and how they fit together, any performance specified work should be defined and there should be sufficient information for applications for statutory approval to be completed. Room data sheets are also likely to have been prepared along with outline technical specifications.
What design detail would you expect in RIBA Stage 5 (construction)? now known as Manufacturing and construction.
Stage 5 is when the building is manufactured and constructed.
What design detail would you expect in RIBA Stage 6(handover and close out)?
By Stage 6 the building will be in use and the emphasis of the project team will have switched to closing out any defects and completing the tasks required to conclude the Building Contract.
What design detail would you expect in RIBA Stage 7 (in use)?
This is the period when the building is in use, lasting until the building reaches the end of its life.
What can you do to adjust costs for time and location?
Indices can be used which set a base for project data. Indices that can be used are cost and time.
How did you ensure NRM compliance with external walls?
This was measured on the external wall at the centre line using m2. The measure needed to be different where there were columns and beams as the wall build up differs here.
How did you ensure NRM compliance with internal walls?
This is measured on the centre line of the internal wall or partition. No deduction is made for door openings, screens or the like. The internal skin of external wall is included within external wall.
How did you ensure NRM compliance with external works?
This mainly consisted on hard and soft landscaping which was on a m2 basis, however also included counts for outdoor furniture, linear metres for external drainage and numbers for tree planting.
What section of NRM is external works?
8
What are the NRM subheadings for external works?
- 1 Site preparation works
- 2 Roads, paths, pavings and surfacing
- 3 Soft landscaping, planting and irrigation
- 4 Fencing, railings and walls
- 5 External fixtures
- 6 External drainage
- 7 External services
- 8 Minor building works and ancillary buildings
How do you know that quantities from BIM are correct?
When checking my quantities, I always cross check with drawings, for example, the perimeter by height for external wall areas.
How much do precast concrete panels cost per m2?
Market tested rates for the precast RC panel range between £500 and £600/m2.
Insulation was between £20 and £40 for each layer.
The metal stud range between £25 and £50.
Plasterboard was at £10/m2 each layer.
What were the cost implications for installing windows on precast concrete panels?
Installing windows on precast concrete panels cost an additional £50 per window for the increased risk, time and labour and this was factored in my external wall rate.
What were the cost implications for special design features and what were they?
This included articulations proposed by the architect and the costs for these was for extra time and risk detailing the precast panels. The extra rate was between £50-£150/m2 extra.
What effect did the precast concrete panels have on the main contractor preliminaries?
Using precast concrete panels meant that there would be less time on site as it is quicker construction than other methods such as traditional brick. This would reduce the preliminary running costs
What elemental costs changed in your Pines Way order of cost estimates between stage 0 and 2?
- Facade reduced after design development meant there was less blocks which were bigger
- Cost increase for internal wall and partitions as OCE was based on a full measure and not benchmark
- Substructure increase as based on actual measure and not £100/m2 gia
What were the efficiency changes in your table of efficiencies for Pines way?
The W:F ratio reduced from 0.7 to 0.55.
What were the laborers hourly rates in the Bath area compared to elsewhere?
In Bath these rates were circa £25/ hour compared to £30/hour in London.
Why are costs different in different locations?
- Wages
- Site logistics
- Proximity to services and supplies
- Availability of labour
How is the NRM set out?
NRM1 comprises four parts:
- Part 1 sets out the context and definitions.
- Part 2 explains how to prepare an order of cost estimate.
- Part 3 explains how to prepare an elemental cost plan.
- Part 4 provides tabulated rules of measurement for the preparation of cost plans.
What were the key exclusions in your OCE?
VAT Inflation Legal costs Planning costs Unexpected ground conditions Land acquisition costs
How did you build up your preliminaries costs?
This can be done using the NRM preliminaries book.
What is an alternative to applying inflation within the OCE?
Fluctuation clauses can also be applied. This includes option A, B and C.Changes in taxation.
Changes in the cost of labour, transport and materials (sometimes referred to as ‘escalation’).
Increases in head office or administrative costs.
