Design Economics & Cost Planning Flashcards
Can you tell me some of key factors which impact the cost of a building?
Location Size Shape Height Specification Grouping of buildings
How does size impact the cost of a building?
A bigger building will have economies of scale, reducing the price subject to the size being designed efficiently
How does the height of a building affect the cost?
A tall building may require more lift cores, reducing net space on each floor plate.
Bigger foundations, beams etc required
Requirements for better facades to deal with greater wind loads and sprinkler requirements for buildings over 30m high (approved doc B)
How does the shape of a building affect the cost?
Curved shapes are expensive to manufacture + construct due to complexity
Inefficient shape could cause high wall to floor ratio
Most efficient shape is a square (excl circle because of curve)
How does the grouping of buildings affect the cost?
Less facade per m2
Ability to share plant etc
What might be risks associated with using BCIS?
Can’t interrogate rates as they are secondary
Sometimes BCIS publish data that is ‘provisional’ and not finalised yet
What might be a problem with market testing?
Suppliers may provide lower costs to ‘get in the door’ or win jobs
What are some of the key design metrics?
Wall to Floor Floorplates Net to Gross Floor to Ceiling Heights Shape of the building
What is BCIS used for?
You can use BCIS for a source of cost data.
Data can also be manipulated or adjusted to reflect location or dates.
What are the RIBA work stages
0 – Strategic Definition 1 – Preparation & Briefing 2 – Concept Design 3 – Spatial Coordination 4 – Technical Design 5 – Manufacturing and Construction 6 – Handover 7 – Use
What are the full names for NRM1 and NRM2?
New Rules of Measurement 1: Order of cost estimating and cost planning for capital building works
New Rules of Measurement 2: Detailed measurement for building works
How is NRM1 structured?
1 - Context & definitions
2 - Rules for preparing OCE, how to quantify non-measurable works
3 - Rules for cost planning, how to quantify non-measurable works
4 - Tabulated rules of measurement
Appendices
What is an order of cost estimate?
- The determination of possible cost of a building(s) early in design stage in relation to the employer’s fundamental requirements.
- Prior to preparation of a full set of working drawings
What is an elemental cost plan?
- the critical breakdown of the cost limit for the building(s) into cost targets for each element of the building(s)
What are the 3 main ways to measure building works in a cost estimate?
Floor Area Method
Functional Unit Method
Elemental Method
What information would you expect from the Client before preparing an Order of Cost Estimate?
Location and availability of site. Statement of building use and size. Any refurbishment requirements. Initial project/design brief. Draft programme. Site conditions. Budget/cash flow constraints. Construction procurement options. Life span of the proposed building.
What information would you expect from the Architect before preparing an Order of Cost Estimate?
Design study sketches or drawings.
Schedules of areas.
Legislative constraints.
Initial risk register.
What estimates and costs plans are listed in NRM1?
- Order of Cost Estimate
- Formal Cost Plan 1
- Formal Cost Plan 2
- Pre-Tender Estimate
- Bills of Quantities
- Post Tender Estimates
What are the key elements of on order of cost estimate?
Facilitating Works Building Works Contractor Prelims Contractor OHP Construction Cost Fees Other development / project costs Risk Allowance Inflation
How is a Cost Plan structured?
- Executive Summary
- Cost Summary
- Schedule of Areas
- Unit Mix
- Pricing Notes, Assumptions and Exclusions
- Cost Reconciliation
- Benchmarking
- Detailed Cost Build Up
- Basis of the Cost Estimate
Which would you expect to have a lower wall to floor ratio and why between an office building and a residential building?
You would expect an office building to have a lower wall to floor ratio as they generally have less articulation within the external wall compared to residential buildings.
What is Value Engineering?
The systematic approach to enhance value by eliminating unnecessary cost while maintaining function.
What RIBA Stages would you do a cost estimate at?
Typically, you would have a cost estimate in the early stages of the project. This would be at Stage 0-
2 where there are less drawings and information.
What RIBA Stages would you do a cost plan at?
I would do a cost plan at RIBA Stage 3 and RIBA Stage 4.
