Level 3 - Design Economics and Cost Planning Flashcards
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 key design principles that affect cost?
- Circulation space
- Size
- Shape
- Height
- Wall to floor ratio
- Grouping of buildings
- Specification
- Location
How does wall to floor ratio impact the cost of a building?
If the building has a lot of facade covering little area, the cost/m2 for the building would be high.
The cost for the high quantity + therefore cost of the facade is being divided over a small area.
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 circulation space affect the cost of a building?
The “cost”/m2 in relation to net area will be higher if the “cost” is carrying surplus non-lettable circulation space.
Too little circulation space however, will make a building unattractive to a tenant reducing the rent/sales value for the client
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’s a good, average and poor W:F ratio?
Good = 0.4
Average = 0.6
Poor = 0.8
What percentage of a construction cost would you expect for facades?
15% - 25%
What net to gross would you expect for an office?
Good - 80% - 83%
Excellent - 83% - 86%
Poor - over 87% or under 80%
What government guidance document discusses school areas?
Building Bulletin 103: Area guidelines for mainstream schools
What net to gross would you expect for a school?
70% - 75%
What is net vs non-net for schools?
Non-net = WCs, personal care, circulation, kitchen, plant, internal walls
Net = everything else, incl learning, storage, halls, staff space
What was the GIA for the school you worked on?
Phase 1 - 2024m2
Phase 2 - 7500m2
What was the net:gross?
72%
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
How is NRM2 structured?
1 - Context & definitions
2 - Rules for preparing Bill of Quants, Schedule of Rates, how to quantify non-measurable works such as risk, contractors design works
3 - Tabulated rules of measurement
Appendices
What’s the difference between a cost estimate and a cost plan?
Cost estimate gives a likely outturn of construction costs
Cost plan is an iterative process, updated and tracked as design progresses, to control the development of the design and ensure the client achieves value
What is a cost model?
Anything that models costs, e.g. cost plan, estimate, analysis
What’s benchmarking and how would you benchmark a project or element?
The process of collecting and comparing data within an organisation or external
to an organisation to identify the ‘best in class’
- Collect
- Compare
- Analyse
- Action
- Repeat
What’s the relationship between the RICS Property Measurement 2nd Edition, RICS Code of Measuring Practice 6th Edition and IPMS?
RICS Property Measurement 2nd Edition 2018 - This is a Professional Statement, states what we should use and when. Office and Residential = use IPMS.
Code of Measuring Practice 6th Edition 2015 = Guidance Note, how to measure GIA, NIA, GEA
IPMS - how to measure IMPS1, IMPS2, IMPS3 for offices, resi, industrial and now retail.
Why would you not use IPMS for say retail?
If the client wishes you to use something else, or if the project had been measured using COP6 prior to IPMS being released.
What is included/excluded in GIA?
Included:
- Core areas
- Area measured at ground
- Areas taken up by IW/columns/beams
- Stairwells, vertical projections
- Mezz floors w/ perm access
- Voids over stairwells
- Structural, raked or stepped floors are to be treated as a level floor measured horizontally
Excluded
- Perimeter wall
- Open sided external balconies
- Canopies
- Voids over/under raked/stepped floors
- Voids above GF atria
- Greenhouses, garden stores, fuel stores (resi)
What’s included/excluded in NIA?
Included
- Atria, lobbies etc that are tenant sole occupancy
- Kitchens in sole occupancy
- Built in cupboards etc in usable area
- Areas occupied by skirting/trunking
- Areas occupied by non-structural walls
subdividing accommodation in sole occupancy
Excluded
- Internal structural walls, walls enclosing
excluded areas, columns, piers, chimney
breasts, other projections, vertical ducts,
walls separating tenancies
- Common use areas (e.g. WCs, lobbies)
- Lift rooms, plant rooms, tank rooms
- The space occupied by permanent and
continuous air-conditioning, heating or
cooling apparatus, and ducting in so far as the space it occupies is rendered substantially unusable
- The space occupied by permanent,
intermittent air-conditioning, heating or
cooling apparatus protruding 0.25m or more into the usable area
- Areas with a headroom of less than 1.5m
- Areas rendered substantially unusable by
virtue of having a dimension between opposite faces of less than 0.25m
- Areas for vehicle parking
Define NIA
The usable area within a building measured to the internal face of the perimeter walls at each floor
level
Define GIA
The area of a building measured to the internal face of the perimeter walls at each floor level
Define GEA
The area of a building measured externally at each floor level.
What guidance does RICS provide on benchmarking and cost analyses?
RICS Practice Standards - Cost analysis and benchmarking, 1st edition 2011
What is a cost analysis?
An examination of the distribution
of cost across the construction elements of a project
What’s the difference between GIA and IPMS2 office?
- IPMS uses internal dominant face, GIA uses internal face (brick/block work or
plaster coat) - Rooftop terraces included but stated separately
What’s the difference between NIA and IPMS3 office?
- IPMS 3 measured to CL of walls separating two tenancies
- IPMS3 includes columns
What costs have you benchmarked?
Benchmarked cost/m2 office shell to Cat A, soft strip, academy
What is a standard shell to Cat A rate?
Circa £50-55sqft
What’s a residential unit cost?
£250/sqft