Design Economics

Question 1

What is a wall to floor ratio?

Answer 1

• This shows the relationship between wall area and floor area
• It is used to show the cost efficiency of the building
• The lower the ratio the cheaper the building as there is less external wall area per m2 of floor area

Question 2

What information would you expect the design team to provide at stage 3?

Answer 2

BIM Model
Plans
Design Specification
Planning conditions 
Structural Design
MEP Design 
Landscaping plan

Question 3

How would you prepare an estimate for M&E works?

Answer 3

• 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/functional unit rate

Question 4

Where are all economics of design defined?

Answer 4

The Code of Measuring Practice, 6th Edition, published by the RICS
NRM
BCIS

Question 5

What is construction to ‘shell and core’?

Answer 5

• The basic structure, services and envelope of the building

Question 6

What is a CAT A fit out?

Answer 6

Suspended ceiling tiles, raised floors, carpet, lighting, power distributed to floor plates

Question 7

What is a CAT B fit out?

Answer 7

Partitions, power distributed to floor boxes, data cabling, artwork and branding, upgrading CAT A finishes and toilet finishes etc

Question 8

How can efficiencies be increased?

Answer 8

• Optimising spatial efficiency by location of columns, plant rooms, lift shafts, riser ducts (put on the outside), frames, foundations, M&E, external walls (cladding), staircases, fire escapes, market factors, fit-out & specification

Question 9

Does your client want you to report the cost plan figures at tender date or at current price levels?

Answer 9

o Most clients who use construction cost estimates in their development appraisals want to use a current day construction cost, as they themselves are using current day rental rates or sale rates to calculate their revenue

Question 10

What are the non-physical elements of a cost plan?

Answer 10

o	Main contractors’ preliminaries.
o	Contractors’ overheads and profit.
o	Project/design team fees.
o	Other development/project costs, eg insurance, planning fees, decanting and Section 106 agreement contributions.
o	Risk allowances.
o	Inflation.
o	Value Added Tax.
o	Other considerations e.g. Capital Allowances, Land remediation allowances and Grants.

Question 11

What was the NIA : GIA on one of your projects?

Answer 11

78% on Tolworth Phase 1

Question 12

What was the Wall : Floor on one of your projects?

Answer 12

0.67 - not particularly efficient, due to the size of external wall and large car park area

Question 13

What was the storey heights on one of your projects?

Answer 13

2. 7m floor to ceiling

3. 1m slab to slab

Question 14

How did you challenge the design team on Phase 2 to improve the efficiencies?

Answer 14

Reducing core areas
Reduction of GIA but keeping the same NIA, smaller building
Design Efficient targets

Question 15

Does reducing communal areas not have a negative effect on the building itself?

Answer 15

It will affect the attractiveness of the building if there are small communal areas, however, the architect confirmed that the communal areas were significantly larger than the min requirements

Question 16

How does wall:floor impact cost?

Answer 16

The higher the wall area, typically there may be greater costs as it could mean a higher building, effecting the structure

Also, poor design efficiency leads to lesser returns for the client

Question 17

On Tolworth what was the NIA : GIA?

Answer 17

Over a number of buildings these were reaching 60% but it ranged from 60% to 75%

Question 18

How did you advise the client that the Net : Gross was poor?

Answer 18

By reading the British Land it sets out minimum stds
Benchmarking
Ratio analysis against other projects to understand where Phase 2 buildings sat in comparison with other developments

Question 19

What is ratio analysis?

Answer 19

Looking at the key design efficiencies on a “dashboard” to show comparisons and benchmarking of these against other similar projects

Question 20

How did your advise on design economics influence the design?

Answer 20

The design team would have tried as best as possible to reach the targetted NIA:GIA that I set out in the early stage estimates, therefore design reflective of this.

It may mean costs increase, but there will be a greater area of net sellable area for the client to drive returns

Question 21

What was the cost impact with increasing the NIA:GIA on the later phases on Tolworth?

Answer 21

£13m but circa 20% across 8 buildings increase on Net Areas on the projects which would have lead to greater returns on investment for my client