‘This is a wonderful book that should be on the desk of every architect and planner. It shows how

Ensure the rights can be measured and verified
We do not know how to measure biodiver-
sity. For example:
• 
Salinity has complex contributing factors 
and non-point sources
• 
There is global agreement on measuring
tons of CO
2
equivalent, but not science 
on how much carbon soil and vegetation
sequesters 
• 
Biodiversity varies between ecosystems
The measurement of increased biodiversity 
is through the ‘surrogate’ of space allocated 
for:
• 
Natural ecosystems (eg roof gardens)
• 
Eco-services (eg vertical wetlands) 
We do not need to know equivalence 
of CO
2
sequestered, as design for eco-
services would serve multiple values (eg 
air and water cleaning and environmental 
amenity)

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328
Positive Development
Offsets Credits
Ensure the proper use of the rights can be enforced
Non-point sources of negative impacts are 
hard to monitor. For example:
• 
In emissions trading schemes, smoke 
stack detectors could be linked to
monitors at the regulatory agency
• 
In eco-service issues, it is difficult to 
measure negative impacts or their non- 
point sources
Enforcement of ownership of eco-service 
credits is no special problem, as it runs 
with the property:
• 
Post-occupancy evaluation is a
well-established method for large 
buildings
• 
If the infrastructure for eco-services
has been put in place, there is no
reason not to use it for landscaping
values
Ensure there are enough parties to cover transaction costs
There are lots of fossil fuel industries that 
emit carbon and need credits, but: 
• 
There are not many who want to trade 
in biodiversity 
• 
Eco-service trading therefore needs to 
be subsidized
All urban property owners could take
advantage of a DES scheme in retrofitting:
• 
Properties sell often, which would
enable businesses to ‘churn’ retrofit 
projects
• 
Costs can be covered by performance 
contracts