Blue Green Solutions

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Blue Green Solutions Guide

5. Case Studies

The  case studies demonstrate how the BG Systems approach can substantially enhance the 

sustainability, resilience and cost-effectiveness of BG Solutions in both new and existing urban 

developments.

1. Zagreb University Campus

     Page 28

Demonstrates the multiple benefits of 

the BG Systems approach, via the Goal 

Driven Planning Matrix (GDPM), at the 

district/master planning level.

2. London Decoy Brook

      Page 30

Illustrates how monetising the wider 

benefits of BG solutions facilitates their 

use for managing environmental risks to 

urban infrastructure.

4. Marlowe Road London

      Page 34

Demonstrates the application of the BG 

Systems approach to the planning of a 

residential area.

5. Šabac city Masterplan

      Page 36

Describes how the BG systems 

approach has been utilised to develop a 

regeneration plan for an entire city.

6. Imperial College London

      Page 39

Demonstrates how to monitor and 

model the operational performance of 

BG solutions at the level of an individual 

building.

3. Budapest City Park

      Page 32 

How to achieve a closed loop (urban 

metabolic) system for water, energy and 

waste using the BG system approach.

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Blue Green Solutions Guide

Case study 1: Zagreb University Campus 

Deployment of the BG Systems approach to deliver an enhanced master 

plan.

Background

BG Systems Approach 

Main Outcomes 

In 2011, the University of Zagreb held a 

competition for the design of a flagship campus 

on a former military airfield located inside a 

forest. Sustainability, environmental quality and 

resource efficiency were the key judging criteria. 

Njiric Architects and EnPlus won this competition 

and were commissioned to create a Master Plan.

A full-scale analysis was conducted using the 

BG Interaction Matrix (see page 27). The analysis 

identified a number of potential interaction 

synergies that could provide significant life-cycle 

cost savings for the campus. The integration of 

groundwater resources, underground storage of 

energy and specially planned vegetation proved 

to have significant potential. In particular, by 

integrating the campus with the forest, with 

the addition of selected tree species planted 

in optimally configured positions, the natural 

functions of the forest could be harnessed to the 

benefit of the campus. 

Trees with large leaf surface areas were 

positioned to align with summer winds, hence 

maximising evaporative cooling of the buildings. 

The southern façades of the buildings were 

protected from summer solar radiation using 

trees that lose their leaves early in October, thus 

also enabling solar passive heating in the winter. 

Evergreen trees were positioned perpendicular to 

predominant winter winds to reduce heat losses 

in the winter. 

The optimisation of the master plan via the BG 

Systems approach yielded a near-zero-energy 

campus, with overall energy savings of 68 per 

cent for heating, 92 per cent for cooling and 60 

per cent for electricity. 

Due to the strategic positioning of the trees, 

indoor summer temperatures were 4oC lower 

and indoor winter temperatures were 6oC 

higher, relative to a zero-tree (i.e., absence of 

trees) scenario. The energy consumption of the 

buildings was 26 per cent lower.

Life-cycle Cost Analysis found that the payback 

time for the additional investment required, 

compared to standard construction costs, was 

approximately 4.8 years.

Figure 18 demonstrates the campus’s integrated 

approach to local reuse of water, localised energy 

production and recovery for the campus, and use 

of greenery for passive building design.

The energy for the campus was harvested from 

nature by means of using solar energy for passive 

heating, hot water production and electricity 

production by PV panels. Underground energy 

storage (in deep rock), as well as ground water, 

are combined with the solar energy harvesting 

system to create a unique, natural energy 

production plant for the campus. The result is a 

near-zero energy, university campus.

Energy flow diagram and related annual energy savings for Zagreb University campus.

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Multi-purpose water use and reuse and its interaction with localised energy production and 

recovery, and vegetation.

Energy recovery

Energy storage

Grey 

water

Black 

water

Decentralized 

WW treatment

Wind driven ventialtion 

with heat recovery

Waste water quality 

improvement

Heat island 

mitigation

Electricity 

and water 

exchange

Ground water aquifer

Mains

Artificial

Natural

Building energy 

and water storage

68%

60%

92%

Heating

Cooling

Electricity

P

a

yb

ack 

Pe

riod: ap

pr

o

x

i

m

a

te

ly 

5

 

ye

ar

s

A

n

n

u

a

l 

E

nergy

 

Sa

vings

Passive

Heating

2000MWh/y

Sun Collectors

3400MWh/y

Photovoltaic

5000MWh/y

Seasonal 

Ground

Energy Storage

2000MWh/y

Ground Water

3500MWh/y

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