Sustainable Building Challenge of WSB 2014

Sustainable Building Challenge of WSB 2014
Session 144 - 2nd oral session
Do our buildings perform as intended? - 2nd oral session
Chairman: Rietz, A.; Federal Institute for Research on Building, Urban Affairs and Spatial
Development (BBSR), Berlin, Germany
Speakers:
Müller, J.1, Schablitzki, G.2, Löhnert, G.3, Kerz, N.1, Ammon, S. 4, Possemiers, T. 5,
Atkins, R.6, Larsson, N. 7
1
Federal Institute for Research on Building, Urban Affairs and Spatial Development (BBSR),
Berlin, Germany, [email protected] / [email protected]
2
Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety
(BMUB), Berlin, Germany, [email protected]
3
sol·id·ar planungswerkstatt, Berlin, Germany, [email protected]
4
Institute for Federal Real Estate (BImA), Berlin, Germany,
[email protected]
5
CENERGIE, Berchem, Belgium, [email protected]
6
Richard Atkins Architecture, Tranent, United Kingdom, [email protected]
7
International Initiative for a Sustainable Built Environment (iiSBE), Ottawa, Canada,
[email protected]
Abstract: The SB Challenge is placed as a key feature at the World Sustainable Building
Conference in October 2014 Barcelona. The main target was to discuss the comparison
between the actual performance in use and the performance that was predicted at the design
stage. Selected Buildings representing a high standard of sustainability from Belgium,
Germany, the United Kingdom as well as Japan, Mexico and Singapore have been analysed.
The selected buildings show a wide range of construction tasks with respect to clients, users
and architectural solutions. The sustainable performance played a major role in the design
phase of all the buildings. The intensive sustainability consulting usually led to a high
standard of sustainability at the time of completion of the buildings. Thus, several buildings
already achieved the highest level in the sustainability assessment. To ensure that this
standard will be realized during the using phase of the buildings, different monitoring systems
were checking whether the set objectives could really be achieved during the first years of
operation. For that purpose different measuring systems have been applied. The instruction of
the users on the technical services of the buildings provides an important part in the
commissioning phase.
For the selected buildings the results of the first years after commissioning are available.
In some cases the measurements of monitoring during the first and second year do not indicate the expected results. The differences between the design stage and the actual operational
performance can be caused by very different reasons. There may be changes in building use
or occupancy profile. However, technical issues are frequently relevant. A comprehensive
measurement of the actual building data is important. Only on this basis, the readjustment of
the technical equipment is feasible. And after these activities, the results usually confirm or
even go below the predicted values.
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Keywords: Assessment, Monitoring, Use and Operation,
Introduction
The main target of SB Challenge 2014 is to discuss about the comparison between the actual
performance in use and the performance predicted at the design stage. Selected buildings with
a high sustainability standard from Belgium, Germany, the United Kingdom as well as Japan,
Mexico and Singapore have been analysed. The difference between predicted and actual
performance can provide us with an understanding of how fast we are moving towards
sustainability.
The International Initiative for a Sustainable Built Environment (iiSBE) determined the exact
format for presentation in consultation with the organizers of SB14. They developed Key
Performance Indicators (KPI) to provide objective comparison of building performance in the
operation phase and the requirements addressed during planning phase. The key research
question is whether buildings have lived up to their potential, and this approach is fully
compatible with the overall theme of WSB14 “Are We Moving As Quickly As We Should?”
The performance parameters included in the core set of KPIs developed by the SB Challenge
team cover predicted and actual performance data in the following areas:

Site

Energy and Emissions
(e.g. Building energy use intensity for all operating end uses, On-site renewable electricity generated or Greenhouse gas from delivered energy for all operating end uses)

Material and Waste

Water
(e.g. Gross water use per occupant / per m² per year or
Net potable water per year supplied to the project)

Indoor environmental quality
(e.g. Daylight factor, Temperature range or
CO2 concentration level in a typical occupancy)

Economic factors
(e.g Construction cost, Operating energy and water cost)

Occupancy factors
(e.g. typical numbers of occupants per day or
typically weekly operating hours of the building)
In the session, the results of the selected projects will be presented. A special attention is paid
to the commissioning of the building and the monitoring in the operating phase. Sustainability
assessments arranged during occupancy phase enable specified records, influence and control
the performance qualities of processes and the building itself. The result of the SB Challenge
will be presented in a poster exhibition during the conference in Barcelona and documented
on the internet accordingly.
2
Federal Ministry for the Environment, Nature Conservation, Building and
Nuclear Safety, Berlin, Germany
The particular challenge of the new location for the Environment and Building Ministry was
to realize ecological exemplary concepts in a historical urban context. As a result the Ministry
is the first Federal Ministry to work in a low energy and passive house, which already become
a model project for modern i.e. ecologically sustainable and innovative construction.
Figure 1: The overall ensemble
Figure 2: Berlin Wall integrated into the new building
The new home of the Ministry is the former Prussian Ministry of Agriculture from 1916 in
Stresemannstraße in Berlin. An extension was added, which retains parts of the Berlin Wall.
The building finished in 2011 connects two turns of the century: the architecture of the period
around 1900 with modern architecture of present days in the early 21st century. The historic
appearance of the old building has been restored by the sloping roof and the dormer windows
and the historical building regains its inner structure. However the new building consistently
presents itself as an autonomous structure in today´s architectural language. So the rows of
narrow, rectangular windows do not abide by a fixed rhythm. Openness is another elementary
characteristic of the Ministry building: Despite all the security requirements, the building is
never closed in character, both by an open loggia, the open inner courtyard and the ground
floor zone that turns towards the city and integrates the ministry into urban life.
The Ministry is the first federal authority to work in a low energy and passive house
respectively. This concept for a representative new office building in Berlin´s very centre is
unique to date. Solar heat gain for passive buildings is not easily implemented in a narrow
metropolitan location. Due to shading caused by neighboring buildings more attention had to
be paid to other issues: a high insulation level, air tightness and highly efficient heat recovery.
Great efforts have also been made to minimise the power requirements for electric lighting,
ventilation and office equipment.
The power and heat supply for the new ministry building takes innovative paths to pursue a
sustainable energy management by using a whole range of modern technologies.
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Fuel cells and photovoltaics, district heating and cooling from heat-power-cooling-cogeneration, geothermal and wastewater heat recovery are all elements of the planned concept. Some
of the different energy technologies are deliberately installed for demonstration purpose.
A significant contribution to saving energy was made by reducing the exterior shell of the
building: The old building´s inner courtyard was covered and converted into an atrium with
glazed roofing. Usually, this space acts as an effective climatic buffer zone. Only in case of
demand the atrium is heated by floor heating.
Figure 3:
The northern courtyard,
© Ursula Böhmer, Berlin
Figure 4: Ground Floor
© Geier Maass Pleuser Architekten, Berlin
The planning process was intensively accompanied by experts in the fields of sustainability
and energy. All the targets were defined in a so-called specification sheet (Pflichtenheft).
The entire annual primary energy demand for heating, hot water, ventilation and all electric
devices together may not exceed 120 kilowatt hours per square metre in a passive house. The
Ministry itself has set the target of only 100 kilowatt hours for the building. To ensure, that
these and other intended values are not merely set down on paper, a monitoring system will
check if these values will really be achieved in the first years of operation. Therefore a
comprehensive measuring system was built in. Temperature, humidity, volume flow rates and
electricity consumption are measured at 350 positions in the building. The monitoring of
energy-optimised buildings itself requires a fine-tuning phase in order to optimise the interaction of services. The data of 2012 and 2013 analysed within SB Challenge 2014 derive from
this fine-tuning-phase. The proper evaluation of the consumption for the monitoring is
possible since 2013 and will be finished in 2015. Only with the differentiated consumption
analysis it will be possible to make a statement about the deviance and as a result to take
corresponding measures to optimise the operation process.
With the official residence of the minister for environment the German government
accomplished a role model in terms of energy, resources and building materials.
Moreover any positive effects on climate, health protection or protection of resources,
can not be converted directly into Euros, but the efforts will definitely be worthwhile.
4
Main Customs Office, Hamburg, Germany
The new building of the main customs office Hamburg is located in the urban development
area HafenCity. Features of the building are the high energetic quality of the building
envelope, a good eco-balance and low construction and lifecycle cost. This was enabled by an
effective and integrated cooperation of all actors from the very beginning of the project.
Figure 1: View in south-west direction
Figure 2: Ground Floor, © Winking Froh Architects
The design of the new building integrates in the surrounding of the existing listed warehouse
buildings of the 1950s. The compact 7-story, L-shaped building closes the block east of the
Magdeburg harbor. The main entrance of the building is located at Koreastraße. The post
customs office in the ground floor got a separate entry via the lobby and can be operated
independently. The counter area - the core of the building - is located in the first floor and
extends over the upper storeys supplied by natural lighting from a skylight. The offices are
aligned around the hall along the building.
Based on the trapezoidal shape of the site and the orthogonal shape of the ground plan, the
facades are structured with ribbon windows of four different types of box-type windows:
parallel and flush in the yard area, parallel and plastic at the gable walls of Shanghaiallee and
Hongkongstraße and wedge-shaped and sculptural along Koreastraße. By alternating of the
gable surfaces and the ribbon windows between the 4th and 5th floor, a powerful structure has
been developed, which responds to the proportions of the surrounding warehouse buildings.
For the facades dark-red bricks have been used. Green glazed bricks emphasize the warehouse
character adopting the color of the customs and interpreting the historical brick décor of the
warehouse district in a modern contemporary texture.
An integrative energy concept has been developed already in the early design phase to
achieve the ambitious goals concerning the power and heat supply and to stay below the legal
minimum requirements (German Energy Saving Ordinance, EnEV).
The building is supplied by district heating, which has positive impacts on the overall balance.
A significant contribution to energy saving is achieved by natural ventilation of the offices.
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This is made possible by the exterior solar shading device, protected against wind by an outer
glass panel and the concrete ceilings serving as thermal storage. Only a couple of rooms have
a ventilation system with heat recovery. The office lighting is equipped with presence
detectors and daylight controller. To compensate that the complete site was overbuilt the roof
is built as an extensive green roof. It is prepared to be used for a future installation of
photovoltaic panels.
Figure 3: Core atrium, © C. Gebler Fotodesign Gebler
Figure 4: Detail of the façade
As one of the first administration buildings the new building of the main customs office was
awarded the silver certificate of the German Assessment System Sustainable Building for
Federal Buildings (BNB) in 2012. The building achieved outstanding results particularly for
the ecological and the economic qualities. According to the energy performance certificate of
the main customs office the primary energy demand of the building undercuts the set value of
the German Energy Saving Ordinance (EnEV 2007) by 68 %. In addition the usage of natural
and durable materials contributes to the sustainability of the building in itself. The project was
assessed after completion (post-assessment), therefore the result is even more appreciable.
Comparing calculated and actual performance of main customs office Hamburg, it should be
taken into account, that the estimation of the values at design stage was made more roughly in
comparison to the other German projects, what leads to large deviations.
During the first year intensive user education about the technologies of the building has been
carried out . For each floor one person has been chosen on a voluntary base who will
exemplarily assist their colleagues in case of demand.
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Paul-Wunderlich-Haus, Eberswalde, Germany
The Paul-Wunderlich-Haus repeals the traditional idea of administrative buildings. Instead of
long, gloomy and deserted corridors, this building is a transparent, future-oriented workspace
located in the very city center of Eberswalde. The design is the result of a Europe-wide
architectural competition by GAP Architects, Berlin and has been funded by the German
research initiative Energy Optimized Building, EnOB.
Figure 1: View from the center of the complex facing North, © Martin Duckek
The program for administration of the district of Barnim, situated next to Berlin is divided
into four buildings which respectively accomodate different departments such as the head
office. Every building has its own identity and its own infrastructure to insure that, in case of
demand, each of the building can be used separately from the remaining use. The ground floor
mostly accommodates spaces for public access such as retail and a small café. The head office
provides an exhibition of the artist Paul Wunderlich and is open to the public every day.
The upper floors are occupied by the district administration. The design represents the new
image of service-orientation. Flexible spaces are designed under the consideration of
optimised use of daylight and good acoustic damping. Consequent application of ecological
building materials and an efficient ventilation system ensure high indoor air quality.
The heating system uses the soil as a heat source in winter via the foundation piles equipped
by water driven tubular heat exchangers. Heat pumps generate the low temperature level as
required. In summer the soil can be used directly as a heat sink; the peak load is covered by a
reversible heat pump. PV panels (640 m², 80 kWp) are mounted on the roof of the multistorey car park adjacent to the so called „Kopfbau“. In addition, an extension of the PV
system of approx. 40 kWp is installed on the south façade. This system has been realised by a
contracting solution.
Coolers on the roofs allow an active regeneration of the pile heat exchanger system in the
ground and thus for a favorable overall system performance. In summer most of the time the
system is operating in free cooling mode without supporting reversible heat pumps.
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The exterior solar shading consists of bipartite Venetian blinds providing daylight access via
the top area deeply into the space. The position of the blinds in the lower area will be
optimised according to daylighting requirements. The shading devices are controlled façadewise and floor-wise as a function of solar irradiation and indoor air temperature. In addition,
an interior glare control can be positioned manually according to individual users demand.
Figure 2: Ground Floor, © GAP
Figure 3: Conference Room,© Martin Duckek
Electric lighting for the workplaces is provided by floor lamps developed individually for this
project. These lamps have a relation between indirect and direct magnitude dependent on the
space depth (indirect proportion rises with increasing room depth). To optimise public
services the administration is organized in different ways and in different spatial patterns.
The modular design of façade and technical equipment allow different variations of offices,
cellular offices, combination offices and offices for larger groups or even landscape structure.
The project has been monitored in detail within the German Funding Initiative Energy
optimised Building, EnOB of the Federal Ministry for Economic Affairs and Energy. By this
way a more accurate documentation of design data could be provided according to KPI.
The building was assessed as part of the pilot phase for the assessment system DGNB/BNB
module Office & Administration Buildings. It reached a still unachieved level of 89.5%
fulfilment that equals a grade of 1.18. In 2013 the building was assessed with the DGNB
module Existing Building. The assessment was certified in Gold and 90.9 % fulfilment.
Moreover, the building participated very successfully in a pilot application for testing the
German BNB module Use & Operation. As the former Facility Manager of the building
stated: “Though it took almost two years for fine-tuning, the expectations of energy and
comfort performances could be satisfied. In general, the building has become the central point
in the city. In my point of view, the administration, commercial and event venue is a great
success and a significant improvement”.
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Aéropolis II, Brussels, Belgium
The passive office building Aéropolis II, located in Brussels, Belgium, was built between
2008 and 2010. The design of the project started in 2005, what allows it to be considered as a
pioneer in the development of energy efficient and passive office buildings in Belgium.
Thanks to the integrated design, efficient strategies could be developed while limiting
additional costs compared to similar buildings.
Figure 1: External facades © Architectes Associés
Figure 2: Floor plan © Architectes Associés
The design team was made of architects, engineers in techniques and energy advisers. They
collaborated from the early beginning of the project to design the 10,100 m² big passive office
building, made of 6 levels of office spaces (7,400 m²) and 2 levels of parking (2,700 m²).
The compact building is designed with a patio in its centre, allowing daylight to enter every
workspace. From the early beginning, a great flexibility was asked in the space organization.
To meet this demand, every potentiel room is equipped with incoming fresh air and extraction
of outgoing air, quality daylighting and artificial lighting, a window that can be opened for the
night cooling as well as control elements (light sensors, presence detectors, …). This allows a
further partition of the space without any substantial change in the techniques.
Aéropolis II lowers its energy consumption for heating and cooling by applying the passive
standards and strategies that enable a passive cooling of the building during the summer.
The strategy follows the Trias Energetica: heating and cooling demands are reduced at the
basis and the low remaining demands are covered by using low tech installations. Low
heating demands are achieved by designing a compact building with high insulated walls and
a high level of air tightness (n50 = 0.6 h-1), combined with heat recovery on the ventilation
system and an earth heat exchanger. Solar gains are also optimized through the windows.
The building is heated via ventilation only, associated to a 160 kW gas boiler that supplies the
heating batteries with hot water.
The cooling demands are reduced by the control of the solar loads during the summer, thanks
to external automatized solar shades and by the high performing lighting system, with a
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control system based on presence and available daylight. Thanks to its low cooling demands,
the building can be cooled down using passive strategies only: the earth heat exchanger
lowers the temperature of incoming fresh air, while intensive night ventilation (night cooling,
5 ACR/h) ensures the thermal mass of the construction to be cooled down during the night
and to give its freshness back progressively to the ambiance during the day.
Figure 3: Energy concept of Aeropolis II © Architectes Associés
Since 2010, the performances of the building in terms of energy consumptions and comfort
are followed. The actual heating consumptions reached 20 kWh/m²a over the last years. This
result, above initial expectations, can be explained by two factors: the low occupancy level of
the building and the fine tuning of installations which took place during the first two years to
optimize their working and performances.
Comfort is also measured in the building: during the first months of occupancy, the working
of the night cooling has been closely followed with in situ measurements (temperature
sensors). In the beginning, those measures showed problems with the night cooling, due to
errors in the way the system was programmed. Step by step, the working of the system has
been optimized and finally, comfort temperatures have been reached in the whole building.
The work in design team since the beginning of the project allowed a strong design of the
building, including architectural aspects as well as techniques and a reflection on the future
occupancy and use of the building. The strategies developed to reach the passive standards led
to low energy consumptions of the building, as well as the acheiving of a high inner comfort
(temperature, lighting, indoor air quality,…), experimented day after day by the building user.
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Norton Park, Edinburgh
Built in 1902, by the early 1990's Norton Park was no longer in educational use. In 1995 it
was listed at Grade B in recognition of its architectural quality. In 1999 an award winning
refurbishment was completed which cut energy costs and CO2 emissions by two-thirds to
levels still not required by Scottish regulations for new buildings today. The additional costs
associated with achieving this performance were paid back in the first ten years of occupation.
Figure 1: Main Elevation © Burnett Pollock Ass
Figure 2: Galleries © Burnett Pollock Ass
The project was monitored on completion and has been recognised by a number of awards1,
academic papers (Atkins, 1999) (Atkins, Emmanuel, 2012) and cited as a case study
(BRESCU, 2001) (CIBSE, 2002) (The Prince’s Regeneration Trust, 2010). Around 20% of all
buildings in Scotland predate 1919 and Norton Park is typical of the thick stone walled and
slated roof construction of the Victorian era and emblematic of the first wave of type planned
schools. Though structurally solid the building and its services had been neglected as its use
had declined. The 1999 refurbishment consisted of a thorough repair of the external fabric to
the highest conservation standards, the introduction of high levels of insulation, the
restructuring of the internal floor layouts and the addition galleries within the large ground
and first floor rooms to maximise usable space and completely new internal services.
The building is now co-location offices for 25+ charities and voluntary organisations who
benefit from lower occupancy costs in part due to the lower energy and water costs. One
charity reported soon after occupation that the quality of space was such that their absentee
rate had dropped by 40%. The external walls and roof were insulated and highly efficient
double glazed inner windows were installed reducing the average U-value of the building
fabric from 1.94 W/m2K to 0.3 W/m2K. The existing cast iron radiators, pipes and boilers,
which had been converted from coal to oil in the 1930's were replaced with a modern multizoned system with a full Building Energy Management System (BEMS) heated by
condensing gas boilers. The all new electrical installation included high efficiency lighting
1
The Sir Robert Grieve Award for Sustainability, 1999. A Scottish Regeneration Award 1999 and a mention
in the Civic Trust Awards 1999
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with local, central and presence detection controls, While the building allows occupants to
control their environment through local heating controls and natural ventilation, background
ventilation with heat recovery is also provided to minimise the need to open windows for
fresh air during the heating season. On the top floor this system pulls intake air from
underneath the roof slates which on sunny days act as plate heat exchangers and delivers an
average solar temperature gain of 6°C. In addition much of the roof drains into a large
rainwater harvesting tank. The water is filtered and used to flush half of the toilets in the
building. This has considerably reduce the amount and therefore the cost of supplying water
and attendant sewage costs.
Figure 3: Energy Consumption before and After FM
Figure 4 Solar Slate System © Burnett Pollock Ass
When first completed the client did not have a Facilities Manager (FM) in place and Norton
Park had a number of commissioning problems which were highlighted by a UK government
monitoring study (BRESCU Case Study 127). Over a period of 3 months a newly appointed
FM reduced the overall energy consumption by 40% to the point where Norton Park out
performed what was then considered to be best practice for new offices in the UK. In 2013
Norton Park was again studied using the three main Post Occupation Evaluation (PoE)
methodologies which have been developed in the UK since 1999. Based on 5 years of meter
readings it was possible to estimate the payback of the energy and water efficiency measures
based on 2013 costs. They also highlighted a localised summertime over heating problem,
which was solved by simply opening the inner windows for night time cooling.
Aside from the Energy targets set by the client at the outset of the project Norton Park also
incorporated strategies to minimise waste on site, the reuse of materials and included low
toxic benign materials in the refurbishment. For example untreated timber, low VOC paints,
natural fibre carpets, linoleum etc. The result is an exceptionally good IEQ reflected in the
positive response by the building users in the PoE studies carried out. The most recent studies
show that by and large the current FM staff are continuing to run the building efficiently and
use their own monitoring procedures to pick up any spikes in energy and water use to
investigate and solve problems quickly. Norton Park has maintained an almost 100%
occupancy rate and there is a list of organisations wanting to move in.
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Summary
The buildings presented have demonstrated to be both best practice as new buildings and
operated buildings in terms of sustainability and energy efficiency. However, it is obvious
that even these buildings need a certain time until they will operate (nearly) the same way as
intended. There are various reasons which should carefully be taken into consideration:
1. Energy Demand versus Energy Consumption: Most countries have set limits for the
energy demand of buildings. All (new) buildings have to fulfill these standards. Buildings
focussing on sustainability often fall significantly below these required limits or generate
energy on-site. The buildings presented follow this maxim. With three buildings the
energy demand is higher in building operation compared to the design predictions. This is
a usual effect in the first few years and will be detected by monitoring. Consumption is
normally higher than energy demand because it includes the considerations of system
efficiencies (COP) and user behaviour which both cannot be predicted properly.
2. Concepts of Energy Monitoring: By energy monitoring the compliance of the high
requirements on building performances can be checked. Proper monitoring will help the
operator to detect and remove the weak points of HVAC systems. A well-conceived
monitoring has to be planned already in the design phase. In all of the presented projects,
except Main Customs Office a monitoring has been executed and its benefit is explained
in the project descriptions (e.g. Aéropolis II). Sophisticated monitoring concepts consider
the separated metering of power consumption for electric lighting and distinguish between
building related consumption and plugloads which generally exclude building energy that
is attributed to major end uses (HVAC, lighting, water heating, etc.). Moreover, they also
analyse thermal and visual comfort issues such as operative temperature, luminous
densities and daylight factors. Monitoring results or at least data of the current building
performance serve as a lifelike basis for the key performance indicators of SB Challenge.
3. Optimized Building Operation: While an energetic monitoring will provide information
on the real performance, the optimization of building operation is necessary to tune the
performance as intended. A permanent target-performance comparison is recommended
not only for the first stage of occupancy but also for long term in order to guarantee the
expected energy and comfort benefits for the entire life-cycle of the building.
4. Material & Waste: As the results of the presented projects indicate, the use of recycled
and re-used materials is still in its infancy. One reason might be missing regulations,
standards and guidelines. The use of (recycled) material is being respected more and
more, especially by the trend towards life-cycle assessment (LCA). By use of an
assessment system on sustainable building ( 6) an obligation occurs for LCA that
addresses the usage and environmental quality of material and surface treatment. The
handling of waste issues is not a main issue of sustainable building design routines yet.
Nevertheless it is common practice to avoid waste as much as possible and waste
separation is a matter of course. However, there are no metering concepts by now, except
gathering volumes and bills for waste disposal.
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5. Indoor Environmental Quality, IEQ: One of the main topics of sustainable buildings is
a high IEQ. High air quality, thermal and acoustic comfort provide a proper basis for user
comfort on high level. These buildings enjoy higher esteem by users and will stay of value
in case of selling. A high indoor environmental quality is a key feature of all the projects.
6. Assessments / Certifications: The results show that on the one hand buildings do not
need an assessment necessarily to be sustainable, but certification can ensure the
compliance of sustainable building principles as one can see at the Main Customs Office
or the Paul-Wunderlich-Haus in particular. Sustainable Building Certification should be
applied as a proper instrument for optimisation all over the project phases in order to meet
the original project targets required and authorized by the client. Most important is the
continuity of project attendance from the very beginning by an experienced expert on
sustainable building. By this way both will be facilitated, the project goals and the
integrated design process which are prerequisites for the development of successful
sustainable buildings.
7. Cost Consideration:
650
2300
Building Costs [€/m² NFA]
2.000
High Cost Level
240
1.500
0
Construction
HVAC
High quality below
moderate cost level
Low Cost Level
HzA HH
niedrig
low
BMUB
PWH
high
500
moderate
730
920
350
1.000
Moderate
Cost Level
Reference Costs
The figure shows that most of these energy ambitious projects - Paul-Wunderlich-Haus was also a
project within the German Funding Initiative - performed cost efficient as well referred to the Costs of
the German Building Cost Information System (BKI) In order to compare the projects seriously the
costs have been related and transformed to the reference year of 1999. Thus, sustainable and energy
efficient buildings will not necessarily produce higher costs compared to standard buildings.
The increased initial cost performance of the German BMUB project (the sole Ministry building in
this comparison) is caused by extra costs of the complete refurbishment of the old building part, very
difficult soil conditions and the high-spec office standard for Ministries in general.
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