D 4.4 Activity Report Technical support during the planning phase of new buildings

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1 Grant agreement no. IEE/11/981/SI MLEI BEAM-Graz City of Graz (AT) Boosting Energy Efficiency Actions in the Municipal Buildings of the City of Graz D 4.4 Activity Report Technical support during the planning phase of new buildings D 4.4 Activity report planning phase new buildings Page 1 of 11

2 Table of Contents 1 Introduction Objectives Main activities and lessons learned Supported projects Elementary school Mariagrün (Passive House standard) Objectives Activities Results Elementary School St. Peter (appendix to an old school building) Objectives Activities Results D 4.4 Activity report planning phase new buildings Page 2 of 11

3 1 Introduction 1.1 Objectives The City of Graz has made in his sustainable energy action plan the commitment, that all new buildings from 2015 on will meet the requirements of nearly zero energy standards (EU target 2020 and EPBD II regulation). The task within this work package was to make the new buildings sustainable and energy efficient and to show the way towards nearly zero energy buildings. Most of the new buildings within BEAM Graz project are substitutions for old and non efficient buildings because renovation would not be cost effective anymore and does not fit the needs. For example the primary school Schönbrunngasse is the replacement for the old primary school Mariagrün (19th century). The planning phases of two new buildings have been accompanied from an external impartial partner to secure the high targets and quality standards. Graz Energy Agency (GEA) was the executive subcontractor for this task, experienced in the attendance of the planning phase of new buildings. The accompanied new buildings have been built with a good energetic standard (better than the level which is required by the Styria building legislation) with higher investments in energy saving and CO2 reduction measures showing the way towards nearly zero energy buildings. The planning phase is crucial for the built standards of new buildings. 1.2 Main activities and lessons learned The needs and depth of attendance depend on the existing know how in building energetic high standards of the planning architect. The two projects showed great differences in the depth of knowhow and focus to realize high energetic standards. The architect of the primary school Mariagrün was an experienced Passive House planner from Vorarlberg (highest density of Passive Houses in Austria), therefore the detailed questions focused on RES and the possibilities of nearby energy supply systems. The focus of the attendance of the second project (primary school St. Peter) was to reduce cooling demand and the significant energetic improvement of the initial design (from class C to class B with option to A). D 4.4 Activity report planning phase new buildings Page 3 of 11

4 2 Supported projects 2.1 Elementary school Mariagrün (Passive House standard) Figure 1: New elementary school in the garden of an old child care centre ( GBG/Markus Kaiser Graz) Objectives The primary school Mariagrün has been rebuilt at the site Schönbrunngasse. The architectural contest (with energetic assessment criteria) and the first planning phase had been completed. The contest and the first planning were supervised on energy by the Graz Energy Agency. The aim was to supervise the detailed planning phase and accompanying the realization. The aim was to build the building in passive house construction and to achieve the GOLD standard of the Austrian klimaaktiv Climate Initiative Activities During the planning phase a huge number of detailed questions had to be tackled it was a steady flow of work, which is not documented in detail here. In parallel to the work of Graz Energy Agency also specialized planners for buildings physics, HVAC systems and ecological materials had been engaged. The main activity was to secure the target of klimaaktiv GOLD standard and to reach the certified Passive House standard. D 4.4 Activity report planning phase new buildings Page 4 of 11

5 The criteria to reach the klimaaktiv GOLD standard are very high and contain specifications on the topics of Energy efficiency, Health and user comfort, Avoidance of environmentally harmful construction material, and High construction quality. The focus of the supervision of the external partner Graz Energy Agency was on the following points: Examination of the existing planning, especially regarding building technology and energy optimization clarification of open points with the planner Qualitative assessment of design variants during planning meetings suggestions to hand the Austrian Climate Initiative set of criteria (klimaaktiv GOLD standard targeted) Ongoing analysis of the current planning with regard to the energy improvement and the climate: active criteria Development of detailed targets for the construction on the basis of the permit application Discussion of the klimaaktiv target values and specifications with the building owner and planners Development of planning alternatives to reach klimaaktiv GOLD standard Participation to planning meetings in the detailed planning phase Discussion of proposals with the planners and the building owner GBG during the planning meetings Review of the submission documents on implementation of the goals (GOLD standard according to the Austrian klimaaktiv building standard) Submission to the klimaaktiv Clearing House and accompanying the certification procedure Verification on the basis of invoices or site inspection, that the measures have been carried out in accordance with the klimaaktiv design specifications In the following chapter, some of the results of the work are presented Results The elementary school Mariagrün is the first school built in Passive House standard in Graz and has been certified from the Passive House Institute. The main results are: Class A++ in the national energy certificate for buildings (9.45 kwh/m² and year) 921 of 1000 points in the Austrian Climate Initiative set of criteria GOLD standard On the way to these results detailed questions had to be clarified. For example at the beginning the target was to realize a PV system, but the school lies within a park with high and old trees. So the task was to analyse the shading to answer the question of efficiency of the D 4.4 Activity report planning phase new buildings Page 5 of 11

6 planned PV system and the economical parameters. Unfortunately the shading of the trees was too much and the old trees are under protection the PV system was not realized, the solar yield too low. 90 Sonnengang beim höchsten Sonnenstand 45 Tages- und Nachtgleiche 30 Tiefster Sonnenstand Nord Ost Süd West Nord Figure 2: Shading analysis and PV System simulation (shading and economic analysis) D 4.4 Activity report planning phase new buildings Page 6 of 11

7 A second question to answer was which heat supply system is best. During the planning phase four variations of the heat supply system have been investigated economically (life cycle cost analysis): Ground source heat pump with ground collectors Geothermal heat pump with deep probes Air heat pump Gas condensing boiler The result was that the gas condensing boiler has the lowest life cycle costs within 20 years (including a new boiler after 15 years). The boiler was realised in the existing boiler room of the nearby kindergarten. Figure 3: Life cycle cost analysis of the heating system D 4.4 Activity report planning phase new buildings Page 7 of 11

8 Figure 4: The school in use postcard from the Austrian klimaaktiv Climate Initiative ( klimaaktiv) The school with 921 of 1000 points and GOLD standard in the federal ecologic klimaaktiv building rating was nominated to the Architectural State Award The children enjoy their new school and feel the results of the done work (Figure 4: School can be so beautiful ). D 4.4 Activity report planning phase new buildings Page 8 of 11

9 2.2 Elementary School St. Peter (appendix to an old school building) Figure 5: Enlargement and modification of the existing primary school (built in 1885), additional 1943 m² floor space (GBG) Objectives The VS St. Peter received an extension with 4 classes and 2 group rooms. The requirements of the architectural contest and the preliminary design were to build the annex according to building code standards. At the beginning of the BEAM Graz project the architectural design was already fixed (result of a design contest in 2008 with a limited number of invited architects) and the first planning stage for permission was finished. The first planning phase of the detailed planning has also been completed; the planning stage had been very far, therefore time constraints high. The aim was to accompany the further planning by Graz Energy Agency and to develop easy going suggestions for energetic improvement measures. D 4.4 Activity report planning phase new buildings Page 9 of 11

10 2.2.2 Activities Graz Energy Agency analysed the existing planning and made suggestions for energetic improvements. On basis of the permit application planning, GEA calculated the actual heat demand, analysed the calculation results and examined the plans for (easy going) energetic improvements, which do not influence the architectural design seriously and does not exceed the existing budget by far. The activities in detail: Examination of the existing planning with a focus on energy optimization Calculation the energy performance certificate for the annex Potential analysis and development of measures to optimize the building envelope Qualitative assessment of design variants drafting of proposals for improvement Development of planning alternatives with higher energetic standards Discussion of targets, planning alternatives and specifications with the planner and GBG Attending three planning meetings including preparatory work Results The heat demand before optimization was 54 kwh/m² and year this was class C in the Austrian energy label for buildings. GEA suggested the following improvements: Increasing the insulation thickness of the exterior walls to 16 cm Ground ceiling: Change of materials (levelling compound with insulating material instead of sand) and additional insulation Flat roof: Change of materials towards higher insulating materials (conductivity 0,031 W/mK instead of 0,04 W/mK) Reduction of glass facades, replacement through high insulated walls where possible (sufficient natural light) Improvements of the windows (better frames, triple glazing instead of double glazing) The improvement of the heat demand made 54%. Figure 6: Heat demand before and after optimization D 4.4 Activity report planning phase new buildings Page 10 of 11

11 In addition to the energetic improvement there are several additional advantages: Higher comfort for the pupils by higher surface temperatures in front of large glass areas reduction of the necessary radiators By reducing the glass surfaces, triple glazing with g value 0.45 and replacement of nontransparent panels in the window constructions by massive components more storage masses and save the otherwise necessary sun protection glazing Better light quality, especially in winter by saving the colored and multi coated double solar control glazing The additional costs of the measures had been low (about 1 % of the total costs) and the reduction of heating costs makes more than , in 25 years (more than the additional costs). The CO2 reduction out of the optimization is about 8.5 tons CO2 a year. This example shows, that the optimization towards optimal life cycle costs instead of optimizing the investment costs makes sense. D 4.4 Activity report planning phase new buildings Page 11 of 11