Deliverable Report Deliverable No.: D2-07 Work Package No: 02 CONCERTO INITIATIVE SERVE

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1 Project Acronym: SERVE REF EC: (Project Number) TREN07/FP6EN/S / REF (project coordinator org.): DOCUMENT: REF.: Project Coordinator: Seamus Hoyne Project coordination org.: Tipperary Rural and Business Development Institute Date: 20th December 2010 Revision: Final Deliverable Report Deliverable No.: D2-07 Work Package No: 02 CONCERTO INITIATIVE SERVE Sustainable Energy for the Rural Village Environment Case Study Eco Village New Building Construction Date: 20th December 2010 Author: Shane Barrett Version: Final CONCERTO is co-funded by the European Commission

2 Table of contents 1 INTRODUCTION HOUSE DETAILS DESIGN & BUILD GENERAL OVERVIEW BUILDING ELEMENTS Foundation Walls Timberframe Hemplime Roof WINDOWS & DOORS SPACE HEATING & HOT WATER VENTILATION HOUSE PERFORMANCE INDICATORS PERFORMANCE OF HEATING SYSTEM ELECTRICAL USE PERFORMANCE OF HOUSE MEASURED AGAINST NATIONAL BUILDING REGULATIONS U-Values Air Tightness Energy Rating Performance of House BUILDING ENERGY DATA APPENDICES APPENDIX 1: QUINNTHERM 150MM DH BOARD TECHNICAL DETAILS APPENDIX 2: QUINNTHERM BLOCKS TECHNICAL DETAILS APPENDIX 3: MAGNESIUM SILICATE BOARDS TECHNICAL DETAILS APPENDIX 4: BBA APPROVAL TESTING INSPECTION CERTIFICATE; TRADITIONAL HEMPCRETE WALL SYSTEM APPENDIX 5: TEST REPORT FROM NATIONAL PHYSICAL LABORATORY; THERMAL CONDUCTIVITY OF HEMP & LIME. 19 APPENDIX 6: TRADICAL HEMPCRETE U-VALUE DATA SHEET APPENDIX 7: BITROC BOARD TECHNICAL DETAILS APPENDIX 8: SAMSON WINDOWS/DOORS TECHNICAL DETAILS APPENDIX 9: PROAIR TEST CERTIFICATE APPENDIX 10: BUILDING CONTRACTORS SERVE 2

3 1 Introduction Site 91 at the Eco Village in Cloughjordan is a fully serviced detached site. The owners and developers of the site received full planning permission from North Tipperary County Council to construct a two story 170m2 dwelling. The site runs along an east west axis of the village development with some elevation offering a good aspect for solar gains. The house has been designed where the main living & bedrooms are oriented south with 50% of the total glazing area facing south and only 10% facing north. Figure 1-1: House at Site 91: North Elevation SERVE 3

4 2 House Details Design & Build 2.1 General Overview The construction details of the house are as follows: o - A two story detached building with a pitched roof and a single story annex with a flat roof constructed on the east side to provide utility services & food storage. - The building has 4 bedrooms, kitchen, living, study, bathroom and WC. - The construction materials consist of o Ground floor insulated strip foundation o Hemp Lime external walls o Pitched roof with unoccupied attic space, insulated with cellulose insulation. Roof slates are recycled rubber and Windows are energy efficient timber frame triple glazed with argon filled low emissivity glass. The doors are high specification sealed timber doors. - Total floor area = 170m2 - Provisional BER rating of A3 or 72.5 KW/hrs/m2/yr 2.2 Building Elements Foundation The house has a traditional strip foundation built up with concrete blocks with hardcore filling between the strips and a sand base to support the poured concrete floor slab. Figure 2-1: Foundation showing Quinntherm insulation There is a 150mm of Quinntherm High Density Insulation installed under the 150mm floor slab (see Appendix 1 for product data). Quinnlite aerated blocks were used around the perimeter of the slab and in conjunction with the edge insulation to eliminate potential thermal bridges between the floor and external walls (See Appendix 2 for product data). The U value of the floor worked out at 0.13 W/m 2 K. The maximum U-Value allowable under the Building regulations which the SERVE project is measured against is 0.25 W/m2K. SERVE 4

5 Figure 2-2: Radon Barrier & Edge Insulation Figure 2-3: Concrete floor being laid above insulation. Randon barrier evident at sides of foundation SERVE 5

6 2.2.2 Walls The walls are constructed using a Hemp/Lime mix encasing a timber-frame skeletal structure as in the drawing below. The U-value of the wall construction is 0.22 W/m 2 K. The maximum allowable U- Value under the Building Regulations which the SERVE project is measured against is 0.27 W/m2K The build up of the wall (from inside to outside) is 1 = internal multi pro manganese silicate plaster board 2 = Timber frame structure 3 = Hemp/lime wall infill finished with an external render Figure 2-4: Hemp Lime wall build up Timberframe The first stage of the wall construction was to erect a timberframe shell that is strong enough to provide the full structural support for the house. The timber frame was designed so that a solid hemp lime wall could be cast around it. The timber frame was supplied in modular form and erected on site with a crane. All external walls on the inside were sheathed with medium density multi-purpose Manganese Silicate boards, which when combined with the frame provide the structural and racking strength. This board is a highly durable non combustible board for use in applications combining sound insulation, moisture resistance & performance against fire (See Appendix 3 for details). The timber-frame was installed in 2 stages with the walls erected first and the roof trusses installed after the hemp lime in-fill walls were completed. Figure 2-5 : Timber Frame Construction SERVE 6

7 Hemplime The external walls of the house were cast from hemp and lime. Hemp comes from industrial hemp and is an annual crop which has a multiple uses. For building, the wood part of the hemp stalk is used. The hemp/lime mix is an established walling material for carbon negative highly thermally efficient walls which have the following advantages over traditional building materials: Figure 2-6: Hemp Mix Hemp/lime mix absorbs CO 2 in its manufacture and so has a negative embodied CO 2. The Hemp/Lime mix is made from renewable UK grown hemp based materials. The Hemp/Lime mix is highly insulating resulting in thin walls with a very low U value ideal for meeting the higher levels of the Building Energy Rating required by SERVE project. Unlike other insulators a hempcrete wall also has thermal inertia similar to thermal mass and so houses built of this material can change temperature very slowly reducing heating loads significantly below lighter weight buildings with the same U value. The Hemp Lime mix is vapor permeable and when used with lime based renders and plasters creates a breathable walling system for healthy living. The material was sourced through Lime Technology in the UK as their hemp lime mix is fully tested and certified (See also Further technical details are provided in Appendix 4: BBA Approval Testing Inspection Certificate; Traditional Hempcrete wall system. Appendix 5: Test Report from National Physical Laboratory; Thermal Conductivity of Hemp & Lime Appendix 6: Tradical Hempcrete U-Value Data Sheet During construction the walls were cast using lightweight plastic shuttering to form 300mm thick exterior walls. The walls were cast up to wall plate height as the attic space adjacent to the gable walls will be unoccupied. It took 2 weeks to complete these walls. SERVE 7

8 Figure 2-7: Wall build up method Roof The roof is a shallow pitched roof of 25 degrees and the attic space will not be used as a living space. The roof trusses were installed after the hemp lime wall was complete. The gables are made up of un-insulated timber frame walls as the attic space is unoccupied. Wood fibre Bitroc boards were installed over the external face of the rafters to act as a breathable vapour barrier The Bitroc boards are a bitumn impregnated wood fibre board which add good racking strength and thermal insulation qualities to a building (see Appendix 7). Counterbattens were then fitted across the wood fibre board and the roof was slated with recycled rubber tiles. The main attic has been insulated at ceiling level with 400mm of Cellulose achieving a U value of 0.13 W/m 2 K. This roof construction (pitched roof, insulation horizontal at ceiling level) under the Building Regulations which the SERVE project is measured against has a U-Value of 0.16 W/m2K. SERVE 8

9 Figure 2-8: Roof Construction 2.3 Windows & Doors All windows are timber frame triple glazed with argon filled low emissivity glass. The doors are high specification sealed timber doors. The windows were supplied by local glazing company Carey Glass and have a certified U-Value of 1.2 W/m2/K (See Appendix 8: Samson Wood Tilt & Turn Test Result Report.) Figure 2-9: Glazing sealing mechanism 2.4 Space Heating & Hot Water The space heating demand for the house is supplied from the District Heating Network of the Eco Village. The house has installed an 800litre buffer tank which provides both space heating and domestic hot water. A house station control unit is fitted adjacent to the hot water cylinder which monitors the hot water requirement of the house on a 24hr basis. The provisional heat load for the house is very low at 20 kwh/m2/yr. Based on this it was decided to install low temperature aluminium radiators through out the house. The radiators have been specifically sized for each room and it is also felt that they will be more responsive to meet the infrequent heating requirements of the house. The other key advantage is that it will cost about 50% less underfloor heating. There are 2 heating zones installed to control the temperature on both the North and South sides of the house. SERVE 9

10 Figure 2-10: Heating Buffer Tank (left); Heat exchanger and meter (middle); radiator (right) Hot Water will be controlled by a separate zone to provide time and temperature control. All showers will be fed directly by the hot water supply and eliminate the need for electric showers. The house has been designed to ensure the bathrooms and kitchens are close to the hot water tank to eliminate dead legs. 2.5 Ventilation The house has a heat recovery ventilation system installed to provide a constant supply of fresh air to the house. The unit is manufactured in Co. Galway by ProAir Systems. The heat recovery unit is a ProAir PA600 and performs to 90% heat exchange efficiency with one kitchen and two wet rooms. (See Appendix 9: ProAir PA600 Test Certificate) For this system to work effectively the house has to be very air tight. There has been a lot of emphasis placed on sealing all gaps around openings and fitting a membrane at ceiling level to reduce air loss through the ceiling. Figure 2-11: Heating Controls Figure 2-11 Ventilation Unit in Attic Space A good practice air tightness value of 3m 3 /hr/m is being targeted by the SERVE project. This house completed an Air Tightness Test once construction was complete and achieved a result of SERVE 10

11 3 House Performance Indicators 3.1 Performance of Heating System Actual recorded data relating to the space & water heating requirement of the house is available for the 6 month period April 2010 to September The heating demand in that period was 1,739 KW/hrs. The provisional BER estimate for the space heating demand for the house was 2,646 KW/hrs per year. With the Domestic Hot Water requirement estimated at 2,974 KW/hrs. The total heating demand was estimated at 5,620 KWhrs. In the 6 month period of monitoring to date the house has had a combined space & hot water requirement of 31% of the annual estimated demand. Space & DHW Heat Requirement - 6 Months - Site Monthly Usage (kwh) Daily average (kwh) April May June July August September Total YTD Electrical Use Figure 3-1 Space & Domestic Hot Water Energy Use The data outlined below shows the electrical use in the house in a 6 month period of occupancy from May 2010 to October The total electrical usage was 1697 KW/hrs in that period which includes electric cooking. The target electrical energy consumption of houses built to the Eco Village Eco Charter is 7KW/m2/yr lighting & 7KW/m2/yr cooking & other appliances. Site 91 has a target of 2,380 KW/hrs/yr. The electrical consumption to date is 71% of annual electrical energy target. At present there is no facility in the house to determine the proportion of electrical energy that is consumed by cooking appliances. Electrical Usage including Cooking - 6 Months - Site Monthly Usage Daily Usage May June July August September October Total YTD Figure 3-2 Electrical Energy Use SERVE 11

12 m3 50 Pa Deliverable Report 3.3 Performance of House measured against National Building regulations U-Values The critical performance indicators determining the energy efficiency of the house are the floor, wall & roof thermal efficiencies. When measured against national building regulations, Site 91 has improved the U-Value of these elements by the following: Floor improved by 48%, Wall by 18% Roof by 19% Air Tightness Air Tightness of the built houses in the Eco Village was emphasised as a critical area in terms of achieving high performance energy efficient houses. Air Pressure tests have been part sponsored by the SERVE project and a target air tightness target of 3.0 m3 50Pa introduced. This value is a 70% improvement of National Building Regulations. Site 91 performed an Air Tightness test on completion and achieved a certified air tightness value of 1.12 m3 50Pa Air Permeability Air Permeability Site 91 SERVE Building Regulations 2006 Figure 3-5 Air Tightness Energy Rating Performance of House Houses built in the Eco Village under the SERVE programme are required to have a Heat Energy Rating 30% below 2006 National Building regulations which is 100 KW/hrs/m2/yr. Site 91 has exceeded the national target by almost 60%. SERVE 12

13 KW/hrs/m2/yr Deliverable Report Delivered Energy Rating Delivered Energy Rating Site 91 SERVE Target Building Regulations 2006 Figure 3-4 Annual Heat Energy Rating 3.4 Building Energy Data The table below shows the values of the various building elements of Site 91 measured against the various requirements within the National Building Regulations. Element Value Site 91 Building Regulations 2006 Floor W/m2/K Wall W/m2/K Roof W/m2/K Glazing W/m2/K Thermal Bridging W/m2/K Air Changes Air Changes per Hour Air Test m3 50 pa Heating Controls Time & Temperature (Y/N) Y Y Heating Controls Zones 2 2 Boiler Efficiency % EE Lighting % BER Rating A - G A3 C2 Energy Rating kwh/m2/hr Figure 3-6 Dwelling Element Values Comparison SERVE 13