2Building Energy Rating Construction StudiesAn introduction toBuilding Energy Rating
3Building Energy Rating Building Energy Rating (BER) grades the energy efficiency of a buildingA Dwelling with a high rating will save the owner/ occupier money in energy costs.
4Important dates for the BER BER required for:New dwellings that apply for planning permission on/after1st. January 2007.All existing buildings offered for sale or rent from 1st. January 2009.
5Building standards & energy use Typical for Building Regs Part L 2005Building Regulations2007/08Primary Energy kWh/ m2 per yearLow/ Zero CarbonIrish construction standard/year
6Main factors effecting BER Thermal insulation of the building envelope.Heat gains through glazed openings.Ventilation and air permeability.Domestic hot water system and control.Space heating control and energy required.Lighting and internal heat gains.6
71 kWh of electricity costs 18 cent What does BER measure?The BER measures energy use per square meter (floor area) of the dwelling per year.Measurement UnitkWh/m2/yr1 kWh of electricity costs 18 centKilo watt / hour
8Energy labelling informs the consumer of costs. Domestic AppliancesEnergy labelling informs the consumer of costs.
9What is Building Energy Rating? BER ratingCalculated using DEAP software.DEAP – Dwelling Energy Assessment ProcedureBER scale (kWh/m2/yr) A1,A2,A3,B1,B2,B3 etc.CO2 indicator (kg/m2/yr)
10Building Energy Rating (BER) Label Each full band is 75 kWh/m2/y and is indicated by a change of colour on the label.FULLBANDEach small band is indicated by a change in the grade. Example:A1 to A2 to A3
11Energy Costs and BERCost comparasions based on average energy costs for 2007 in a 250m2 dwelling
12Current Building Regulations A dwelling built to the 2007/08 building regulations should achieve a:B or C rating
13Building Energy Rating (BER) ? No obligatory minimum standard applies.BER must be produced by a registered BER Assessor.BER is valid for 10 years unless changes are made to the building.The BER is independant of how the occupants behave in the building.An advisory report must accompany a BER certificate13
14Accompanying Advisory Report New build:To advise owners on how to use the features in the building to maximise energy efficiencyExisting buildings:To advise owners on the options for upgrading of building to maximise its energy efficiency
15DEAP Computer Software Calculating the BERDEAP Computer SoftwareDownload from:
16Information required for DEAP 45 individual inputs are needed to do a BER assessment on a dwelling on DEAPEnergy used for lightWall Heat LossDwellingReferenceLiving AreaHeated to 21°Heat gains and losses through windowsDoor heat lossConstruction typeCentral Heating DetailsDomestic Hot Water DetailsVentilationHeat loss through thermal bridgesRoof Heat LossFloor Heat Loss
17Information required for DEAP 1. Dimensions:The internal dimensions of the building envelope.New dwellings can be measured from the plans.Existing buildings may need to be surveyed.
18Information required for DEAP Number of chimneys/flues2. Ventilation DetailsNumber of sheltered sidesNumber of fans and ventsPresence of a draught lobby or porch.Method of ventilation:Natural or Mechanical
19Information required for DEAP 3. Air PermeabilitySealing of the building envelope.Blower door testing required on new dwellings.Required to be 10 m3/(h.m2) for new 50 pa.
20Information required for DEAP 4. Building elements (fabric heat losses)Ceiling/Roof U-ValueWall U-ValueFloor U-ValueDoor & Window U-ValuesThermal bridging factor typical 0.11 W/m2K
21Information required for DEAP 5. Glazed area heat losses and gainsGlazed area sizes.Orientation.Glazed unit U-Values- Glazing- FrameSolar transmittance.
22Information required for DEAP 6. Details of the hot water systemLevel of Insulation on storage cylinderInstant or storage system.Insulation on pipe work.Temperature and time controls.
23Information required for DEAP 7. Boiler and space heating detailsBoiler efficiency %Heating controlsRadiator’s or under floor heatingFuel used
24Information required for DEAP 7. Boiler and space heating details contd.Insulation on pipe work.Temperature and time controls.Weather compensation controls.
25Information required for DEAP 8. Renewable energy used, e.g.Solar Water heatingSolar photovoltaicGeothermal energyWind power
26Information required for DEAP 9. Lighting provision in the dwelling.The percentage of energy efficient light fittings in the dwelling.
27Information required for DEAP 10. Net space heat demand.The heating requirements for the dwelling will depend on:The total volume.The living area %.Living area is assumed to be heated to 21oC and the rest of the dwelling heated to 18oC.
28Information required for DEAP 11. Thermal mass category of the building ranging from:Thermally light construction e.g. timber frameThermally massive construction. e.g.concrete block with hollowcore.
29Energy rating worked example Download the DEAP software from:Install the software as per instructions.Use the software to do a sample rating on the sample dwelling using the data supplied.Vary the inputs to improve the rating.