BUILDING REGULATIONS PART L 2011 PROVISIONS & COSTS (STANDARD 3-BED SEMI-D, CIRCA 120 SQM)

Transcription

1 BUILDING REGULATIONS PART L 2011 PROVISIONS & COSTS (STANDARD 3-BED SEMI-D, CIRCA 120 SQM) NOV 2012

2 OVERALL PRIMARY ENERGY, CO 2 & RENEWABLES TGD L / ? CO 2 % 100% 69% 46% 30%? PRIMARY ENERGY % 100% 60% 40% 25%? PRIMARY ENERGY (APPETITE) FIGURE (kwh/m²/yr) (BER C1) (BER BI) (BER A3) 38-40? (BER A2) RENEWABLE REQUIREMENT (kwh/m²/yr) 0 10* 10*? BER RANGE C1 B1 A3 A2? * 4 kwh/m²/yr if renewable generates electrical energy (e.g.photovoltaic)

3 U-VALUES (W/m²K) GENERALLY REQUIRED TO ACHIEVE PART L COMPLIANCE 3 bed semi, 2011 & 2013 figures assume heat recovery ventilation system is included and airtightness circa 0.3ac/h (approx required insulation thickness in brackets) / ? WALL 0.27 (50 mm) (60+mm) * (APPROX100mm) (APPROX150mm)? FLOOR 0.25 (60mm) 0.20 (70-80mm) * (100+mm) (140mm)? ROOF 0.20 (235mm) 0.16 (265mm) * (300+mm) 0.12 (360+mm)? WINDOWS DOORS * 1.0? (TRIPLE GLAZING) Wall and floor insulation is assumed to be phenolic foam. Roof insulation, placed between and above ceiling joists, is assumed to be quilt insulation roll. Percentage of glazing to floor area ratio should not exceed 30% without special consideration of glazing U-values. *Specifying to the max. allowable elemental U-values in Table 1 of TGD L 2011 is unlikely to achieve 2011 compliance. Values (2011) indicated above are superior to Table 1 values. * If heat recovery ventilation is not provided an improvement of circa 20% from the U-values shown above is likely to be required for 2011 compliance. (triple-glazed windows and an increase in wall insulation thickness probably requiring cavity widths exceeding 110mm).

4 STUDY OF THE EFFECT OF COMMON DESIGN OPTIONS AND TECHNOLOGIES ON THE ENERGY APPETITE (BER) OF A TYPICAL SEMI 2011 Performance figures / costs quoted are approximate may vary with market conditions, available technologies, suppliers etc circa 120m² semi detached house Ground Floor Plan First Floor Plan 4

5 SITE PLANNING, ORIENTATION & HOUSE SHAPE North South V East West Orientation Effect on appetite / BER for standard semi is likely to be limited unless opes are downsized on colder orientations

6 House design altered to deliver small openings in north elevation & larger openings in south elevation Possible effect on appetite / BER -2 to -5 kwh/m²/yr (depends on size / performance of windows etc) 6

7 Shape and exposed surfaces Possible effect on appetite / BER (basic shape compared to L shape) -5 kwh/m²/yr approx Internal Draft Lobby External Draft Lobby Effect on appetite / BER -2 kwh/m²/yr -1 kwh/m²/yr Conservatories Possibly no change in appetite / BER (e.g. conservatory separated) 7

8 Chimney or flue Effect on appetite / BER calcs Open coal fire can add 13kWh/m²/yr in DEAP calcs Sealed gas fire can add 5kWh/m²/yr in DEAP calcs Flueless gas fire can add 3kWh/m²/yr in DEAP calcs (see also Renewables 8 Biomass below) V V 8

9 Thermal Mass (e.g. concrete floors etc) Effect on appetite / BER Low Medium -1 kwh/m²/yr Medium High -1 to -2 kwh/m²/yr Air Permeability Effect on appetite / BER possibly -5 to 8 kwh/m²/yr depending on performance achieved Max. allowed air permeability (2011): 7m³(h.m²) = 0.35ac/h Practically 5-6m³(h.m²) = ac/h can be achieved but site installation standards must be high 9

10 SERVICES & GREEN ENERGY (RENEWABLES) 1. Energy efficient light fittings 2. Boiler efficiency SIZING POSSIBLE CHANGE IN APPETITE / BER COMMENT 100% provision -10 kwh/m²/yr Low capital cost Increase efficiency 90% -10 kwh/m²/yr Requirement TGD L 3. Heating controls Control of temp, time & zone independently -3 kwh/m²/yr Temp. control of 2 zones requirement of TGD L 10

11 4. Heat recovery Mechanical ventilation heat recovery (MVHR) used for whole house Approx (currently not accepted as renewable ) Less circa kwh/m²/yr (some suppliers claim 30-35) 7 year payback (suppliers claim) 5. Solar thermal Circa 5m² solar thermal panels provide 50 70% of household hot water. Approx mostly suitable for house area up to circa 150sqm Less circa kwh/m²/yr can provide full renewables requirement 3-5 year payback (suppliers claim) Probably in excess of 10 years 11

12 6. Solar photovoltaic 7. Air source heat pump 3m² solar PV would provide enough electrical energy to produce 4kWh/m²/yr of household electricity, 3m² PV approx can provide full renewables requirement 5 year payback claimed (some of surplus energy produced may be sold to the national grid - if smart metering available) In theory produces 100% of household hot water & space heating, replacing convention boiler. Approx. 6,000-9,000 possibly kwh/m²/yr. can provide full renewables requirement 4 5 year payback claimed 12

13 8. Biomass Individual biomass boilers are probably not an option for housing developments due to the volume of storage required. However, biomass room heaters may be an option instead of an open or gas fire. Approx Provide approx 2kWh/m²/yr of renewable energy requirement however the appetite / BER will increase by +4kWh/m²/yr in DEAP calculations. Payback depends on how often it is used as a secondary space heat or water heat source. General Note 1: GEOTHERMAL (ground source heat pumps) not considered in this study due to the generally limited plot size in housing developments General Note 2 Detailing to limit Thermal Bridging is a requirement of TGDL 2011 (& 2007/2008). Performance exceeding basic requirements can deliver reductions in the region of 6 10kWh/m²/yr calculation evidence may be required and site installation standards must be high. 13

14 ESTIMATED COSTS (Nov 2011) 2011 Part L for typical 120sqm semi-d. E.O. costs over 2007/8 Part L Provisional order of costs figures, all nett of VAT. Some builder / developer rates may differ. Assumption: 2007/8 house has circa 5sqm solar panels (renewables) and 2011 house has similar. Option 1: Medium increase in insulation provision and fit HRV. (Double glazed, low-e glass performance W/sqmK) Insulation e.o circa 1.0k-1.5k HRV cost circa 4k Airtightness performance increase circa (e.o 2007/8 Part L) 0.5k - 1.0k (supervision etc) Total circa k Option 2: Large increase in insulation provision (no HRV) Insulation e.o circa 2.0k 2.5k Increased cavity size, ties, window boards, closers, foundations etc circa 2.5k 3.0k Airtightness performance increase circa e.o 2007/8 Part L) 0.5k - 1.0k (supervision etc) Triple glaze windows (e.o double glaze) 1k 1.5k Total circa 6k - 8.0k 14