GETTING TO CODE LEVEL 3 THE EASY WAY 1 AUGUST 2011.

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1 GETTING TO CODE LEVEL 3 THE EASY WAY And a Footnote about Primary Energy In some parts of the country the planners require new homes to reach Level 3 of the Code for Sustainable Homes. For this, at least 57 points are required out of the 100 available. (We ve seen how points are scored in earlier articles. For other introductions to the Code, see Further Info.) As we see below, Code Level 1 is there for the taking; and most selfbuilders should be able to get to Level 3 easily enough. Getting to Level 6 is difficult and costly. How to score some easy points Easy points can be gained by: Doing what you would be doing in a selfbuild anyway. Installing efficient fittings/appliances/devices. Doing some admin work. Let s look at each category in turn to see where easy credits, and hence easy points, are there for the taking. Category 1 Energy and CO 2 Emissions Fabric Energy Efficiency 3 easy credits, say. The 2010 revision of Part L1A of the building regulations requires high energy standards, and these usually result in a high Fabric Energy Efficiency. The least number of credits awarded for this is 3, so let s assume we gain these. Energy Display Devices 1 easy credit. Install an electricity monitor. Drying Space 1 easy credit. Install a clothes line. Energy Labelled White Goods 2 easy credits. Install A+ and A rated white goods, with information. External Lighting 1 easy credit. Install standard PIR security lighting (or no security lighting at all). Cycle Storage 2 easy credits. Allocate garage space for cycles. Home Office 1 easy credit. Fit a broadband/phone socket into a suitable room. Total easy credits in this category: 11. Conversion factor: Easy points: Category 2 Water Indoor water use 1 easy credit. It s easy to beat the building regulations requirement by a mere 5 litres/day per person. GETTING TO CODE LEVEL 3 THE EASY WAY 1 AUGUST 2011.

2 External water use 1 easy credit. Install a water butt or you might be installing a rainwater harvesting system, anyway. Total easy credits in this category: 2. Conversion factor: 1.5. Easy points: 3. Category 3 Materials Environmental impact of materials 10 easy credits, say. It s very easy to achieve high ratings under the Green Guide to Specification. Let s say the five elements of the building envelope have an A rating with 2 credits each 10 easy credits altogether. Easy credits in this category: 10. Conversion factor: 0.3. Easy points: 3. Category 4 Surface Water Run-off Management of Surface Water Run-off from the Development 2 easy credits. Install soakaways, use permeable paving for driveway, etc. Flood Risk 2 easy credits. Most plots are in Flood Zone 1, where the risk of flooding is low. Produce a Flood Risk Assessment. Total easy credits in this category: 4. Conversion factor: Easy points: 2.2. Category 5 Waste Storage of Household Waste 4 easy credits. Most selfbuilds have space available outside for dustbins, and inside for recycling bins. Composting 1 easy credit. Install a compost container in the garden, and produce a guide to composting. Construction Site Waste Management 1 easy credit. Produce a Site Waste Management Plan, and divert some waste from landfill. Total easy credits in this category: 6. Conversion factor: 0.8. Easy points: 4.8. Category 6 Pollution Global Warming Potential of Insulation 1 easy credit. Insulation with a high GWP is easily avoided. NOx emissions 2 easy credits. Fit a very clean-burning gas boiler. If you are more ambitious and choose not to have gas central heating, these credits will elude you. But in that case, you will presumably be building an extremely energy efficient home, which will gain lots of extra points in Category 1. Total easy credits in this category: 3. Conversion factor: 0.7. Easy points: 2.1. Category 7 Health and Well-being Daylighting 3 easy credits. GETTING TO CODE LEVEL 3 THE EASY WAY 2 AUGUST 2011.

3 Most selfbuilds are well lit. Sound insulation 4 easy credits. Most selfbuilds are detached dwellings. Private space 1 easy credit. Most selfbuilds have a garden. Total easy credits in this category: 8. Conversion factor: Easy points: Category 8 Management Home User Guide 3 easy credits. For your own benefit, produce guides to using your home and to making the most of the local amenities. Construction Site Impacts 1 easy credit. For example, set targets for the water and energy use on site, and monitor the usage. Total easy credits in this category: 4. Conversion factor: 1.1. Easy points: 4.4. Category 9 Ecology Protection of Ecological Features 1 easy credit. The chances are that your plot doesn t have any ecological features, so you get this credit by default. If the plot does have ecological features, you may well wish to preserve them and the planners might require you to do so, anyway. Change in Ecological Value of Site 2 easy credits. For most selfbuilds, the development is more or less ecologically neutral, and so gains 2 credits. Total easy credits in this category: 3. Conversion factor: Easy points: 4. Summing up Summing the easy points from all the categories above we obtain: Total number of easy points = The table below shows the points necessary to reach each Code Level: Points Code Level Star rating 36 1 * 48 2 ** 57 3 *** 68 4 **** 84 5 ***** 90 6 ****** Points required for each Code Level GETTING TO CODE LEVEL 3 THE EASY WAY 3 AUGUST 2011.

4 With our 45.7 easy points we have easily reached Code Level 1. Scoring extra points to get to Code Level 3 To reach Code Level 3 we need 11.3 extra points ( ). Let s find out where the extra points might come from. Here is a not-too-onerous selection: Category 1 Energy and CO 2 Emissions In the NHBC s Zero Carbon Homes, a pie chart shows the CO 2 emissions from a typical house built according to the building regulations current from 2006 to Water heating 22% Space heating 31% Lighting 9% Pumps and fans 2% Appliances 28% Cooking 8% Sources of CO 2 emissions for a typical modern house According to the pie chart, water heating accounts for 22% of emissions. But in the Standard Assessment Procedure of Part L1A, the emissions due to appliances and cooking are not included in the calculation of the Dwelling Emission Rate. In the pie chart these two sources account for 36% of emissions (28% + 8%). With these emissions excluded, water heating accounts for 34 % of the Dwelling Emission Rate for this typical modern house. [34 = 22 x 100 / (100 36).] A sensibly sized solar hot water system produces about two-thirds of the heat required for hot water over a year. Let s say that after taking account of the electricity used by its pump, the system saves 60% of the emissions for hot water. So a solar hot water system reduces the Dwelling Emission Rate for the pie chart s typical house by about 20%. (20 = 34 x 0.6.) From a table in my April article, we can see that this reduction is worth a couple of credits in the Dwelling Emission Rate issue. We also gain a couple of credits in the Low and Zero Carbon Technologies issue. A further motivation for installing a solar hot water system is likely to be the ongoing monetary rewards from the Renewable Heat Incentive, which is due to come into effect for domestic systems in the autumn of (Before then, RHI Premium Payments will be available for installing renewable heat systems. It is being suggested that payments to eligible recipients will vary between 300 for a Solar Hot Water system to 1,250 for a Ground Source Heat Pump.) GETTING TO CODE LEVEL 3 THE EASY WAY 4 AUGUST 2011.

5 Another credit can be gained fairly easily in the External lighting issue by fitting energy efficient space lighting for your garden. Altogether, in Category 1 we can gain an extra 5 credits, which convert to 5.85 extra points. Category 2 Water Previously, to gain an easy credit for Indoor water use we have assumed a calculated water use not greater than 120 litres/day per person. (The national average for actual water consumption is about 150 litres/day per person). For Code Level 3, the calculated consumption of mains water has to be below 105 litres/day per person. This can usually be achieved by fitting a low volume bath, and water efficient WC s, taps, and showers. Likewise, the washing machine and any dishwasher must be water efficient. Two extra credits are gained. Another two credits results from reducing the calculated consumption of mains water further, to below 80 litres/day per person. This can be achieved by installing a rainwater harvesting system which also benefits the Surface Water Run-off issue, and substantially reduces future water and sewerage bills. The 4 extra credits convert into 6 extra points. Category 8 Management Let s say that you pay the fee (eg, 240) for the Considerate Constructors Scheme, you do your best, and you go significantly beyond best practice. After all, as a selfbuilder you will wish to keep on good terms with the neighbours-to-be. You gain 2 extra credits, which convert into 2.22 extra points. Summary Category Extra points 1: Energy and CO 2 emissions : Water 6 8: Management 2.22 TOTAL Extra points that enable Code Level 3 to be achieved Add the extra points to our 45.7 easy points and we have 60.7 points altogether surpassing the 57 points required for Code Level 3. Of course, all the point scoring above is only for purposes of illustration. In a real situation you would garner the required points wherever suited you. In particular, improving the Dwelling Emission Rate with better insulation and airtightness not only brings more points, it also brings lasting benefits, both to the environment, in the form of fewer emissions, and to you, in the form of lower fuel bills. Next month: Last thoughts about the Code. GETTING TO CODE LEVEL 3 THE EASY WAY 5 AUGUST 2011.

6 FOOTNOTE: Primary Energy As I mentioned last month, one of the Passivhaus standards is that a house uses no more than 120 kwh/m 2 of primary energy per year (where m 2 refers to floor area). Because of lack of space last month, I ve had to carry over the explanation of primary energy. Primary energy is the energy as found in a natural source of energy, in particular in underground fossil fuels, such as oil, coal, and natural gas. These get extracted from the ground, transported, and then transformed into sources of secondary energy, such as electricity or petrol. Energy has to be spent in achieving this transformation. Let s consider turning natural gas into mains electricity. Some energy will have been used in getting the gas from the underground gas field to a modern power station. In the UK, a gas fired power station is about 40% efficient, at best. Most of the energy released by the burning of the gas is wasted in the cooling towers. (In some countries the waste heat is used in district heating systems.) Further losses, about 7% of the power generated, occur in the transmission of the electricity from the power station to the home. The amount of primary energy required to deliver 1 kwh of electricity to a home depends on: The mix of technologies being used to generate the electricity (power stations powered by gas, coal, biomass or radioactivity, wind turbines, etc). The very different amounts of primary energy required for each of those technologies. Many complex calculations and many arbitrary assumptions are involved. Fortunately, we don t have to do the sums. The Passivhaus Institute says that 2.7 kwh of primary energy is used to deliver 1 kwh of grid electricity to a home. Likewise, 1.1 kwh of primary energy is used to deliver 1 kwh of gas energy. In an all-electric house, the Passivhaus limit of 120 kwh/m 2 per year of primary energy is equivalent to 44.4 kwh/m 2 per year at the domestic electricity meter. (44.4 = ) A solar hot water system makes a significant reduction in the primary energy required. The energy contribution from a PV system is less significant because, in practice, much of the PV electricity is exported to the grid, and the Passivhaus methodology takes no account of this. FURTHER INFO: NHBC Free downloads: Zero Carbon Homes an introductory guide for housebuilders (32 pages); The Code for Sustainable Homes Simply Explained (92 pages). Energy Saving Trust Free downloads for their Guidance on meeting the energy requirements: Code for Sustainable Homes level 3; Code for Sustainable Homes level 4; Code for Sustainable Homes levels 5&6. GETTING TO CODE LEVEL 3 THE EASY WAY 6 AUGUST 2011.

7 Communities and Local Government Free download of official guidance: The Code for Sustainable Homes: Setting the standard in sustainability for new homes (68 pages). Ecological Building Society The higher the Code Level (3 or above), the lower their mortgage rate. Copyright article by Robert Matthews in SelfBuild & Design magazine, August, Words: GETTING TO CODE LEVEL 3 THE EASY WAY 7 AUGUST 2011.