[{"data":1,"prerenderedAt":121},["ShallowReactive",2],{"resource-/resources/your-home-is-not-the-average-home":3},{"id":4,"title":5,"audience":6,"author":6,"body":7,"category":104,"date":105,"description":106,"draft":107,"extension":108,"image":6,"imageAlt":6,"meta":109,"navigation":110,"ogImage":17,"path":111,"pdfPath":6,"resourceType":6,"seo":112,"series":6,"stem":113,"tags":114,"visibility":119,"__hash__":120},"resources/resources/your-home-is-not-the-average-home.md","Your Home Is Not the Average Home",null,{"type":8,"value":9,"toc":94},"minimark",[10,18,30,33,38,41,44,50,54,57,61,64,68,71,74,78],[11,12,13],"p",{},[14,15],"img",{"alt":16,"src":17},"Distribution of modelled annual heating hours across 107,336 Nottingham homes: a two-humped spread from 557 to 5,868 hours, with the 3,592-hour average marked on the shoulder of the first cluster, the most common homes clustered near 4,900 hours, and the old 1,800-hour assumption far to the left.","/images/resources/articles/distribution-hero-1600x900.png",[11,19,20],{},[21,22,23,24,29],"em",{},"This curve is live. ",[25,26,28],"a",{"href":27},"/views/distribution","Open the distribution view"," to\nmove the marker and read where any home on it sits.",[11,31,32],{},"Almost everything you are told about your home's energy comes as a\nsingle number. The certificate gives it a band. The heat pump quote\ngives it a running cost. The retrofit estimate gives it a saving.\nEach of those turns your home's details, plus a set of standard\nassumptions, into one figure. They are useful for comparing homes\nquickly, and they are not the same thing as what your own house will\ndo. Your bill, when it lands, is the gap between the single figure\nand the particular house, and that gap has a shape worth seeing.",[34,35,37],"h2",{"id":36},"one-number-or-a-distribution","One number, or a distribution",[11,39,40],{},"Here is the idea made concrete. When we built a small pipework\ncalculator, we assumed a home's heating runs about 1,800 hours a\nyear, the sort of single figure that sits inside a calculation and\nyields a tidy answer. Then we simulated 107,336 homes through the\ngovernment's national calculation method, hour by hour, and asked\neach one how long its heating was modelled to run. The median is not 1,800. It is close to\n3,600. One home in ten is modelled to run past 5,175 hours, one in\nten under 2,474, and across the whole set the curve stretches from a\nfew hundred hours to nearly six thousand. The chart above is that\nspread, and the 1,800 mark sits far to the left of almost all of it.",[11,42,43],{},"The point is not only that the round number is low, though for the\nmedian home it is. It is that a single number cannot stand in for\nthe curve. There is a wide distribution, and every home is one point\non it. An average drawn across it lands in the middle, where fewer\nhomes actually sit than you might think, and the further your home\nis from that middle the less the average has to say about your bill.",[11,45,46],{},[14,47],{"alt":48,"src":49},"The single average of 3,592 hours shown as one point, joined by a dropline to its thin slice of the full modelled distribution of 107,336 homes below. Most homes sit far from the average.","/images/resources/articles/distribution-onenumber-1600x900.png",[34,51,53],{"id":52},"why-the-same-house-is-not-the-same-house","Why the same house is not the same house",[11,55,56],{},"Two homes that look the same on paper, same age, same size, same\ncertificate band, can sit a long way apart on this curve. A band is\na wide bucket, and inside it the details still differ: the loft that\nwas topped up and the one that was not, a single draughty bay, a\ncorner plot against a sheltered mid terrace. In this simulation\nthose recorded differences are what move a home along the curve.\nReal life adds more on top, because how a home is lived in and how\nwarm it is kept vary from household to household in ways no model\nhere observed. Either way, none of it shows in a band, and all of it\nlands on the bill.",[34,58,60],{"id":59},"what-to-do-with-that","What to do with that",[11,62,63],{},"The averages are not useless. They are how a whole country is sorted\nquickly, and they are fine for that. They are simply the wrong tool\nfor a decision about one home, because the thing they set aside is\nthe thing you are deciding about: where your home sits on the curve.\nBefore spending real money on a heat pump, a refit or insulation,\nthe question worth answering is not what the average home saves. It\nis what yours does, and that can be a very different number.",[34,65,67],{"id":66},"where-this-leaves-you","Where this leaves you",[11,69,70],{},"For a single home, the useful first step is a reading of your own,\nbuilt from what is already recorded about your house rather than an\naverage laid over it. For anyone looking after many homes, the same\ntruth scales into a harder and more valuable question: which of your\nhomes are the outliers, and where. That is a reading our record can\nproduce for any stock in England, home by home, from public records,\nbefore anyone visits.",[72,73],"hr",{},[34,75,77],{"id":76},"about-the-numbers","About the numbers",[79,80,81,85,88,91],"ul",{},[82,83,84],"li",{},"107,336 homes across Nottingham, each simulated through the\nnational calculation method, full year, hourly, from public energy\ncertificates. Active heating hours are the hours a home is modelled\nto be calling for space heat.",[82,86,87],{},"Distribution of modelled active heating hours: minimum 557, 10th\npercentile 2,474, median 3,592, 90th percentile 5,175, maximum\n5,868. The 1,800 hour round number sits below all but about one\nhome in forty.",[82,89,90],{},"The spread illustrates the principle; it is not a claim about any\nsingle home. Weather and occupancy schedules are the method's\nstated conventions, so the spread shown comes from recorded\nproperty characteristics; your own year and how you run your home\nwould move your point further.",[82,92,93],{},"Aggregates only. No figure for any single home leaves the analysis.",{"title":95,"searchDepth":96,"depth":96,"links":97},"",3,[98,100,101,102,103],{"id":36,"depth":99,"text":37},2,{"id":52,"depth":99,"text":53},{"id":59,"depth":99,"text":60},{"id":66,"depth":99,"text":67},{"id":76,"depth":99,"text":77},"articles","2026-08-11","Almost everything you are told about your home's energy comes as a single number: a band, a running cost, a saving. We simulated 107,336 homes through the national calculation method, and their modelled heating year runs from a few hundred hours to nearly six thousand. The average describes the middle of a wide curve, and your home is somewhere on it, not at the average.",false,"md",{},true,"/resources/your-home-is-not-the-average-home",{"title":5,"description":106},"resources/your-home-is-not-the-average-home",[115,116,117,118],"home energy","EPC","national calculation","heat pumps","public","kN1lUwuwBzvxcKyilP37L_nj1-A7DDc535RnABY1FH8",1786620468013]