The Centre for Sustainable Energy (CSE), an independent charity, reviewed four of its household energy advice pages in July 2026: its energy saving myths page, its guide to mechanical ventilation with heat recovery, its Economy 7 page and its park homes guide. Each page carries the line "Reviewed July 2026"1. No changes to the advice itself were announced, and no reason for the review has been reported.
The myths page restates several figures on where a home loses heat. Of the heat lost from a home, CSE says about 35% goes through the walls, about 25% through the roof and only about 10% through the windows, so loft and cavity wall insulation make a bigger difference than double glazing1. It gives a recommended loft insulation depth of 270mm (10.5 inches) and says boxes and furniture stored in a loft do not insulate a home, and can compress insulation that works best when it traps air1. On standby, it says leaving televisions, broadband routers, set-top boxes and games consoles on costs the average household £45 a year according to the Energy Saving Trust, with some appliances costing up to £10 to keep on all year and others just a few pence1.
On heating controls, CSE says a sensible room temperature is between 18-21C, that turning a thermostat up does not heat a house faster, and that turning radiators down saves money only if the thermostat is turned down at the same time1. It says heat pumps need to be on all the time and night storage heaters are set to charge up at night, and that storage heaters are a cheap form of electric heating if the controls are understood, settings are updated to match the heat needed and the household is on the Economy 7 tariff1. Its Economy 7 page says the cheaper off-peak rate is about a third of the price of on-peak electricity, with off-peak hours normally midnight to 7am in winter and 1am to 8am in summer, though this can vary between suppliers3. CSE says Economy 7 is cost effective for households using electricity for heating and hot water that use more than 40% of their electricity at night3.
The ventilation page covers mechanical ventilation with heat recovery (MVHR), a whole-house system that extracts damp air and draws in fresh air. CSE says systems typically have 80 to 90% heat recovery efficiency and are inaudible during normal use, and that households can reduce heating costs by 10 to 30%2. On cost, it says decentralised systems start from £600 per fan, while centralised MVHR starts from around £3,000 and could cost well over £10,000 depending on size and type2. It says MVHR works best in relatively airtight buildings such as new-builds or older properties being fully refurbished, and that retrofitting needs a comprehensive airtightness strategy including a series of airtightness tests2.
The park homes guide says many park homes are vulnerable to temperature fluctuations, damp and noise because of how they were built, and that many have no mains gas, so residents are likely to use oil or LPG boilers4. It says electric storage heaters are only an option for park homes with their own electricity supply, because residents on sub-meters cannot choose their supplier, tariff or payment method4. It says heat pumps are not currently very common in park homes because they work best in insulated homes and many park homes are not insulated at all4. External wall insulation adds 2 to 4 inches to the width of walls, and roof insulation is "definitely not a DIY job"4.
"Cavity wall insulation is much more likely to solve problems of damp caused by condensation because it makes your walls less cold so less prone to damp."
Why it matters for households
The figures set out where heat actually leaves a home, which shapes what a household can control. Walls and roofs account for the bulk of heat loss in CSE's figures, while windows account for about a tenth, so the fabric of a building matters more than glazing for keeping heat in1. For homes off the gas grid, the park homes guidance sets out the limits of what residents can change: sub-metered households cannot choose a supplier or tariff, which constrains any move to a cheaper off-peak arrangement4. For households that can shift demand, Economy 7 offers cheaper night-time electricity but a higher price for the other 17 hours, so its value depends on how much electricity is used overnight3. MVHR addresses ventilation heat loss rather than the fabric, and its savings depend on the building being airtight enough for the system to work2. On local energy supply and energy local clubs, the pages reviewed do not cover community generation or local supply arrangements; the solar guidance notes only that most solar PV systems are connected to the grid and leftover energy can be sold back through the Smart Export Guarantee1. The wider question of a home's energy independence turns on these same levers: how much heat the building loses, when electricity is used and what supply arrangements a household can access.
What happens next
CSE's park homes page says Park Home Warm Home Discount applications usually open in September and must be made each year4. No other dated next steps are given on the reviewed pages.