r/SustainableHomeUK

I wanted to see how the sun's path actually hit my building and get a visual understanding of how surrounding buildings changed the light throughout the day. I searched for a "UK Building Shadow Simulator" but couldn't find one, so I built one. It turned out to be far more useful than I expected.

This can be used for planning solar panels, deciding where to place a greenhouse or vegetable beds, finding the sunniest spot for a patio or balcony, understanding how much daylight reaches your home, or simply seeing how the seasons change the shadows around your property. I'd genuinely appreciate some honest feedback

what other practical uses can you think of, and what features would make it even more useful?

Hey all,

I'm interested in reducing my energy expenditure and going somewhat "off-grid" for want of a better term. I'm not sure how realistic it is, as we're quite low income, so I would need to really order and prioritise everything by cost efficiency.

I live in a 3 story town house. It's only 20 years old and I think quite well insulated already, with an EPC of B. We have a share in this property and also have a landlord who we pay rent to.

I have recently got an EV on lease, but currently don't have a charger at home, so I would assume this is going to be my first port of call. The EV has a very large battery and is ready for V2G/V2H etc. but don't think it's a model that is currently able to do this in the UK, although if I were to get a charger, I would hope to be able to at least future proof it so that when and if it does become available, it will be easy to just swap out the charger.

Another thing is our house gets insanely hot, especially on the top floor. I'm so confused with all the different types of heat pump, but it seems mad that I can't just harvest the heat from inside the property, to heat the water and also cool the house, but I might just be misunderstanding something. We have passive ventilation in the house, but it doesn't do a good job of releasing the heat.

Solar is a possibility, we have a roof facing south east, but I don't think it would get an awful lot of PV on top of it and with it being 3 story I'd be worried about the cost of scaffolding etc. as well.

Really I'm looking for some inspiration and advice. I don't really know where to start! Is there an optimal order to do things in?

One of the most overlooked sustainable-home checks is whether kitchen and bathroom extractor fans are actually working effectively rather than simply making noise. Current UK guidance treats ventilation as a core part of preventing condensation, damp and mould, and a stronger approach is to keep trickle vents open, use extractor fans during moisture-producing activities, and clean the fans regularly so airflow is not reduced by dust and grease build-up. That makes fan maintenance a practical efficiency habit, not just a cleaning task, because a home that traps moisture can become less healthy and harder to manage even if the heating is working well. For many households, keeping ventilation working properly is a smarter first step than buying extra moisture gadgets or heavily fragranced products to cover the symptoms.

One of the most useful sustainable-home habits is understanding that turning the thermostat far above the target temperature does not heat the home faster, it only tells the system to keep running until that higher temperature is reached. The stronger approach is to set the room thermostat to the lowest comfortable level, usually somewhere around 18°C to 21°C, then use heating controls properly so warmth is delivered where and when it is actually needed. That makes correct settings more important than aggressive settings, because overheating rooms wastes energy, raises bills and often reduces comfort rather than improving it. For many households, the smarter first upgrade is not replacing the whole heating system, but using the existing controls with more precision.

One of the most overlooked sustainable-home checks is whether a hot water cylinder is actually set to the right temperature. The strongest approach is not to turn every control down as low as possible, but to make sure the cylinder thermostat is set high enough to store water safely without overheating it unnecessarily. In many UK homes, that makes correct hot water control a smarter first step than chasing bigger upgrades, because poor settings can waste energy at one extreme or create safety and hygiene problems at the other. For households trying to cut bills and run the home more efficiently, the sustainable option is usually correct control, not simply lower control.

One of the most practical low-cost sustainable upgrades in a UK home is to treat the front door as a heat-loss point rather than focusing only on the loft or boiler. A stronger approach is to check the keyhole, letterbox, bottom gap and edges of the door, then seal those areas with purpose-made covers, flaps or brush strips so cold air is reduced without affecting normal use. The important rule is to stop uncontrolled draughts without blocking planned ventilation elsewhere in the home, because a warmer home still needs healthy airflow. For many households, this makes front-door draught proofing one of the quickest first-step improvements before moving on to larger insulation work.

One of the most practical sustainable-home checks in the UK is whether an off-peak tariff actually matches the way electricity is used. Ofgem says Economy 7 gives seven cheaper off-peak hours, usually overnight, but it can still leave households worse off if they do not shift enough electricity use into that cheaper window. The strongest approach is to treat the tariff as part of a routine change rather than a billing trick: storage heaters, hot water heating, EV charging, dishwashers and washing machines need to be timed properly, and the home also needs the right meter to record peak and off-peak use separately. For many households, that makes tariff choice a lifestyle-and-equipment decision, not just a price comparison, because the wrong tariff can reward the supplier more than the household.