Heat pumps, solar, air conditioning and insulation on a London home. Every rule below is drawn where it actually applies — then checked against your own borough's planning record.
Permitted development on most London houses, including inside conservation areas — provided the panels sit close to the roof and aren't prominent from the street.
No planning permission, no conservation area issue, no Article 4 problem. It is also the fastest payback of anything on this site — and it lowers the heat pump capacity you need to buy.
This is where permitted development most often stops. On a road-facing slope in a conservation area — and anywhere an Article 4 direction applies — you are likely to need a full application.
The rule that decides most London installations isn't planning policy — it's the metre of clearance to your neighbour's boundary. On a terrace with a filled-in side return, that is often the whole problem.
Worth being straight about: cooling adds to your bill. It buys comfort on the ten to twenty genuinely hot days a year, and most split systems will heat efficiently in winter too.
Costs as ranges, grants as they stand in 2026, and the figure stated plainly even where it argues against doing the work.
£8,000–£15,000 installed, less a £7,500 grant — £9,000 if you're off the gas grid, until March 2027.
Read the guide →Payback of 7–12 years, export income through the Smart Export Guarantee, and how DNO grid approval works.
Read the guide →Loft pays back in 1–2 years. Double glazing takes 20–40. We say plainly which is which.
Read the guide →£1,500–£3,000 for one room. It adds roughly £50–£80 a year to your bill rather than saving it.
Read the guide →Permitted development rights don't apply to flats at all — so the guidance above works differently for you. Balcony solar, communal rooftop systems and battery-only setups are all still open.
Our own compiled index of conservation area coverage and Article 4 planning rules — borough by borough, plus area guides where a neighbourhood differs sharply from its borough. This is the detail that decides whether a solar or heat pump install needs planning permission where you actually live. Compare all boroughs →
Enter your property type, current heating and bill — get an instant estimate across all four technologies.
Open the savings calculator →Plainly: right now, it isn't. This site currently earns nothing. There are no adverts, no sponsored placements, no affiliate links, and no paid listings anywhere on it. Where we point you to an installer, we send you to the official MCS certified installer register — a free public tool we have no relationship with and earn nothing from.
That may change. If we add affiliate links in future — where a partner pays us a fee for referring an enquiry — we'll say so here plainly and label them where they appear. What won't change is the editorial position: no installer will ever be able to pay to be featured, mentioned, or ranked ahead of another, and no commercial arrangement will alter the cost, grant or planning figures on this site.
The guides were researched and written before any of that was on the table. The numbers you see are the numbers, not a pitch.