Most solar guides skip the downsides because they're trying to sell you solar. This stage exists to give you a fair view before you spend money on quotes. None of these are deal-breakers on their own; together they're the stuff you should think about.
Property value
The honest answer: UK research is mixed, but the dominant finding is that solar has a small positive or neutral effect on property value when it's owned outright (not leased). The benefit is bigger on newer properties and in areas where energy efficiency is a buyer concern. The benefit is smaller in areas where buyers prefer character / heritage looks.
- Owned solar generally helps the EPC rating, which most buyers check on Rightmove.
- Leased solar (where you don't own the panels but the leasing company has rights to your roof) is a known mortgage problem. Avoid leasing arrangements.
- Don't install solar expecting a property-value uplift to be the financial case. The case is operational savings; the value angle is a small bonus at best.
What it actually looks like
The visual impact depends on your roof and your panels. Black-on-black panels on a dark roof look almost invisible at distance; framed silver panels on a red-tile roof are very visible. Front-facing installations are more visible than rear-facing.
A photo gallery of real installs is the most useful way to think about this. Below are examples by property type as they come in.
The honest version of “how it looks” depends on:
- Panel colour: all-black is the current premium look; framed silver is cheaper but more visible.
- Roof contrast: dark roof + black panels = barely visible. Light roof + framed panels = highly visible.
- Position: rear-facing (away from the street) is much less impactful than front-facing.
- Layout: a clean rectangular array looks intentional. Mixed orientations or panels around obstructions can look messy.
Install disruption
For a typical 4kWp residential install:
- Scaffolding goes up 1-3 days before install and stays until inspected (usually 1-3 days after).
- Install itself is 1-2 days of trades on-site (1-2 roofers, 1 electrician).
- Inside the house: you need an inverter location (usually loft or utility room) and, if you have a battery, additional cabinet space — typically a 60×60×20cm wall-mounted box or a 100×60×20cm floor unit.
- Electrical work may involve a brief power cut (1-2 hours) while the system is wired into your consumer unit.
- Aftermath: DNO notification and certification takes 4-8 weeks. You can use the system before then but it's not officially commissioned.
Planning and consents
Most domestic solar installations fall under permitted development rights— no planning permission needed. The main exceptions:
- Listed buildings need Listed Building Consent, which is often refused.
- Conservation areas restrict front-facing or street-visible panels.
- Flat roofs have specific rules around panel projection above the roof line.
Your installer should advise on this and submit any required applications. Don't take “we'll just install it” on faith — if you're in a conservation area, ask them in writing what permissions they're getting.
20-year commitment, maintenance, and warranty
A solar system is a 20-25 year investment. Warranties give you protection but not zero-effort ownership:
- Panel warranties are typically 12-25 years on product + 25-30 years on performance.
- Inverter warranties are typically 5-12 years. Inverters are the most likely component to fail and need replacement.
- Battery warranties are typically 10 years and may include a degradation guarantee (e.g. ≥70% capacity at end of warranty).
- Workmanship warranty from the installer is typically 2-10 years — the longer the better. Check this matches the panel warranty.
- Annual checks on output via app are normal. A professional clean and inspection every 3-5 years is recommended (£100-300).
When solar doesn't make sense
To be straight: there are cases where solar isn't a good investment. Stage 1 caught some of these. Others worth considering:
- You're planning to move within 3-5 years and your area doesn't value solar in property prices.
- Your annual electricity bill is under £600 — at low consumption, the system rarely pays back within its life.
- Your roof needs replacement in the next 5 years — you'd pay to remove and reinstall the system.
- You can't get a price for installation under £2,000/kWp installed in your area — at higher rates the maths gets very tight.