Solar panels are moving from an optional extra to a standard part of a new home in England, so a London self build should plan for them now even if the panels themselves come later. The jobs that matter at design stage are a clear roof slope, a proper home for the inverter and battery, and cable routes run before the walls are boarded. On a tight urban plot those decisions are harder to change once the roof is on, which is why they belong on the first set of drawings.
This guide is for people building their own house in London, whether that is a new home on an infill plot, a replacement dwelling on a suburban street or a contemporary house behind an existing terrace. It covers the new rules, what a small or shaded roof means for the design, where the equipment goes and what your electrician should run at first fix.
What the new rules say about solar panels
The Building Regulations for England have been amended to bring in the Future Homes Standard. The explanatory memorandum to the Building Regulations etc. (Amendment) (England) Regulations 2026 explains that new dwellings will need a system for renewable electricity generation on the building or within its curtilage, capable of a reasonable output, with rooftop solar expected in most cases. There are exemptions, for example where a reasonable output cannot be achieved on the roof.
The change comes with transitional arrangements tied to when plans are submitted and when work starts, so whether your own build is caught depends on its dates. Your building control body will confirm which version of the rules applies. Either way, a house built now will be lived in for decades, and designing for solar panels from the start is far cheaper than adding them to a finished roof.
Making the most of a London roof
London plots rarely give you a big, unshaded south facing slope. The roof usually has to work harder, so these points need settling with your architect early:
- Keep one slope clear. Put roof lights, soil vent pipes and extract terminals on the slope that will not carry panels.
- Look at the shade. Neighbouring houses, a party wall upstand or a street tree can shade part of the roof for much of the day. A designer can model that before the roof is built.
- Flat roofs are useful. A flat roof over a rear extension or the main house can take panels on low frames, often out of sight from the street.
- Think about the look. In roof panels, set in place of tiles, sit flush and can suit a design led house better than panels on rails.
Where the inverter and battery go
The inverter converts the power from the panels for use in the house, and a battery stores the surplus for the evening. Both need a cool, dry, ventilated position with room to work on them, close to the consumer unit. In a London house that might be a utility room, a plant cupboard beside the hot water cylinder, a basement plant room or an integral garage.
Space is tight on most urban self builds, so mark the equipment on the drawings and protect that wall from being taken for storage. A loft is usually the wrong place: it is hot in summer, awkward to reach and not where you want a heavy battery.
The cables to run at first fix
| Cable or route | What it does |
|---|---|
| Route from the roof to the inverter position | Brings the solar cables down inside the building rather than in trunking on the elevation |
| Supply cable from the inverter to the consumer unit | Connects the system to the house on its own protected circuit |
| Spare ways in the consumer unit | Leaves room for the solar and battery protection |
| Cat6 from the rack to the inverter and battery | Gives a reliable network link for monitoring and updates |
| Draw cords in every conduit | Lets the final cables be pulled through without opening walls |
A new circuit in a home is notifiable work under Part P, so the electrical installation must be done by a registered competent person or signed off by building control, and the installer will notify the local network operator about the solar system. Our first fix wiring guide for London self builds covers the rest of the cabling plan and the rack those Cat6 runs return to.
Solar, the heat pump and the car
A new London home built to the latest standards is likely to have a heat pump, an EV charge point and possibly a battery, all drawing on or storing the same power. Solar panels pay back best when the house uses what they generate, so the systems should work together: hot water heated while the sun is out, the car charged when the battery is full, and the evening covered from storage.
That is what a well planned smart home does. Our home automation in London page shows how energy, heating and lighting come together on one app, and our EV charger wiring guide for London self builds covers the charge point side.
How we help
We design, supply, install and programme the smart home, and we give your electrician drawings and cable schedules so the solar routes, the rack and every other cable are in the right place at first fix. Our founder, Kieran McGuire, is an electrician, so the electrical side is considered from the first drawing. Our survey and design service explains how it works, and a design consultation is £360 plus VAT, with extra time at £90 an hour plus VAT.
Questions we are often asked
Do I have to fit solar panels on my London self build?
It depends on when your build is submitted and started, because the new requirement comes in with transitional arrangements. Your building control body will confirm which rules apply to you.
My roof is small and shaded. Is solar still worth it?
Often yes, especially with a flat roof over an extension or careful layout around roof lights. A shading check at design stage tells you what to expect before you commit.
Is a battery worth adding?
It suits households who are out during the day and want to use their solar in the evening. If the budget is tight, plan the space and cable now and add the battery later.
Will solar panels work in a power cut?
Most grid connected systems switch off when the grid fails, for safety. Some battery systems can supply chosen circuits in an outage, but only if they are designed and wired that way.
Can I see what the panels are generating?
Yes. Inverters and batteries come with monitoring, and a wired network link keeps it reliable. A smart home can show it on the same screen as the heating and lighting.
Book a consultation or call our head office on 01344 937999 (London office 0208 064 0196).
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