Self-build renewables designed in from day one

Why self-build needs early renewables input

New build projects are unforgiving about decisions made at the wrong stage. Roof pitch and orientation set solar output for the life of the building. Riser routing locks in heat pump pipe runs. First-fix electrical layout determines whether batteries and EV chargers are viable. Get these decisions wrong at RIBA Stage 2 and you will pay for them for 50 years.

We work with Cornwall self-builders, architects and main contractors from concept design onwards. Our input into your solar, battery, heat pump, EV charger and underfloor heating decisions feeds directly into architect drawings and M&E layouts, well before any orders are placed.

Part L 2022 and the Future Homes Standard

Part L 2022 delivers an approximately 31% reduction in CO2 emissions over Part L 2013. The two most common routes to compliance are:

• Solar PV + gas boiler — historically common, increasingly uneconomic for new builds because the gas boiler still has to go somewhere in the site scoring.
• Solar PV + air source heat pump — now the default for Cornwall new builds. Heat pumps deliver the CO2 reductions cleanly, and the combined spec comfortably meets Part L and sets you up for the upcoming Future Homes Standard.

The Future Homes Standard (expected 2025 onwards) effectively mandates low-carbon heating. Building a gas boiler into a Cornwall self-build today is like building a fireplace into a house in 1995 — you can, but it is already legacy.

The decisions we help with

• Roof orientation and pitch — south-facing 30–40 degree pitches produce the most, but east/west splits are often fine if specified early.
• Integrated vs on-roof solar — integrated looks better on a new build but costs more and has a smaller product range. We'll walk you through the tradeoffs.
• Heat pump siting — external unit location, noise boundary calc, pipe runs to the buffer tank.
• Underfloor heating loop design — low flow temperature optimisation for heat pump operation.
• First-fix for future EV and battery — consumer unit sizing, cable routes, plant room spec.
• Grid connection capacity — coordinating G99 solar export alongside your new-build DNO application.

0% VAT and the DIY Housebuilder reclaim

Self-builds benefit from two overlapping VAT advantages. The 0% energy-saving materials VAT applies to solar, battery, heat pump and insulation work — meaning the supply of those materials and installation labour is zero-rated rather than 20%. Separately, the DIY Housebuilder scheme lets you reclaim VAT on eligible building materials at project completion. Our invoicing is structured to be compatible with both schemes. Keep every invoice carefully — HMRC is strict on self-build VAT reclaim paperwork.

Typical Cornwall self-build spec we install

A 4-bed self-build on a 1500-2500 sq ft plot typically gets:

• 8-12kWp solar PV on south-facing roof
• 13-20kWh battery storage (Foxstar, GivEnergy or Sigenergy)
• 8-12kW ASHP with 300L unvented cylinder and 50L buffer tank
• Wet underfloor heating ground floor, rads upstairs
• 22kW 3-phase EV charger first-fix (or 7kW single-phase installed at completion)
• Solar diverter to immersion for summer surplus

System cost depends on specification and site complexity. Typical range: £28,000 to £48,000 for the combined renewables package.

Next steps

We run a free design consultation for any Cornwall self-build project, including architects and main contractors operating on behalf of clients. Contact us or call 01209 596 002 to book a consultation.