Both BIPV (Building-Integrated Photovoltaics — solar tiles or slates) and in-roof panel arrays sit flush with the surrounding roof covering. From a Future Homes Standard compliance perspective they are equivalent — both count toward the 40% PV requirement. From a cost, aesthetic, planning and performance perspective they differ materially. This page compares the two for UK new-build housing in 2026.
BIPV
Individual photovoltaic tiles or slates that replace conventional roofing materials on a 1-for-1 basis. The roof appears unbroken; PV cells are integrated into each tile.
- ✓Visually indistinguishable from non-PV roof at 50m+
- ✓Acceptable in Conservation Areas and Article 4 zones
- ✓Premium aesthetic for high-value custom builds
- ✗~2x cost of in-roof panels per installed kWp
- ✗8-12% lower annual generation per kWp
In-roof panels
Standard photovoltaic panels installed in a flush-mounted tray that integrates with the surrounding tile or slate roof covering. Lowest visual profile of any panel-array installation.
- ✓Half the installed cost of BIPV
- ✓8-12% higher annual generation
- ✓Default for volume housebuilder programmes
- ✗Visible as solar from street elevation
- ✗May require planning permission in Conservation Areas
Cost comparison on a 5 kWp installation
| Cost line | BIPV (slate) | In-roof panels |
|---|---|---|
| PV product (5 kWp) | £9,800 | £2,000 (12 × 425W) |
| Inverter | £820 | £820 |
| Mounting / weatherproofing | £0 (integrated) | £580 (tray + flashing) |
| Installation labour | £1,580 (slate-laying) | £720 |
| Cabling, monitoring, MCS | £820 | £550 |
| Sub-total | £13,020 | £4,670 |
| Offset: conventional slate not needed | −£2,200 | −£420 |
| Net cost on new build | £10,820 | £4,250 |
Net BIPV premium on a 5 kWp installation: approximately £6,570. On a self-build budget of £500k-£1m, BIPV represents 1-1.3% of total build cost — small enough that aesthetic preference often wins. On a volume developer plot (typical £350k-£500k sale price), the same £6,570 premium represents 1.5-2% of plot revenue — material enough that BIPV is reserved for premium plots only.
Annual generation comparison
BIPV produces less electricity per installed kWp than equivalent panel arrays for two reasons: lower module-area efficiency (PV cells surrounded by non-active perimeter) and reduced rear ventilation (BIPV tiles sit directly on the roof structure, panel arrays have a ventilation gap).
| System type | Installed kWp | Annual kWh | Specific yield |
|---|---|---|---|
| In-roof panel (REC Alpha 425W) | 5.10 kWp | 5,150 kWh | 1,010 kWh/kWp |
| Marley SolarTile | 5.10 kWp | 4,690 kWh | 920 kWh/kWp |
| GB-Sol PV Slate | 5.16 kWp (178 slates) | 4,520 kWh | 875 kWh/kWp |
| Tesla Solar Roof | 5.20 kWp | 4,840 kWh | 930 kWh/kWp |
All figures for south-facing 35° pitch in South Midlands (Loughborough reference). The 8-12% generation gap costs approximately £100-£130/yr in self-consumed value at 2026 tariffs — meaningful over 25 years (~£3,000) but rarely decisive against the capital cost difference.
Planning permission and Conservation Areas
For new builds in unrestricted areas, both BIPV and in-roof panels are typically consented within the dwelling\'s primary planning consent — no separate solar PV planning application required. The picture changes in heritage-sensitive contexts:
- Conservation Areas: Panel arrays (in-roof or on-roof) may be conditioned to rear-facing roofs only. BIPV is usually acceptable on any roof orientation.
- Article 4 directions: Permitted development for solar PV is removed. Both BIPV and panel installations require planning consent; BIPV more likely to be approved.
- Listed-curtilage plots: Listed Building Consent required for any external alteration. BIPV solar slate matching heritage materials is usually acceptable; panel arrays usually are not.
- Areas of Outstanding Natural Beauty: Generally treated similarly to Conservation Areas — BIPV preferred but panel installations may be conditioned to non-visible roof areas.
See our Cotswolds Conservation Area case study for a worked example of BIPV slate securing PD approval where panel arrays would have been refused.
Our recommendation
For new builds outside heritage-sensitive areas we specify in-roof panels by default — better economics, higher generation, same FHS compliance. For Conservation Areas, Article 4 zones, AONBs and listed-curtilage replacement dwellings we specify BIPV solar tile or slate — usually the only planning-compliant option. For premium custom builds where the architect specifies BIPV on aesthetic grounds, the BIPV premium is small relative to the build budget and usually worth funding.