Building Integrated Photovoltaics (BIPV): A Design Guide for Architects

Building integrated photovoltaics (BIPV) are solar modules that replace part of the building envelope, such as roof tiles, facade cladding, glazing or sunshades, instead of being bolted on top of it. The module keeps out weather, controls light and generates electricity at the same time, so it has to pass building product rules as well as electrical ones.

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Most solar projects on buildings still follow the same sequence: the architect designs a roof, the roofer finishes it, and a solar installer arrives later with rails and clamps. Building integrated photovoltaics reverse that order. The photovoltaic layer is drawn into the facade grid or roof build-up from the first sketches, and the decision about module size, colour and transparency becomes a design decision rather than a procurement afterthought. This guide covers how BIPV differs from conventional rooftop solar, the four main product families, the standards that apply, what real buildings have achieved, and where projects usually go wrong.

What Is BIPV and How Does It Differ From Rooftop Solar?

BIPV is a photovoltaic product that does the job of a building component. The IEA PVPS Task 15 research programme, which coordinates international BIPV research, defines it as the integration of solar panels directly into building elements or components, such as windows, roof tiles or facade cladding systems. Fraunhofer ISE puts the test in practical terms: the BIPV element replaces other components, including their function, and acts as a roof tile or part of a glass facade.

The opposite case is building-applied photovoltaics (BAPV). Here a standard module sits on rails above a roof or wall that is already complete. If you unscrew a BAPV array, the building is still watertight. If you remove a BIPV module, the building loses a piece of its roof, wall, window or shading. That single difference drives almost everything else: who is liable, which tests apply, how the product is warranted and when it has to be specified.

For architects the practical consequence is timing. A BAPV array can be added at the end of a project or years after completion. A BIPV facade has to be resolved at the same stage as the cladding system, the curtain wall or the glazing schedule, because it is one of them.

Why the extra effort can pay off

The argument for integration is not that BIPV produces more electricity per square metre than a rooftop array. It usually does not, because facades are vertical and many integrated products trade some output for colour or transparency. The argument is that the module displaces a material you were going to pay for anyway, and that it opens up surfaces a conventional array cannot use. On a tall building the roof is small compared with the floor area it has to serve, while the facades are large, which is why vertical BIPV matters most in dense cities. Our article on sustainable facades for high-rise buildings looks at that problem from the envelope side.

Types of Building Integrated Photovoltaics

BIPV products are easiest to understand by the building element they replace. The same cell technology can end up in very different products depending on whether it has to shed rain, carry wind load, let daylight through or block summer sun.

Roof integration

Roof products replace the weather layer itself. They range from solar tiles and slates that sit in the same pattern as conventional tiles, to in-roof modules that form a continuous watertight plane, to glass skylights and atrium roofs with cells laminated between the panes. Roofs still offer the best orientation and tilt in most climates, so roof integration usually gives the highest yield per square metre of any BIPV family. The comparison with green roofs is a real design choice on flat roofs, and our piece on green roofing versus solar roofs sets out the trade-offs.

Facade cladding

Opaque PV cladding replaces stone, metal, fibre cement or ceramic panels in a ventilated rainscreen, or replaces spandrel panels in a curtain wall. Because the cells are hidden behind coloured or textured glass, these products give architects the widest control over appearance. Fraunhofer ISE has developed coloured modules under the name MorphoColor for exactly this purpose, opening a range of design options for planning offices. If your project uses a unitised or stick system, our explainer on curtain wall types and construction covers the frame logic that a PV spandrel has to fit into.

Semi-transparent glazing

PV glazing laminates cells inside insulated or laminated glass, spaced so that part of the light passes through. The spacing becomes a pattern on the facade and a shadow pattern inside, so it has to be designed together with daylighting and views. Thin-film products give a more even tint, while spaced crystalline cells give a stronger graphic effect.

Shading devices

Louvres, fins, canopies, brise-soleil and balcony balustrades can carry PV as well. Shading is often the easiest entry point for a first BIPV project, because the element sits outside the thermal line and does not have to keep out rain or air. A fixed or moving PV louvre also solves two problems at once: it cuts solar gain on glazed facades and turns that blocked sunlight into electricity. Our article on dynamic facades shows how movable shading systems are designed.

BIPV types compared

The table below summarises what each family replaces and the main design question it raises.

Standards and Certification for BIPV

The hardest part of BIPV is rarely the solar technology. It is the fact that one product has to satisfy two rulebooks. According to the BIPV quality and normative framework published on Solarchitecture, the Swiss BIPV platform run with SUPSI, the building and electrical functions still sit in separate legal acts in Europe: the Construction Products Regulation (CPR 305/2011) and the Low Voltage Directive (LVD 2014/35/EU).

In December 2024 IEA PVPS Task 15 published a report titled Advancing BIPV Standardization, edited by Fabio Parolini and Pierluigi Bonomo of SUPSI. It identifies the current requirement for double certification, with the associated costs, time and uncertainty, as one of the main barriers, and proposes performance-based tests for electrical safety, mechanical safety and structural integrity, including a wind-driven rain test.

The US Department of Energy reached a similar conclusion. Its summary of a request for information on BIPV, published on 7 March 2022, notes that the certification process was developed for standard sizes and a unique mounting system, so every custom size would need to be tested and certified before it could be legally installed. The same document records that BIPV is perceived as more expensive than rooftop PV, which keeps demand low and manufacturing investment low.

How to Design With Building Integrated Photovoltaics

Good BIPV design starts with the same questions as any envelope design, then adds electrical ones. The order matters, because the electrical layout follows the architecture, not the other way round.

Orientation and self-shading

Map which surfaces receive useful sun across the year before deciding where active panels go. South-facing roofs in the northern hemisphere perform best, east and west facades produce morning and afternoon peaks, and north facades usually do not justify active modules. Neighbouring buildings, balconies, fins and your own massing can shade the lower floors for most of the day. Treat shaded zones as places for matching passive panels rather than forcing cells into them.

Heat behind the module

Crystalline cells lose output as they get hotter, so the way a panel is backed matters. A ventilated rainscreen with an air gap behind the PV layer keeps cells cooler than a panel bonded to an insulated wall. This is one reason ventilated facades and BIPV cladding work well together, and it connects directly to the low-energy strategies in our passive design architecture guide.

Colour, texture and output

Coloured front glass, printed patterns and textured surfaces hide the cells but block part of the light that reaches them. The darker and more neutral the finish, the smaller the penalty; bright or pale colours cost more output. Ask suppliers for the rated power of the exact finish you specify, not the datasheet value of the standard black module.

Cables, inverters and maintenance

Every active panel needs a cable route, a junction box location that can be reached, and a way back to an inverter. On a rainscreen facade the cable runs in the ventilated cavity; in a curtain wall it has to pass through mullions or transoms designed for it. Plan access for replacing a single panel without dismantling its neighbours, and agree early who maintains the facade and who maintains the electrical system, since the DOE summary notes that many electrical engineering firms do not design solar systems and extra contractors add complexity.

Real BIPV Projects Worth Studying

Built examples show what the technology can do when it is part of the architectural idea from the start.

Copenhagen International School Nordhavn

The Copenhagen International School Nordhavn by C.F. Møller, completed in 2017, is wrapped in 12,000 solar panels, each individually angled to create what the architects describe as a sequin-like effect. The cells cover 6,048 square metres and are expected to supply more than half of the school’s annual electricity consumption. C.F. Møller describes it as one of the largest building-integrated solar power plants in Denmark. The panels were developed with SolarLab, and the project received a special recognition award for building integrated solar technology in 2017.

What makes the school a useful precedent is that the solar skin is not hidden. The blue-green panels are the identity of a 26,000 square metre building for 1,200 students on the Nordhavn waterfront, and the varied angles turn a uniform module into a facade that changes with light and weather.

EDF building in Dijon

The Électricité de France building in Dijon shows the glazing approach at scale. Its outer screens are made of photovoltaic glass in which cells are spaced in a pixel pattern, so the facade produces electricity while staying partly transparent. Projects like this one show that semi-transparent PV can be the dominant architectural material of a building rather than a technical accessory.

FAQ

Is BIPV more expensive than rooftop solar?

Per watt, usually yes. The US Department of Energy’s 2022 summary notes that BIPV is perceived as more expensive than traditional rooftop PV. The fairer comparison subtracts the cladding, roofing or glass the BIPV product replaces, because that material would have been bought anyway.

Do BIPV facades produce as much as roof panels?

No. Vertical surfaces receive less annual sunlight than well-tilted roofs, and coloured or semi-transparent finishes reduce output further. Facades make sense where roof area is small relative to floor area, which is the typical case for multi-storey buildings.

Which standards apply to building integrated photovoltaics?

In Europe, BIPV products fall under both the Construction Products Regulation and the Low Voltage Directive. EN 50583 covers photovoltaics in buildings and IEC 63092 is its international counterpart, alongside module qualification under IEC 61215.

Can BIPV be added to an existing building?

Yes, when a facade or roof is being replaced anyway. A recladding or reroofing project is the natural moment, because the BIPV element takes the place of the new cladding rather than adding a layer on top.

Technical specifications should be verified by a licensed professional for your specific project, and certification requirements vary by jurisdiction.

What This Means for Your Next Project

Your Next Step: On your next facade or roof package, ask two BIPV suppliers for their standard module sizes and certified colour range before the facade grid is fixed, then test whether your facade rhythm can be built from those sizes alone.