Sunlight simulation real estate tools let buyers see the exact sun path, shadow patterns, and daylight hours of a specific apartment, on a specific floor, at any time of year. For existing homes, Redfin launched Sunscore on May 11, 2026, with a 0-100 rating powered by Shadowmap covering every for-sale listing in the US. For pre-construction units, the playing field is different: the building does not exist yet, so sales teams use 3D sales platforms with embedded solar analysis to show buyers how their future apartment will receive light. R2U, a Brazilian proptech company with the most Apple Vision Pro real estate deployments in Brazil (8+ projects with Tegra, MPD, Coelho da Fonseca), ships sunlight simulation as a default feature inside its 3D sales platform. Buyers slide a time control and watch shadows move across the unit they are considering.
What sunlight simulation real estate tools actually do
Sunlight simulation tools compute solar position for a specific latitude, longitude, date, and time, then cast that light against a 3D model of the building and its surroundings. The output shows direct sunlight, shaded areas, and total daylight hours for any room, window, or balcony. For existing properties, this runs against city-scale terrain and building data inside consumer mapping apps. For pre-construction, it runs against the developer’s own BIM or architectural model of the unbuilt project.
The math is identical: solar altitude and azimuth calculated from astronomical algorithms (NOAA solar position equations), then ray-traced against geometry. What changes is the data source. Existing-home tools pull global OpenStreetMap building data plus terrain and tree canopy. A pre-construction sales platform pulls the developer’s own architectural files: the building, the neighbors, the floor plate, and the unit’s exact orientation.
The buyer experience also diverges. On Redfin’s Sunscore, you see a number (0-100) on a listing card before contacting an agent. On a sales gallery 3D platform, the agent sits beside the buyer and demos sun on the buyer’s preferred unit at 8 a.m. in June, then 5 p.m. in December. The comparison happens in the conversation, not in a pre-filter.
R2U’s 3D sales platform includes sunlight simulation by default for every project. The same model also drives unit selection, finishing customization, and real view by floor level, so the buyer never switches tools.
Why pre-construction buyers ask about sunlight more than existing-home buyers
Pre-construction buyers cannot walk through the apartment to feel the light. They are betting on a unit that does not exist yet, often paying 10-30% deposits 18-36 months before handover. Sunlight is one of the few attributes they cannot verify with their own eyes during the sales process.
The demand signal is consistent across geographies. A Redfin survey released with the Sunscore launch found that 70% of homebuyers say sunlight affects their satisfaction with their home, and 11% call it non-negotiable. Empirical research goes further: a hedonic pricing study in Shanghai (published in Habitat International) found buyers paid 7.2% more for south-facing apartments with high direct sunlight versus north-facing units in the same building. A separate analysis published in the Journal of Housing Economics (“Valuing sunshine,” 2018) showed one extra hour of daily sunlight correlates with a 2.4% price premium.
For pre-construction agents, this turns sunlight into a real sales lever. Two buyers comparing similar units at similar prices will often choose the one with better afternoon light in the living room, if they can see it. Without simulation, the agent waves their hand at a printed floor plan and says “this one faces west, so…” The buyer has to imagine the rest.
R2U’s 3D sales platform changes the conversation from imagination to demonstration. The agent picks the unit, drags the time slider to “winter, 4 p.m.,” and the buyer sees exactly where the sun hits the kitchen counter.
How the technology works (in plain terms)
Three layers combine to produce a pre-construction sunlight simulation that a buyer can interact with.
Layer 1, the 3D model. The developer supplies architectural files (Revit, ArchiCAD, SketchUp, or BIM exports) covering the building shell, floor plates, unit interiors, and the neighboring buildings within ~500 meters. Neighbors matter because they cast shadows. Modeling them at low fidelity (massing only) is enough for accurate shading.
Layer 2, solar position math. For any (date, time, latitude, longitude), solar altitude and azimuth are computed using NOAA solar position equations. WebGL fragment shaders then evaluate, per pixel of each visible surface, whether a ray from that pixel to the sun is blocked by any geometry. Blocked = shadow. Unblocked = direct sunlight. This runs at 60 frames per second on a mid-range smartphone, so the buyer drags a time slider and watches shadows move in real time.
Layer 3, the interface the buyer touches. On R2U’s 3D sales platform, the buyer (or agent) selects a unit, then opens the sun-path panel. A time slider covers a full year. A second control selects time of day. The 3D model updates instantly, showing shadow patterns inside the apartment, on the balcony, and across the facade. On Apple Vision Pro, the same simulation runs at full architectural scale, so the buyer walks through a life-size apartment with accurate light streaming through actual window positions.
This second layer is where R2U’s browser-based delivery matters. The buyer never installs an app. The agent shares a WhatsApp link from the sales gallery; the buyer continues exploring sunlight on different units from home. Existing-home sunlight tools require a download (iOS app or studio license). Other 3D sales platforms run as native apps that need install on every device. R2U runs in any browser via WebGL.
What pre-construction sales teams use sunlight simulation for
Sales teams use sunlight simulation as a differentiation tool between similar units, as an objection-handling tool when buyers hesitate, and as a way to justify price differences between floors or orientations.
Unit differentiation. In a 100-unit tower, units 1801 and 2001 may have identical floor plans but face different directions. The price difference (5-15% in many markets) is partly justified by light. Showing the buyer the exact difference at 4 p.m. in July makes the price gap concrete.
Objection handling. A buyer concerned that a lower-floor unit will be too dark can see the actual hours of direct light it receives across all four seasons. Often the unit is brighter than feared (the next building over is shorter than the buyer assumed). Sometimes it is darker, but the buyer makes a real decision rather than walking away on a guess.
Price justification. Developers commonly price south-facing or corner units at a premium. The hedonic studies cited above (Shanghai 7.2%, “Valuing sunshine” 2.4% per hour) provide the academic basis, but the buyer wants to see it. Sunlight simulation provides the visual proof for the premium.
VIP previews and broker training. Brokers who can demo sunlight live during a sales gallery tour outperform brokers who hand out PDFs. R2U has deployed 3D sales platforms with sunlight simulation at developers like Tegra (Brookfield subsidiary, 104K+ units delivered) and MPD (3rd largest builder in Brazil by INTEC 2025). Sales teams demo the same model in the gallery, on a tablet at a coffee meeting, and on Apple Vision Pro for high-end buyers.
How R2U does sunlight simulation differently from existing-home tools
The dominant US sunlight tool today is Shadowmap, integrated into Redfin’s Sunscore (launched May 11, 2026, US exclusive via Rocket). It covers every existing for-sale listing nationwide using OpenStreetMap building data. It is the right tool for resale buyers comparing 30 listings on Redfin. It is the wrong tool for a buyer choosing among 40 units in a pre-construction tower that does not appear on any map yet.
Pre-construction needs three things existing-home sunlight tools do not provide: the unbuilt building modeled at unit-by-unit fidelity, integration with the rest of the sales conversation (unit selection, finishings, pricing), and a delivery format that fits the sales gallery (tablet, large touch display, Apple Vision Pro).
R2U’s 3D sales platform delivers all three because sunlight is one feature inside the platform, not a standalone tool. The same model that shows sunlight on unit 1801 also shows the kitchen finish options, the real view at floor 18, and the live availability of the unit. The agent does not switch screens. The buyer does not lose context.
The browser-based delivery also matters for the buyer-at-home moment. R2U opens in any browser via WebGL: no app, no download. The agent shares a link by WhatsApp, the buyer opens it on the couch that evening, drags the sun-path slider, and shows their spouse why unit 2102 is worth $40,000 more than unit 1502. Photo-based virtual tours cannot do this. Native apps lose the buyer to the install friction.
R2U’s pricing for the 3D sales platform starts at approximately $2,700 (R$ 15,000), with Apple Vision Pro experiences from approximately $5,400 (R$ 30,000), a fraction of the $90,000-$360,000+ a physical model unit costs for a luxury pre-construction project. Sunlight simulation is included, not an add-on.
What other features sales teams should expect alongside sunlight
Sunlight simulation rarely ships alone in a serious pre-construction tool. The four features that matter together are sunlight, real view by floor level, unit comparison, and finishing customization.
Real view by floor. Photogrammetry or drone capture of the actual surroundings, mapped to each floor’s window position. The buyer on floor 28 sees what they will actually see, not a generic city render. Combined with sunlight, the buyer understands both what light comes in and what view they see when they look out.
Unit selection and comparison. A live grid of all units in the building with availability, price, floor, orientation, and configuration. Filter by sunlight rating, by view, by price. Compare two units side by side. R2U builds this into the 3D sales platform by default, often combined with an interactive masterplan for multi-tower developments.
Finishing customization. Real-time material swaps on floors, countertops, and fixtures, using the developer’s actual material library. Combined with sunlight, the buyer sees how the white oak floor looks at 9 a.m. versus the dark walnut at 6 p.m.
Apple Vision Pro for scale. The buyer steps through a life-size, fully decorated apartment with the same sunlight model running at architectural scale. R2U has delivered Apple Vision Pro experiences for Tegra (RIIO by Piero Lissoni, Barra da Tijuca, 132 units), MPD (Reffugio 359 Smart, 106 studios), Flamboyant Urbanismo (Autentico Residential, iF Design Award 2026), and Vincere (Arte Batel, designed by Fernanda Marques).
The combination matters more than any single feature. A pre-construction buyer making a $500K-$3M decision wants to see everything: sunlight, view, finishes, scale. R2U builds them into one platform that shares via a browser link.
FAQ
How accurate is sunlight simulation for pre-construction real estate?
Accurate to within minutes of true solar position when the source 3D model includes nearby buildings within ~500 meters. The math (NOAA solar position equations, ray-traced shading) is the same physics-based calculation used by architects and urban planners. Accuracy depends on input data: a model with neighboring buildings, terrain, and tall vegetation produces results matching reality. A model with only the subject building will overstate sunlight because it ignores shadows cast by neighbors.
Can buyers see sunlight simulation on their phone?
Yes, for browser-based 3D sales platforms. R2U’s platform runs via WebGL in any modern smartphone browser, with no app install. The buyer opens a link shared by WhatsApp or email, picks a unit, and drags the time-of-day slider to see shadows move in real time. Native-app 3D sales platforms require download on every device. Existing-home sunlight iOS apps cover resale listings only, not unbuilt pre-construction units.
What is the difference between Sunscore on Redfin and pre-construction sunlight simulation?
Sunscore rates existing listings on Redfin from 0-100 using Shadowmap’s city-wide building data. Pre-construction sunlight simulation runs inside a 3D sales platform on the developer’s own model of the unbuilt project. Sunscore is a discovery filter (“which listings get good light?”). Pre-construction simulation is a sales tool inside the gallery (“here is exactly how light moves through unit 1801 in summer versus winter”).
How much does sunlight simulation cost for a pre-construction project?
Sunlight simulation is typically included in the 3D sales platform as a default feature, not priced separately. R2U’s 3D sales platform starts at approximately $2,700 (R$ 15,000) for a standard project, with Apple Vision Pro experiences from approximately $5,400 (R$ 30,000). For reference, a physical model unit costs $90,000-$360,000+ for a luxury pre-construction project. Pricing varies by project scope, unit count, and number of finishing options.
Does Apple Vision Pro change what buyers see in sunlight simulation?
Yes, in two ways. First, scale: the buyer walks through a life-size apartment with light streaming through actual window positions, instead of looking at a 3D model on a screen. Second, presence: the spatial computing feel of the Apple Vision Pro lets buyers perceive light intensity and direction the way they would in a real apartment. R2U has delivered 8+ Apple Vision Pro projects for real estate (Tegra, MPD, Coelho da Fonseca, Flamboyant, Vincere, Ferreira), more than any company in Brazil.
Can sales teams customize the time range shown in the simulation?
Yes. R2U’s platform exposes a full-year time slider (date and time of day), so agents can demo the unit at solstices, equinoxes, or specific dates buyers care about (e.g., “what does the kitchen look like on Christmas morning?”). Common preset views include June 21 noon (peak summer), December 21 noon (peak winter), 8 a.m. and 6 p.m. across all seasons. Agents customize the presets per project.
Why don’t all pre-construction developers offer sunlight simulation?
Three reasons. First, many sales galleries still rely on physical scale models and printed floor plans, where sunlight cannot be demonstrated at all. Second, photo-based virtual tour tools (the existing-property category) skip pre-construction entirely. Third, the developers who do offer 3D sales platforms often use native apps that work on iPads in the gallery but not on a buyer’s phone at home. R2U’s browser-based 3D sales platform with sunlight simulation runs everywhere, which is why developers like Tegra and MPD adopted it.
Written by
Giovanni Abeni
CTO — R2U
Giovanni Abeni has been CTO of R2U since the company's early years. A graduate of Escola Politécnica at USP, he worked at Espresso Labs and Converge before taking technical leadership at R2U. He owns the architecture of the platform that runs interactive models in the browser (WebGL), virtual staging in augmented reality, and spatial computing experiences with Apple Vision Pro. Under his technical leadership, R2U has delivered projects for companies including Mobly (+82% conversion), Tegra, Coelho da Fonseca, and Portobello.
LinkedIn →
