How to plan a building projection show

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Eightstages, in the order they actually happen, and the decisions at each one thatdetermine whether the show works on the night.

A buildingprojection show looks effortless when it works. A facade dissolves, a monumentmoves, and a few thousand people stop walking and look up. Getting there ismostly planning, and most of the planning happens weeks before anyone brings aprojector to site.

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This is thesequence we follow, and what tends to go wrong when a stage gets skipped.

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1. Start with the outcome, not the building

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Before anythingtechnical, settle what the audience should walk away with. A launch that needsa product understood, a national moment that needs to feel significant, and afestival that needs a crowd to stay for the next act are three differentbriefs, and they lead to three different shows on the same wall.

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Decide the runtime here too. Most facade shows land between three and eight minutes. Shorterthan three and the story cannot build. Longer than eight and a standingaudience begins to drift, unless the piece is looping for people who arrivethroughout the evening.

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2. Survey the site before promisinganything

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The site surveydecides what is possible. Five things get measured, ideally at night, at thesame hour the show will run.

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Throw distanceand projector position. How far back can equipment sit, and is there a clearline to the facade? Trees, lamp posts, signage, and overhead cables all blocklight, and a branch that looks minor in daylight will cut a hole in the image.

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Sightlines forthe audience. Where will people stand, and can they see the whole surface fromthere? A show designed for a head on view falls apart when the crowd is pushedto one side by a barrier nobody mentioned.

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Ambient Light.This is the single most common reason a show underperforms. Street lighting,shop signage, passing headlights, and floodlights on the building itself allcompete with the projection. Establish early who can switch what off, and getit agreed in writing.

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Power.Confirm what is available, how clean it is, and how far it sits from theprojector position. Most shows of any scale run on generators with backup,because a dip on the mains at the wrong moment ends the show.

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Access.When can equipment come in, how long is available for setup, and when musteverything be cleared? On public and heritage sites this window is often a fewhours in the middle of the night.

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3. Start permissions early, because theytake longer than production

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For anything ona public building, permissions usually set the schedule. Depending on the siteyou may need the building owner or custodian, the local authority, police ortraffic management if the audience will occupy a street, a heritage body if thestructure is protected, and sometimes a separate approval for the contentitself.

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Contentapproval is the one that surprises people. On government and heritage projects,the visuals may need signing off by someone who is not in the room during thecreative process, and revisions at that stage are expensive. Ask at the outsetwho has final say on what appears on the building.

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4. Read the surface honestly

The facade isthe screen, and it is rarely a good one. Pale, flat, matte surfaces reflectlight best. Dark stone absorbs it, so a black marble facade may need severaltimes the brightness of a whitewashed one for the same result.

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Texture cutsboth ways. Deep carving, ornament, and relief create shadows that break up flatvideo, but they are also what makes architectural projection worth doing,because content built around those features looks like it belongs to thebuilding. Glass is the hardest case, since it reflects rather than holds light,and large glazed sections usually have to be designed around rather thancovered.

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Colour mattersas well. A strongly coloured facade will tint everything projected onto it,which either becomes part of the palette or has to be corrected for in thecontent.

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5. Work out brightness properly

Brightness iswhere budgets are won and lost, and it is not a single number. It depends onthe area of the facade, the reflectivity of the surface, and how much ambientlight remains once everything that can be switched off has been.

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A modest, palefacade in a dark setting may be well served by a single high output projector.A large monument in a lit city centre can need several, stacked to doublebrightness on the same area and blended across the width of the building.Stacking and blending are also what allow the image to stay sharp across a widesurface rather than stretching one projector past its useful range.

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The practicalrule is to specify brightness for the worst realistic conditions rather thanthe ideal ones. A show that is calibrated for a fully dark site and then has torun with the street lights on will look washed out, and there is no fixing thaton the night.

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6. Build the model, then design for it

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Content isdesigned for one specific structure, so the structure has to exist digitallyfirst. That usually means a laser scan, photogrammetry from a drone or camerapositions, or architectural drawings where they are accurate and available. Theresult is a 3D model that matches the real geometry closely enough to designagainst.

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From there theshow is previsualized on the model, with the projector positions from thesurvey applied, so the team can see roughly what the audience will see beforeanyone travels. This is where most creative problems get found and solvedcheaply.

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The designprinciple worth holding onto: anchor motion to real architectural features.Windows that open, columns that carry weight, arches that fill with light.Video that ignores the building reads as a screen bolted to a wall. Video thatrespects it makes the building appear to be doing the moving.

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Sound is partof this stage, not an afterthought. A projection show without audio feelsstrangely incomplete, and the timing of the edit is usually driven by the trackrather than the other way around.

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7. Test on the actual surface

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Previsualizationgets you close. It does not get you there. On site, the alignment is refinedagainst the real geometry, brightness and colour are corrected against the realsurface, and the blends between projectors are matched so the seams disappear.

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Test at thehour the show will run, in the lighting conditions it will run in. A rehearsalat two in the morning on an empty, unlit street tells you very little about ashow that goes out at eight in the evening with traffic moving past.

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Build in atleast one full technical rehearsal before the first public showing, and treatthe media server, content, and cue stack as things that need a backup ratherthan things that will be fine.

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8. Plan the night itself

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The show is onepart of an evening that also involves an audience arriving, a crowd standingsomewhere, and often speeches or performance around it. Agree the runningorder, who calls the cues, and what happens if the previous item overruns.

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Weather needs aposition too. Rain covers for equipment, a wind threshold above which nothinggoes up, and an agreed call time for postponement. Humidity can fog a lens, anda projector position that is exposed on a rooftop is a different proposition inAugust than in January.

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Finally, planhow the show is captured. A projection show exists for a few minutes and thenit is gone, and the footage becomes the asset that lives on afterwards, for theclient and for everyone who could not be there.

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How long all of this takes

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For mostprojects, six to twelve weeks from brief to show night is realistic. Astraightforward facade using existing brand assets can move faster. A monumentwith original 3D content, a custom score, and multiple approval stages takeslonger.

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The variablethat moves the schedule most is rarely production. It is permissions andcontent approval, which is why both are worth starting in the first week ratherthan the fourth.

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Common questions

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Can any building be used for projectionmapping?

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Most can,though some are far better suited than others. Pale, matte, textured facadeswork best. Dark stone, heavily glazed frontages, and buildings with no clearprojector position or audience sightline are harder and sometimes not worth thecost.

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Does projection mapping damage thebuilding?

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No. Light isthe only thing that reaches the surface. Nothing is drilled, fixed, orattached, which is why the technique is used on protected and heritagestructures where physical installation would never be approved.

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What time of year is best for an outdoorprojection show?

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Cooler, driermonths are easier, mainly for equipment safety and earlier darkness. Summershows are entirely possible but start later, since the projection cannot beginuntil the sky is genuinely dark.

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How many projectors does a building projection show need?

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Anywhere fromone to a dozen or more. It depends on the width of the facade, the reflectivityof the surface, and how much ambient light remains. Wide buildings need severalblended across the surface, and dark ones often need projectors stacked forbrightness.