XPRIZE Reskinning Buildings

Today’s urban populations are expanding and growing in density at a pace that is difficult for many existing cities to match. The need for smarter housing, mobility, waste management and energy efficiency is increasing, but the options to build new infrastructure are limited. Most infrastructure is here to stay for another 40 decades, and existing buildings are particularly seeing the least progress in emissions reductions. As a result, we need to focus on retrofitting the existing infrastructure.

The possible focus areas for this prize are:

  • Retrofit an industrial facility.
  • Repurpose old coal and gas plants to support clean energy.
  • Retrofit existing buildings: Buildings are a major source of emissions and account for a third of primary energy consumption. Solutions may include electrification, the use of CHP systems and e-fuels, thermoelectric paint, and smart windows, and more.

We would like to learn from you:

  • What are the innovation gaps in this area?
  • What would the winning team need to do?
  • What would be audacious but achievable targets?
  • What is the expected impact of this prize?

Hi @akb, @Jesse_Nyokabi and @darlenedamm - What is your thoughts on this prize idea? Do you think it is audacious enough to be the next XPRIZE? What could the Impact of such a competition?

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In general ideas across this sector are fairly traditional, so here’s a few audacious ideas for retrofitting.

Rapidly deployed low cost solar roofs that generate solar power and provide thermal insulation (to conserve heat). Rapid deployment and low cost mean we can quickly update existing properties within the climate change emergency time-frame. Low cost means the solar power and thermal insulation have a return on investment within 10 years. Deployment requires an audacious innovation - probably automation.

Perhaps… Windows that provide excellent thermal insulation, perhaps with solar powered electricity generation, and the ability to tint the windows on demand (graduated from opaque to transparent). In addition to the obvious energy benefits it would remove the need for curtains and blinds. I’m a little more hesitant about this idea, as installation costs might still be relatively high, and the benefits relatively low. The incident solar radiation on a vertical window is relatively low. Unless a very low cost (automated) installation solution is possible [very difficult]. (Just floating this idea.)


Hi @Shashi
Regarding waste:-

An in house or in garden unit to rapidly turn food (and garden) waste into electricity. For example, a waste bin sized device in the kitchen accepts food waste at the top and provides processed solids at the bottom (which may be used as compost, or for another purpose). Unlike slow composting, the successful solution would process waste within a day (or so).

Additionally, for some hot dry regions, it would be great if the device also produced safe drinking water.


Thanks @akb for sharing your thoughts and the ideas. We have taken note of these ideas and would share it internally with our team and domain lead. We would contact you in case we require any more details.

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Thank you @akb regarding your comment on waste! Our team had indeed considered a similar idea of converting common household waste items back into something usable–your suggestion (into electricity) in my mind seems like the most useful and obvious commodity to produce. Personally speaking, I like it! :slightly_smiling_face: We’ll keep workshopping this idea in the background, but in the meantime it seems like the Brain Trust wants to keep the focus for now on larger infrastructure projects such as office buildings, power plants, or industrial facilities. Thanks again!

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Hi @JessicaYoon Thanks for the feedback.

Regarding larger infrastructure projects: the same waste processing device [and XPRIZE challenge] can be used on a community scale to produce electricity and water for whole urban areas (cities, towns and villages).

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Hi @Brad, @AlexIp and @agval - In your views, what should be the focus area of this prize and why? What are the innovation gaps in this space?

We’re wordsmithing what we call the “winning-team-will statement” for this prize: a succinct description of what a competing team would need to do to win.

Here’s the current version, and I’d appreciate your thoughts:
Reskin a building for the lowest cost, reducing energy demand by X% and increasing the share of renewables by Y%, introducing a 40% increase in savings.

The next step are drafting the testing and judging criteria for the prize. Here’s what we have so far:

  • Skin a building
  • For less than US$1 per square foot
  • Reduce energy demand/intensity by X% or more
  • Increase reliance on renewables by Y% or more
  • Other costs:
    • Net savings: 40%
    • Net cost balance: energy saving vs. cost payback ≤5 years
  • At the highest sustainability score
  • and least modifications to infrastructure.
  • Lifetime matches building’s (remaining) lifetime
  • Leave the building visually pleasant when installed,
  • Do not cover natural light (e.g. windows) in the building.

@akb, @Jesse_Nyokabi, @gyyang, @CO2Cap_SysEng - We would love to hear your feedback on this wining team will statement and the testing and judging criteria.


That looks good.

“Increase reliance on renewables” - Does this mean using renewable energy generation on the building itself, or using renewable energy via the infrastructure / external sources? The former makes sense and is easy to quantify.

“Other costs” - The 40% and years to payback are related, and could be calculated given an average scenario, and building area (at $1 / sq ft). [I don’t know what a 40% reduction equates to in terms of years to payback - I’ve not done the calculation. Did it come to the 5 years mentioned above?]

“highest sustainability score” - these are difficult to accurately define and quantify.

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I would support it 100%.
We need to retrofit some of this infrastructures.

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Hi @agval, @darlenedamm, @Access600 - You might have feedback to share on the above mentioned wining team will statement and the testing and judging criteria.

Hi Shashi,
I agree with akb in the sense that some of these parameters need to be quantifiable. As long as there is a method to do so, I think the proposal is ready to go.

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Hi @b0bbybaldi, @Sunbeam and @KeithDPatch - We feel you might have feedback to provide on the metrics of this competition on reskinnning buildings. Please advise us on this competition.

@Shashi indeed I would focus on leveraging existing metrics as the baseline or even guidelines for qualifying such solutions. Look into USGBC’s LEED as the leader in this space https://www.usgbc.org/. For more potential guidelines look into other existing certification giving bodies: https://www.sharplaunch.com/blog/green-building-certifications/.

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What if this issue is answered by one of the contender technologies for a different prize. Our direct air capture technology sequesters the captured CO2 as magnesium carbonate in a form that is fireproof, thermally insulating, resistant to weather and light weight - ideal for wall cladding. Can we apply for both?

Hi @CamCarbonCapture,
We would like to clarify a few things, as of now we are requesting your advise on the prize design. Post the launch of this or any other prize, you can apply for as many prizes you like.

OK, my idea is to work with an established construction industry testing house. In the UK we have the Building Research Establishment (BRE). Pay them to build a test house and enable prize entrees to install their systems for testing, again, paid for by Xprize. This could be expensive for a smaller start up so maybe smaller test cells could be produced for initial testing. Ideas showing promise could receive funding sufficient to produce samples for testing at the test house scale.

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Hi @Shashi

In my opinion, the following metrics could be taken into consideration

Recovery of wastewater from buildings gray water, drainage water for reuse with the highest purity possible( there are electrolysis technologies that already meet this objective).

Rainwater harvesting
There are many traditional methods for water harvesting; it is important to consider more innovative projects that take advantage of the surface of the architectural space; for example there are methods to recover water by emulating groundwater harvesting (like the example image of RainGuardian’s methodology) by placing rainwater channels under the grass or sidewalks and directing them to water containers buried below ground.

Water generation
is another important metric to consider in the contest, in certain regions of the world there is the possibility of generating water from the relative humidity of the atmosphere.

Currently there are methodologies to capture energy in addition to solar panels and wind. I have seen projects where glass can generate electricity; I think it is important to consider projects that make the best use of architectural space to capture electricity.

Inorganic waste
The management of inorganic waste in a decentralized way is a good alternative to mitigate the effects of landfills, since not all waste is recyclable but it is possible to treat it by pyrolysis at the site of generation. It would be important to consider the compliance with this metric in the competition, since there are currently compact technologies that can be installed in a building to treat waste.

Organic waste
use of organic waste for composting

when it comes to residential buildings, a desirable metric could be on-site food generation, on-site food production (where possible) can mitigate the side effects of the food production we currently have by agro-industrial methods.

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Based on the advice of our founder and chairman, Peter Diamandis and other experts, we have revised the prize metrics.

Following is the revised wining-team-will-statement:
Reskin’ an existing, 1960s-built, 4-unit building, for less than US$1 per square foot, in under 30 days, aesthetically and without service disruption: reducing energy consumption by 25% per square foot and 10% in total, while cutting the carbon footprint by ≥50% and payback time to ≤5 years.

Following is a draft testing and judging criteria for this prize:

Semifinals: prefabricated home/modular homes/mobile homes (size 24X60); existing skin material is steel.


  • Reskin* an existing building (older than 20 years, 4-unit, low-income residence); existing skin is concrete.
  • In under 30 days, without disrupting use of the building
    • All existing doors and windows should be able to remain in the structure as openings to the buildings.
  • Insulation value from the skin: R ≥30 on all skin’s surfaces
  • Reduce HVAC energy consumption by 40%
  • Reduce total carbon footprint by at least 50%
    • Bonus, increase the share of renewables: use the skin to capture renewable energy, most kWh per square foot.
  • For ≤$2 per square foot of surface and total payback of ≤36 months
    • Installed cost of skin : ≤$2 per square foot of surface area (replacement of windows and doors does not count against the cost)
    • Measure the payback based on 15c/kWh electricity and $3 for mm BTU gas with a total payback of ≤36 months.
  • Lifetime: ≥30 years of useful and aesthetic life (with no maintenance)
  • At the highest sustainability score for materials used (LCA and EoL plans)
  • Safety: outgassing of volatile materials shall not exceed EU standards
  • Flexible: can be applied to any building and any geography

@Sunbeam, @akb, @Jesse_Nyokabi, @agval, @b0bbybaldi - We would love to have your feedback on the revised wining team will statement and the testing and judging criteria.

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