Around the world, a number of buildings are taking part in the Living Buildings Challenge, a program describing itself as the “most advanced measure of sustainability in the built environment”; where in simplified terms, buildings give back more than they take. The current list of six certified projects includes several education and research facilities, a community centre and a home, with over 140 more projects under development. Could a high rise make this list? Should it? And if it can’t, what does that mean for the Living Building Challenge?
The Living building Challenge is a philosophy, advocacy tool and certification program focusing on seven performance areas: site, water, energy, health, materials, equity and beauty. Projects must (among other things) be net zero energy on an annual basis, have distance restrictions on material sourcing, must have operable windows, purchase carbon offsets for the embodied energy and prove its performance with actual measured data after 12 months of operation.
The six certified projects are truly fantastic creations, including an educational wastewater filtration facility, a high school energy lab, an environmental field station, a combined community café, art gallery, and office, and a home in snowy British Colombia.What jumps out from these projects though is that they are all low density (people per square meter/foot) facilities powered primarily by photovoltaics.
Concept for Seattle's BullittCenter, aiming for Living Building Certification. image c/o Miller Hull
Seattle’s BullittCenter, in attempting to meet the Living Building Challenge, shows a great example of an office building striving to supply its own energy, water and waste needs (though under construction). The six story office building has a design life of 250 years, is expected to use just ¼ of the energy of a typical building, and be water self-sufficient. The building will be powered by a “sombrero” of solar panels on the roof, so many that it had to negotiate air rights over the surrounding pavement area. This gives an indication as to the maximum size at which office buildings can operate self-sufficiently.
Large ‘high rise’ buildings on the other hand (greater than say seven stories) are typically more people-dense (one person per 10-15m2) than those educational/research facilities already certified under the Living Building Challenge (one person per 20-40m2). And unlike the BullittCenter, larger high rise buildings have a much smaller roof area per floor area (typically less than 5% of the total floor area), ensuring that the buildings’ consumption cannot be met by on-site renewable energy.
So, it looks like high rise towers have a high utilisation of space, but would struggle to meet Living Building Challenge standards because they have a small roof and therefore can’t generate enough energy. Just as office buildings look to optimise space for ‘work’ (and help with transport and land use intensity), could we look to optimise energy generation in locations that are best suited, in high energy density, low land cost areas? This would mean allowing the decoupling of productive ‘work’, environmental restoration and energy generation.
The Energy Lab, Hawaii Preparatory Academy, certified by the Living Buildings Challenge. Image c/o greenbuildingelements.com
The Living Buildings Challenge’s concept of ‘regenerative’ generally focuses on the design and construction of new buildings or significant redevelopments/refurbishments, taking into account site, water, energy, health, materials, equity and beauty. Health includes some metrics focussed on people, such as air quality, natural light and ventilation standards.
This led us to think about how these metrics might relate to existing buildings, where sustainability improvements can be done via more modest refurbishments and behaviour change programs, for big environmental gains. These are the kind of projects typical to the portfolio of buildings available for scrutiny on this site's datalyzer. In the case of existing buildings, site, materials, equity and beauty could be treated as ‘sunk’ because they’re not able to be changed. That leaves water, energy, and health as the variables to be rated. In line with discussions we’ve been having on Green Buildings Alive, those metrics could be evaluated in terms of utility or service, rather than in absolute terms. For example, perhaps there’s a way to measure impacts as a ratio of energy or water use to production, output or comfort, so we recognise that the building's inputs (energy, water) produce outputs (work-hours, occupant satisfaction). If this were done, I suspect some existing buildings may rate very highly. New high rises might do well under this kind of measurement too. But we don’t know, of course. It’s all guessing because integrated environmental/people measures do not seem to exist. The NABERS system in Australia and Energy Star go part of the way, by evaluating intensity of resource use, but there’s scope for the development of efficiency measures.
Here at Green Buildings Alive we have been inspired by the Living Building Challenge and vision for the future of building. But bearing in mind 97% of today’s office stock is ‘existing’, it will pay to keep focus on improving the performance of existing high-rises too. Integrated approaches will help, for example, offsite energy generation and water collection and more of a focus on energy ‘productivity’ within the building, based on real, measured data. Living Buildings Challenge principles applied to ongoing building operations could reveal some very interesting results and help justify a more concerted focus on doing better with what we’ve already got.
Large high rise buildings do provide 'on-site' opportunities that can ensure they meet their renewable energy needs. Facades provide spandrel areas (up to 50%) that can be utilized to optimise 'on site' energy generation. Photovoltaic panels mounted horizontally can also provide shading and can be used as a medium to harnessing rainwater. An enterprising and aesthetic solution can improve energy performance, optimise values and help beautify the 97% stockpile of existing buildings.
These types of buildings are really needed ,especially in Africa where the sun light is abundant . We do need international cooperation ( MDG No 8) and ease in technology transfer . for sustanable cities all over the world