Cost-Effective Retrofits: 7 Steps to Zero Energy
CategoriesSustainable News Zero Energy Homes

Cost-Effective Retrofits: 7 Steps to Zero Energy

How to use the 7 Steps

Building professionals can use the resource to inform clients and help explain sustainable design-build processes that maximize energy efficiency and cost-effectiveness. All eight pages are easily integrated into PowerPoints, and are free to share with colleagues. A builder’s or architect’s website can reference the steps as a proven methodology that is part of their corporate mission. And it’s easy to write and post case studies that show how a project successfully followed the steps.

The design and construction team work together to integrate each step’s purpose and strategies. So the 7 Steps spur discussions on where additional evaluations and expertise may be required, and how the different trades can be impacted. There are reminders that existing buildings are all different and that upgrades will interact with each other, so sequencing and phased implementation require careful consideration. Future maintenance requirements and expected lifetimes of different systems are major factors in determining the lifecycle cost and carbon accounting.

Think globally, act locally

Construction Worker Installing New Windows In apartment

The ZERO Coalition unites businesses, nonprofits, and local governments to propel our shared goal to change how we build and retrofit our homes and businesses. We seek to reduce buildings’ carbon footprint and electrify them with clean energy. As a coalition, we are accelerating the transition to a decarbonized building sector in Oregon. But builders, designers, policymakers, and other members of the sustainable building industry can use the 7 Steps to advance building decarbonization anywhere in North America, and beyond.

Buildings in Oregon account for about 30% of Oregonians’ energy use and 40% of our GHG emissions, the most significant chunk after transportation. According to Rocky Mountain Institute, buildings also account for 40% of global energy GHG emissions. Architecture 2030 found that “To accommodate the largest wave of building growth in human history, from 2020 to 2060, we expect to add about 2.6 trillion ft2 (240 billion m2) of new floor area to the global building stock, the equivalent of adding an entire New York City to the world, every month, for 40 years.” This is why building decarbonization is finally getting wider attention. The time is now.

Reference

Citizens Design Bureau retrofits Jacksons Lane arts space in London
CategoriesInterior Design

Citizens Design Bureau retrofits Jacksons Lane arts space in London

UK studio Citizens Design Bureau has given a colourful retrofit to Jacksons Lane, an arts and circus centre in an old church in London, with the aim of decluttering and simplifying its interior.

The studio aimed to improve the functionality of the grade II-listed building, which used to be a church but has been a community hub and “leading centre in contemporary circus arts” since the 1980s, Citizens Design Bureau said.

Retrofitted Jacksons Lane community centre
The Jacksons Lane building has a colourful interior

“The previous layout was a real jumble of spaces that didn’t work from a functional perspective,” the studio’s director Katy Marks told Dezeen.

“Our approach was to declutter the old church building, so that the original structure was more visible, giving a sense of the symmetrical cruciform of the original plan and using the drama of those spaces to full effect, improving acoustic separation, functionality as well as making the building fully accessible,” she added.

Interior of community u=hub by Citizens Design Bureau
Spaces were rearranged to create a more functional interior

The venue in Highgate, London, had a dated interior with more than 20 different levels.

While reconfiguring its spaces to make them more functional, Citizens Design Bureau added a cafe and hireable studios in the former church’s double-height transept.

Red walls in Jacksons Lane in London
Red and teal colours brighten up the space

New details that make Jacksons Lane more functional include acoustic windows, as well as ramps and lifts that create easier access to the different spaces.

It also restored some parts of the church that had been hidden under more recent interventions. This included reinstating the main entrance of the building to the original church porch, which had been boarded up.

“You would often see people still climbing the steps up to the original, boarded-up door, trying to push it open,” Marks said.

“In a grade II-listed building, we had limited scope to make big changes to the exterior, so we felt that opening up the original and intuitively obvious entrance was the most impactful move we could make, to make the building much more legible and welcoming to everyone,” she added.

Orange wall and teal details inside community centre by Citizens Design Bureau
Citizens Design Bureau retrofitted the arts centre in Highgate

Inside the centre, Citizens Design Bureau introduced a warm colour palette of deep reds and oranges with teal accents, which complements the existing brick, stone and dark-wood details.

“The building has undergone many changes over decades of use, so the internal fabric in particular has a layered history,” Marks said.

“We have used colour to express those layers – white for the church structure, a teal blue for elements that were added in the 70s, and then volcanic oranges, reds and purples for completely new insertions with pops of other colours in the lighting, reflecting the playfulness of its current function as a creative space, specialising in circus arts.”

Room inside Jacksons Lane in London
Whitewashed walls contrast dark-wood floors

The studio clad some of Jacksons Lane’s ceilings with a pale-green concertina form that improves acoustics.

Lamps with bright orange cables add another colourful touch to the space.

View of community centre by Citizens Design Bureau
The former church is now used as an arts and circus hub

Jacksons Lane is used by a lot of people in the local area and Marks said the feedback so far has been “wonderful”.

“We hope that what we have done really expresses the ethos and character of Jacksons Lane with clarity and a bit of joy, raises a smile and is the kind of place that people really want to hang out in,” she said.

Citizens Design Bureau has previously added a “delicately perforated” Corten extension to Manchester Jewish Museum, for which the studio was longlisted for a Dezeen Award in 2021.

The photography is by Fred Howarth.

Reference

Tackling Embodied Carbon in Retrofits
CategoriesSustainable News Zero Energy Homes

Tackling Embodied Carbon in Retrofits

A firm specializing in remodeling rethinks its approach to attic and roof insulation to lower embodied carbon.

By Rachel White

In 2018, the Intergovernmental Panel on Climate Change (IPCC) put the world on notice: To avert catastrophic and irreversible climate change, we will have to hold global warming to 1.5°C above pre-industrial levels. And to keep warming at this level, we must cut global emissions roughly in half by 2030 and get to zero by 2050.

Building Sector Contributions to Global Warming

The building sector is a huge part of the problem, accounting for roughly 40% of global annual emissions. And while our industry has made progress, we haven’t done nearly enough.

Along with the work of organizations such as the Carbon Leadership Forum and Architecture 2030, the IPCC report was a wake-up call about the time value of carbon. Larry Strain, a board member at the Carbon Leadership Forum, describes it this way: “Because emissions are cumulative and we have a limited amount of time to reduce them, carbon reductions now have more value than carbon reductions in the future [emphasis added].”

Carbon Reduction Strategies                                                          

Three strategies are critical to achieving meaningful near-term reductions in building sector emissions. First, we need to repurpose buildings rather than build new ones wherever possible. Second, we need to aggressively reduce the operating emissions of existing buildings. Third, we need to build with low embodied carbon materials and ideally with carbon-storing materials.

The first two strategies are firmly ensconced at Byggmeister. We don’t do new construction, we avoid additions, and we pursue operational emissions reductions whenever possible. However, until the last couple of years, we had not paid much attention to embodied carbon. We assumed that whatever carbon we emitted to renovate and retrofit homes would be balanced by operational savings over decades. But this assumption was flawed.

Embodied Carbon Emissions

So, we turned our attention to embodied emissions, focusing first on insulation. As remodeling contractors, we know that insulation is high leverage, especially because closed-cell spray foam—one of the highest embodied carbon insulation materials on the market—has long been a go-to insulation material for us. There are good reasons we have relied so heavily on closed-cell spray foam. It blocks air leaks in addition to reducing conductive heat loss; it’s vapor impermeable; and it’s highly versatile. But none of these is a good reason to maintain the status quo.

Deciding When to Use Foam

There are times when replacing spray foam with a carbon smarter material is a no-brainer. For example, installing cellulose in wood-framed walls is typically no more complex than insulating with spray foam, not to mention less expensive and less disruptive. And while the R-value of a cellulose-insulated wall is lower than the same wall insulated with closed-cell spray foam (unless the wall assembly is thickened), we believe this compromise is worth it. The reduced R-value has little impact on comfort and the carbon benefit more than makes up for it. Unlike spray foam, which emits a lot of carbon before, during, and immediately after installation ( especially true of closed-cell spray foam with high-embodied-carbon blowing agents), cellulose actually stores carbon.  

There are other cases, though, such as with rubble foundation walls, when we feel spray foam is the only viable choice, other than not insulating at all. While we have entertained this possibility, we aren’t willing to give up remediating dank, damp basements, although we have begun to think about these as emissions that should be offset with more aggressive carbon-storing measures elsewhere.

Roof Insulation Challenges

Much of the time, though, the choice to eliminate or retain spray foam isn’t clear-cut. We encounter many roofs and attics where existing conditions, code requirements, and broader project goals make it challenging but not impossible to avoid spray foam.

If the attic is unconditioned, then the easiest, most cost-effective strategy is to air seal any penetrations along the attic floor and then re-insulate (in most cases, we would first remove existing insulation).

But this only works if there’s no mechanical equipment (and ideally no storage). If the attic is used for anything other than insulation, best practice is to bring the attic space indoors, either by insulating the underside of the roof sheathing with spray foam or by removing the roofing, insulating the topside of the roof sheathing with rigid foam and then re-roofing.

If the roof needs to be replaced, “outsulation” might initially seem viable. But I can count on one hand the times we have actually done it. More often than not, it’s doomed by cost or adverse architectural consequences. This is why spray foam has long been our go-to approach for unconditioned attics with HVAC equipment.

New Approaches for Lower Carbon

At least it was until we realized just how carbon-intensive it is. We came to this realization by comparing the embodied emissions of spray foam against four alternatives. We based these comparisons on a simple gable-roof form. The four alternatives we looked at were: 

* A low-foam approach of building down the rafter bays, insulating with closed-cell foam for condensation control, followed by cellulose behind a smart membrane.

* A no-foam approach where the air and thermal boundary remains at the attic floor. We install the air handler in a conditioned “head house” and bury the ductwork in cellulose. 

* A common outsulation approach with cellulose in the rafter bays plus exterior polyisocyanurate board foam.

* A newer, no-foam outsulation approach with cellulose in the rafter bays plus exterior wood fiber board.                                                                                                                                                                                          All of these approaches, including exterior polyisocyanurate, are either carbon neutral or carbon storing from the outset. Only spray foam starts off in carbon debt.

This chart shows the embodied carbon of several options for insulating the attic floor or the roof. Chart courtesy Byggmeister.

What we call the “low foam” approach includes 3 inches of closed-cell spray foam on the underside of the roof deck plus 8 inches of cellulose and a membrane to control moisture. Illustration courtesy Byggmeister.

And this debt is not small. Our modeling suggests this particular measure would take 14 years of operational carbon savings to break even. Even if our model isn’t exact, it’s close enough to know that spray foam should not be our default approach if there are viable, lower emitting alternatives.

In Two Carbon Smart Ideas for the Attic, we walk through the no-foam, head house approach in detail. We also describe our efforts to develop a carbon-smart approach to another common attic/roof condition: poorly insulated, finished slopes. When such slopes are topped by a “micro attic,” we are experimenting with dense-packing the slopes, installing loose-fill cellulose along the floor of the micro-attic, and adding a ridge vent.

We Must Take Risks

Both of these approaches seemed impractical when we first took them on. Both present some level of risk. Because of code constraints, the second one may not be broadly replicable even if we can demonstrate that the risk is manageable. But if we are going to cut global carbon emissions in half by 2030 and get to zero by 2050, we’ll have to take some risks and pursue approaches that aren’t (yet) standard practice. By sharing our story, we hope to inspire more of our colleagues to join in this effort.

Rachel White is the CEO of Byggmeister, a design-build remodeling firm in Newton, Mass. This article was first published in Green Building Advisor.

 

 

 

 

Reference