What’s behind proposed ‘green factor’ zoning? Q&A with co-authors make some issues clear
With extreme high temperatures and flooding expected to be increasingly common in the Cambridge of the near future, residents Mike Nakagawa and Doug Brown bring their “green factor” zoning back this week to the Planning Board (at 6:30 p.m. Tuesday) and to the City Council’s Ordinance Committee (at 5:30 p.m. Wednesday) for an intensive look by city officials.
When the proposed zoning was introduced at a council meeting in April, a lot of comment expressed worry it would slow the construction of housing or decrease the number of units built – something that would draw plenty of opposition at a time people continue to be squeezed out of the city by a lack of housing options, especially affordable ones. Indeed, the residents group A Better Cambridge stated its opposition Monday in a summary and detailed response, despite saying much of what’s proposed “deserves serious consideration.”
In 2013, the group opposed the city’s net-zero emissions rules but said doing policy “right” would include “reducing urban heat island effect by implementing zoning and building codes that allow for more cool roofs, green roofs, and urban landscape strategies.”
Nakagawa and Brown say their plan focuses largely on awarding each large, private project a “green score” to encourage developers to build in ways that will help the city when extreme heat days and flooding proliferate. The higher the score, the more steps have been taken: trees, green roofs and other permeable open space planted – because nature handles flooding better and keeps us cool – as well as structures where amenities are raised above worst-case flood levels and thought has gone into keeping residents safe.
The zoning authors sat down in May to talk through some of these issues. The conversation has been edited and condensed significantly for publication.
Why the zoning
Mike Nakagawa: The city created a preparedness resilience plan for Alewife and came up with strategies, and the area that we as citizens can have impact in is zoning – and we’re taking what they’re saying we should do. We’re not trying to do everything, though. This is not the Envision process. We’re not saying what you build or how much or what type of building, just that if you’re going to build something, make sure it’s safe and promoting the health of the people occupying the building and the health of the people who will be affected around it. You don’t want to flood the neighbors, and you don’t want to make it hotter.
Doug Brown: We’re really talking about the quality of what’s built. How you actually use a given site to help with flooding and to anticipate heat. Are things elevated? Are they protected from floodwaters?
Mike Nakagawa: Is there a way to get to the buildings in an emergency and can people get out if they need help?
Doug Brown: Much of what we propose came out of city planning documents.
Mike Nakagawa: And other municipalities and other agencies. We didn’t just make these up.
Doug Brown: Right. We looked at what does the Environmental Protection Agency say, what does the Federal Emergency Management Agency say, what does the Army Corps of Engineers say, what do other researchers say?
Doug Brown: The second piece is that the floodplain is getting bigger. If we know what it’s going to look like in 2070 – and we have pretty conservative estimates – we should probably think about how we build in those areas now. Because these buildings will still be there in 2070. And that gives you 50 years rather than starting to try to retrofit everything when the water’s here.
Shape of the problem
Doug Brown: One of the problems is that at the point the worst effects of climate change kick in, you live with whatever you’ve built, and the ability to change over time is relatively slow. Not very much of our housing stock gets replaced in a given year, so you really can’t wait until you see the problem happening to start to adjust to the problem.
Mike Nakagawa: Buildings last for 50 years.
Doug Brown: Fifty to 100 years.
Cambridge Day: Are we already starting to plant trees and other plants that will be resilient enough when the extreme heat starts?
Mike Nakagawa: We haven’t looked into [what to plant]. The main thing we’re trying to address is having space for them. And if you don’t set up the infrastructure – like, once you put a building across your property, there’s no trees going there for the next decade.
Doug Brown: And we’re actually losing our tree canopy, not gaining on the problem. It’s unlikely that what we’re permitting currently will address these issues. For example, 50 Cambridgepark Drive, which is being proposed now, if you look at the site plan, has 20 trees. If you went out there today and counted trees, you’d find 25. Both of those are very low numbers. But we’re not making a dent in any of this. And it’s unlikely we will under the current rules.
Doug Brown: The only real rule the Conservation Commission enforces is that a project has to be better than what was there before. A smart developer would pave over everything they owned, because in effect this gives you a license to do almost anything you want, because you’re always going to make it better. The question is, how does that compare with what you could do or what land was like naturally?
If the commission were to ask for further accommodations, it’s at their peril. If they ask for too much, the developer can go back to the state and say “They’re holding me to a standard that you don’t have, throw the whole thing out,” and the city can get overruled by the state. So the Conservation Commission is trying to negotiate, but they’re relatively hand-tied in what they can ask for.
Mike Nakagawa: For a long time there was this series of appeals where the state would come back and take away all the extras, and we said, “Okay, we’re going to stop asking for extras.”
The Planning Board get asked if developers are meeting the overlay district requirements and says, “We don’t know environment, that’s the Conservation Commission.” The commission says, “Well, what does engineering say?” And engineering says “It’s all good to us, because we want more development.”
Doug Brown: You need to build in a certain element of safety when you’re doing engineering, right? If we don’t know how bad it’s going to be in 70 years, I don’t think the answer is well, then we should just study it more now until we have a good answer. What we’re debating is whether the sea’s going to go up 3 feet or 10 feet. Those are both a big problem for us.
Mike Nakagawa: How well your solution works depends on how well the assumptions match reality. FEMA rules on flooding were based on the assumption the climate wasn’t changing, but we know things are.
Doug Brown: MIT is doing a resilience study, and their projections are worse than ours. Somerville has also done a study of a dam we say is good until 2045, and they say 2035. We find we’re using a relatively conservative estimate for how bad it’s going to be. But prudence would dictate that’s not always the best way to go.
Scoring the green factor
Doug Brown: Because heat is citywide, there’s the idea of a green factor, which is really a way of scoring land use and landscaping to reflect things we want to encourage: trees, green space, permeable area that will hold water and are cooler. It’s a relatively simple system. It’s in use in Seattle and Washington, D.C. Somerville has it in a version of their code that they’re working through now.
Mike Nakagawa: Berlin’s been doing this since the 1990s, where each project gets a score. Like, a tree is worth something.
Doug Brown: A big tree is better than a little tree.
Mike Nakagawa: A preserved tree is better than putting a new one in. If you have one 18-inch diameter tree on your site, that’s worth 40 times one of these new trees. So there’s a value in trying to preserve those, because it takes a long time to grow a tree. I have some of the biggest trees in the neighborhood in my tiny backyard and I can vouch for the 10-degree cooler thing. In the summer, we rarely use the air conditioner. We get home and open the windows and in 20 minutes we’re good.
Doug Brown: Where you what to encourage one use over another, you can raise the score a little bit, but the nice thing about it is that it’s not prescriptive. Whereas traditionally we say “Height equals 100 feet, that’s the limit,” this basically allows you to say, “Look at your site and decide what’s best for you.” If you decide you want to do a green roof, or a green wall, then you can have a little less space on the ground. You have the ability to adjust the factors.
Cambridge Day: How do you feel about Somerville’s proposed green factor formula? Could Cambridge adopt it wholesale so there’s a consistent regional approach?
Doug Brown: Different cities have slightly different criteria and give different scores. In Somerville there’s a lot of similarity. There are some things we want to be more clear about – they’re a little vague around trees, for example.
Mike Nakagawa: They say a small tree is worth this and a big tree is worth that, and I’m like, well, what’s a small tree and a big tree? But Seattle and D.C. in particular have pages and pages of details.
Doug Brown: Mostly we’re talking about larger buildings, and every large building that’s proposed already has a landscape architect and a landscape plan, which makes it relatively simple for them to calculate a green factor. In terms of it being a burden on them, within a floodplain we’re asking for a minimum score, and in some cases, these developers are already doing what they should be doing. Across the city, we’re just asking them to tell us the score. There’s places across the city where we want more information because over time we want to be able to see current conditions. To adjust those factors, we can adjust the requirements.
We met with Homeowners Rehab Inc., which has a project in the Alewife Quadrangle for 99 units of affordable housing. Our interpretation was that they are exempt from this zoning. We think it’s most likely we would try to work out language that exempts a project from a nonprofit doing 100 percent affordable – they have certain financial challenges, and in many cases they’re meeting a lot of the spirit of this.
Mike Nakagawa: If we feel 100 percent affordable projects are a benefit to the city, maybe the city can support some of these green infrastructure goals and help them along, because they don’t have a lot of margin to work with. Maybe we have to be thinking about an escrow, where these are definite impacts we need to be preparing for.
Doug Brown: There was very much a generality this will hurt development, this will hurt housing, but those objections weren’t grounded in anything other than the idea that more requirements will make those things more difficult and more expensive. And on the face of it, that might be a logical thing, but there is this question of having to invest to prepare.
Mike Nakagawa: There are some initial upfront costs, but we will reap the benefits as a community over time.
Doug Brown: And it’s the right thing to do. This wasn’t laid out as a way to defeat projects or to reduce housing. Those just don’t make any sense to us. We don’t like what’s out there right now anymore than anybody else does – it’s vacant parking lots and not a terribly nice place to be, in many cases. and development is the tool by which you fix those problems. This isn’t a moratorium. This is an effort to influence and shape what we build so we get the outcome we want.
Mike Nakagawa: Another thing we heard was about the unknown cost. There will be some cost, but it’s all speculation that this will be too burdensome.
Doug Brown: We didn’t set out to make this onerous, we set out to make it relatively easy for developers to say, “let’s do that.” Do added requirements have an impact on housing? Do any of these things make it harder or more expensive to build housing? There are more requirements, so the answer may be yes. But is that a problem such that no one builds any more housing ever again? Or that what we do build is better? We need to be able to tell a story that this is not an onerous burden if you’re doing it now. That said, it needs to be taken into account that two-thirds of the anticipated construction in the quad is commercial, not residential.
Mike Nakagawa: Does it cost more to build green infrastructure? Of course, but we’re trying to add value. You have to look at this as an investment in the future.
Doug Brown: FEMA says every dollar you spend now saves you $6 later. In the life of one of these buildings, you might save that on cooling costs alone. Most of the energy use now is heating, but we’re crossing the line where going forward most will be cooling.
Mike Nakagawa: There are also things like emergency preparedness, where if it’s cooler you don’t need to transport people to the hospital from heat stroke.
Doug Brown: There’s an element of investment, and you could say the same thing about building codes, which cost more than not following building codes. There’s a reason for that.
Mike Nakagawa: For health and safety there’s a cost. We have things like firewalls because you don’t want a fire to transfer to the next building, but there’s a tangible benefit. Most of the safety code things are hidden or you wish they were hidden –
Doug Brown: – meaning they’re only relevant when you’re having an emergency. When the house is on fire, then you’re glad you have those things.
Mike Nakagawa: Also, a recent study shows that if you invest now you get three times back in general economic benefits.
Doug Brown: Moody’s issued a report saying that going forward when they evaluate bond ratings, they’re going to consider risks from climate change. If you have a serious risk of climate impacts, that will play into your bond rating. In some ways, this allows the city to say, “Look, we’re doing everything we can here to ameliorate those risks.”