卡鲁纳楼的混凝土上发泡：被动式房屋的创新和简单|锤和手

照片记录锤和手的直接的方法，以被动式房屋建筑的前沿方面。

其中最引人注目的方面被动式房屋建筑是强调简洁。标准本身很简单：达到节能性能要求的水平，你的建筑可以证明。

并通过被动式房屋设计师和建设者使用的手段很简单，太：superinsulate，打造密不透风，避免热桥，用优良的门窗，通风机械与热回收通风，并优化通过智能定位和设计，太阳能和热能的收益。

The vanguard of 21st Century building is not about complex technology.

This illustration by the Boston firm Albert, Righter and Tittman Architects makes the point nicely.  We’ve moved beyond a bunch of gadgetry and expensive mechanicals:

What’s sophisticated about Passive House is the advanced building science that underpins it, enabling us to take simple strategies and, with the help of powerful modeling software, combine them into designs that achieves revolutionary energy savings at optimized cost.  It’s this deep understanding of buildings that allows us to move past the “20th Century” approach at the center of the illustration above.

So, there’s nothing simplistic about Passive House.  But, consistent with principles of good design that date back to the Renaissance, the standard allows us to design and build elegantly simple, high performance structures.

The Karuna House isn’t just pursuing Passive House certification, but also LEED for Homes Platinum and Minergie-P-ECO.  (See this Field Notes post about the three certifications.) But this drive for simplicity permeates the project team’s work, both by Holst Architecture at the design table and Hammer & Hand on the construction site.

“What we’re finding as we build Karuna,” Lead Carpenter Scott Gunter told me, “is that while we’re definitely doing ‘outside the box’ stuff out there, we’re drawing on straight-forward, time-tested construction techniques to make them happen.”

A case in point: in our last video installment about Karuna, Scott demonstrated how his team installed a layer of geofoam insulation that the future house will sit on.  That’s certainly “outside the box” stuff.  Not a lot of buildings have their foundations poured on top of a foot-thick layer of expanded polystyrene.  (Yet.)  But the basic techniques employed to accomplish the job – batter boards, plumb lines, leveling, screeding, compacting – would be familiar to any field carpenter.

Hammer & Hand’s Aaron Bergeson and Scott Gunter carrying the EPS foam used to insulate Karuna’s underslab.

The same is also true for forming and pouring the foundation.  Granted, in this case the foundation was poured on top of EPS geofoam, but Scott and his team used box form and plywood construction to do the job, standard practices taken directly from the production concrete playbook.  So while we’re doing cutting-edge construction at Karuna, we hew to simple techniques whenever we can because they’re fast, cost-effective and proven.

A word about the concrete: in keeping with LEED and Minergie-ECO requirements, we’re using concrete made with a 30% fly ash mix and locally-sourced aggregate.  Fly ash is a byproduct of coal combustion and can substitute for a portion of the Portland cement content of concrete.  Given the high carbon emissions required to produce Portland cement, substituting with fly ash helps reduce the ecological footprint of concrete.  Plus it diverts fly ash from landfills and reduces demand for the virgin materials that make up Portland cement.

Now on to the site photos.  In addition to playing a key role in coordinating our team at Karuna, Hammer & Hand’s Shelley Martin is documenting construction progress on site.  Scroll on for her photos and Scott’s notes…

Installation of the geofoam insulation under the footings is underway.

Here we see the formwork for the footings – standard box form construction.

Another view of the formwork for the footings.

In this shot the footings have been poured and a black capillary break material has been installed.  Concrete likes to wick up water, so this capillary break will keep moisture from coming up through the footing and transferring into the stem wall and up into the floor slab.  The blue material is the vapor barrier tied into the underslab insulation.

This shot shows a broader view of the footings with the black capillary break installed on top.

Here we see how the footings sit on top of a thick layer of EPS geofoam.  (See this video for detail about the process.)

This shot shows formwork for the foundation walls using standard plywood and box form construction.

Here the footing and wall pour is complete, with concrete that has a 30% fly ash blend with local aggregate.  The next step will be to roll on the waterproof air barrier, an emulsion made specifically for “green” (ie. not-yet-cured) concrete.  We were able to apply the waterproof air barrier just 24 hours after stripping the forms – a nice timesaver.

Here we see the footings and wall casts.  As you can see, we’ve rolled the EPS foam up and around the footing and have applied the waterproofing to both the top of the footings and the stem wall.

Aaron Quint examines the underslab insulation, 12” of EPS geofoam laid on a compacted gravel bed.

另一个拍摄underslab绝缘，接近完成。

在这里，15毫米的空气和水汽阻隔的接缝都被录音。在右边，注意在基本的黑条。这是一个?“厚厚的一层可压缩毡将作为伸缩缝，使混凝土的运动。

保持这个星期调整为新的视频。船员们一直忙！

- 扎克

返回现场注意事项