Wooden office interior with Kerto-Q LVL panels
 
All images of One Main by dECOi Architects, Director Mark Goulthorpe, Project Architect Raphael Crespin.

One Main office

Location USA
Building Year 2010
Architect dECOi Architects
Products Used Kerto LVL

 

Wooden interior design shows the astounding possibilities of Kerto LVL

Designing and constructing the wooden interior for the One Main renovation project in Boston, USA is a showcase for an untypical use of Kerto® LVL (laminated veneer lumber). The wavy wooden surfaces that comprise the interior are built entirely from cross-bonded Kerto® LVL panels  that are usually used in structural members.

Wooden interior design for One Main office 
 

The project’s principal architect, Mark Goulthorpe from dECOi Architects, a professor at nearby MIT, offered a proposal with a greatly streamlined building methodology, where the usual multi-trade, multi-component legacy of late-industrial production was surpassed in a unitary CAD-CAM logic.

Kerto® LVL for wooden interiors

Technical advantages and availability led to the choice of Kerto® LVL

Metsä Wood’s cross-bonded Kerto-Q LVL is typically used in structural elements. However, the One Main office in Boston is an excellent example of a completely different way to use the product.

Kerto-Q LVL got the nod from dECOi Architects due to its thickness and because it comes in big panels. Kerto is relatively inexpensive, relatively gap-free, and has no long waiting period. It was a pragmatic choice to balance costs, fabrication and aesthetics. The greatest benefits of Kerto LVL are that its raw material is sustainably grown, and that as a large, laminated panel, it readily lends itself to milling that yields a good, strong edge. Given the laminated mass, it can look extremely seductive. If dECOi had reduced the thickness of the laminates, or the panel size, the milling time and cost would have increased exponentially.

Prefabrication speeds up the assembly

Large, highly-accurate prefabricated parts minimized labor on-site

Every part of the interior was fabricated off-site with a powerful three-axis CNC machine. The design algorithms divided up the architectural forms into discrete elements that could nestle onto 12 ft × 4 ft (3.7 m × 1.2 m) panels, all automated and optimized by the architectural team. The parts were milled with dowel holes so they could be easily located spatially without requiring much other than sequencing correctly, alignment, and gluing or nailing.

The goal was to minimize labour on-site, and to a large degree this was achieved, as larger and larger finished parts were delivered to site – for example, entire office floors or the reception desk shipped as completed elements that only needed to be positioned on-site.

Since all the elements were milled, the integration of secondary elements such as lights or ventilation was very simple, literally milled into the woodwork - the lights just dropped into pockets in the wood, the vents or sprinkler heads attached with a simple screw.

Wooden dowels for connections

Wooden interior design - wooden dowels for connections 
 

Functional wooden ceiling suspending from the roof slab

The functional office space is “trapped” between two active surfaces – the floor and ceiling – which are each “animated” by functional attributes such as vents or light housings. The base spatial arrangement is established by the reception desk seeming to rise out of the floor, or by the ceiling being “pulled” down towards the floor for structure, or up to the sky for light.

The narrow wooden pieces were connected with wooden dowels, water-based glue and a nail-gun to attach the parts into laminated elements. This proved to be a quick and easy way to assemble what seem complex parts. The elements were then hand-sanded and sprayed with a matt, water-based varnish. The existing office tower was a 1970s concrete slab building with hermetically sealed windows and full air conditioning. There was plenty of structural redundancy to hang the relatively lightweight ceiling panels from the roof slab.

Glued connections for Kerto-Q LVL panels
Glued connections

The parts were milled with dowel holes so they could be easily aligned. The narrow wooden pieces were connected with wooden dowels, water-based glue and a nail-gun to attach the parts into laminated elements.

Suspended ceiling with Kerto-Q LVL panels
Suspended ceiling
The suspended ceiling is hanging from the roof slab with steel cables. There was plenty of structural redundancy to hang the quite lightweight ceiling panels from the roof slab.

Kerto-Q LVL panels
Kerto-Q LVL panels

​Every part for the One Main interior was fabricated off-site by a small mill working company with one powerful 3-axis CNC machine. Flat Kerto-Q panels turned into compex, curved, 3-dimensional shapes.

Curved shapes from flat Kerto® LVL panels

Streamlined fabrication process with a single 3-axis CNC machine 

It was imperative to streamline the actual milling process for speed and economy. All the visible elements of the design were fabricated as stacked sectional elements cut from flat Kerto® LVL panels.
The ceilings, walls, floors and static furniture were all created as striated elements made from layers of Kerto® LVL, with functional elements such as ventilation grilles, light pockets and door handles formed by directly milling the wood.

The architects handed over actual milling files – the actual cutting instructions – for fabrication, with the elements already mounted on some 1,200 Kerto® LVL panels to minimize waste. The instructions were then issued digitally to the numeric command machine.

Well over one million linear feet of cut were issued, a shift in the base protocol of contracting logic, the architects fully in control of every detail via the fabrication code.

Fire safety with Kerto® LVL interiors

Fire safety with wooden interiors 
 

The wooden design of One Main could likely have gained fire approval for the ceiling given the size of the members, which char and resist decomposition, but in the interests of expediency the architects ended up double-sprinkling the entire space – one layer of sprinklers at the slab above the ceiling and one projecting through the ceiling.

The sprinklers are attached to milled pockets that hold them normal (90 degrees) to the surface of the ceiling - this is what is specified for fire stairs (the sprinklers turning with the diagonal flight of stairs above) so that the plume of water is unimpeded.

Carbon absorbing building material

Wood – carbon absorbing building material 
 

Wood for Kerto® LVL comes from sustainably managed forests

In a material sense, the One Main project assumes a radical environmental agenda, using a sustainable and carbon-absorbing raw material, translated efficiently into refined and functional elements via dexterous low-energy digital tooling.

Spruce is a fast-growing softwood, and all the raw material for Kerto® LVL comes from sustainably managed Finnish forests. The carbon sequestered by the tree growth exceeds by far the carbon released by the energy consumption of transport and fabrication, since the cutting and assembly use lightweight, efficient machines.

Quick facts

 

  • One Main uses sustainably forested Finnish Kerto-Q LVL with non-toxic water-based glue. 
  • The 10,000sq ft (1000m2) project nested onto 1200 sheets of 1.5” thick 4ft x 12ft (3,7 m x 1,2 m).
  • All the parts were milled locally by a single 3-axis milling machine. 
  • dECOi provided the actual tooling paths (over 1 million linear feet of cut) in 3D instructional files. 
  • Wastage was about 10%, pulped and recycled.

All reference  cases

  • FMO Tapiola – wooden office building

  • One Main office

  • Hurlingham Racquet Centre

  • Herbert Art Gallery glulam facade

  • Viikki wooden apartment buildings

  • DB Schenker wooden terminal building

  • Skanssi - Stark department store

  • Mega Market commercial building

  • Metsätapiola - wooden office building

  • Aylesbury Waterside Theatre

  • Tommi Mäkinen Racing building

  • My Green World exhibition centre

  • Aurajokiranta apartment building

  • Edinburgh Center for Carbon Innovation

  • Metropol Parasol - one of the world’s largest wooden buildings

  • Tesco grocery store

  • Kannustalo ready-to-move houses

  • Daycare Omenapuisto

  • Karisma shopping centre

  • Diesel Benelux headquarters

  • Agricultural building, Koski Manor

  • Ämmässuo construction-waste handling plant

  • Kerteminde children’s home

  • Paris police department - wooden extension

  • Immanuel Kirche - wooden structure that impresses

  • Straagaarden using nature's own resources

  • Cinema De Roma – thoroughly renovated

  • Kaifu-bad – oldest spa in Hamburg

  • Schlagwerk – hall for producing musical instruments

  • Berlin-Britz – open air stage

  • Le Pavillion wooden office building

  • De Karel Doorman – 16 floors extension

  • Rakuunantie extention storey

  • Cockfield Windmill – conversion to accommodation using Kerto® LVL

  • Extension to a building in Paris

  • Clamart Sport Centre

  • Östermalm’s temporary market hall

  • Dutch Stay Okay hostel

Search all references