For more information about the GreenStaxx Building System, go to

GreenStaxx uniquely integrates the quality and speed of pre-engineered units, the power and data organization of BIM (Revit), and the flexibility and ease of units pre-designed to fit perfectly together. The patented GreenStaxx system consists of computer-based libraries of three-dimensional unit stacks that are sustainably engineered, market tested and designed to the last doorknob.

Like toy blocks, GreenStaxx virtually models and assembles building parts onto sites of varying sizes and shapes. Each part is a stack of residential units completely specified, designed, engineered and 3D modeled. The collection of these parts form a library of unit types including outside corners, inside corners, units with stairs, a unit with an elevator shaft, one bedroom units, two bedroom units, etc. This library of unit types provides the data and documentation to quickly and easily design, evaluate, estimate and construct high quality, energy-efficient multi-family residences.

The GreenStaxx system has been used in both modular and traditional timber frame multi-family, residential and mixed-use projects ranging from 35 - 280 units. GreenStaxx is now focused on the symbiotic advantages that modular construction provides in combination with the GreenStaxx system, particularly in urban, mixed-use or multi-family residential projects.

right hand image

Simultaneous site preparation and modular fabrication compresses construction time. 30 Haven's 108 boxes were set in 3 1/2 weeks.

right hand image

30 Haven, Reading MA includes fifty-three one-and two-bedroom homes and 22,000 SF of retail space on the ground level.


This process-system is patented by GreenStaxx in the United States. The patent protects the process of marketing a design/build system based on stacked units in a computer interface to multifamily developers. Stacked units are pre-designed and pre-engineered and independent of a specific project. When a project is identified, a grid is created to fit local conditions and sized to fit the unit stacks. When units are placed into the grid, the result is a completely integrated set of contract documents that are connected to supply chains, including modular manufacturers.


Utilizing GreenStaxx, teams at the local level, site owners and developers can quickly and accurately evaluate sites, generate entitlement and construction drawings, and decrease construction time while maximizing building potential and quality.


The GreenStaxx system has an exceptional ability to accommodate a variety of sites.

Modular Construction

While the use of modules or boxes is relatively new to multi-family construction, Oaktree's GreenStaxx system has been under development for many years resulting in a high quality product that adapts especially well to smart growth, in fill, urban and urban-suburban projects.

GreenStaxx provides a high quality, cost effective, green product that is faster to build because it is easier to site, price and coordinate. GreenStaxx utilizes a library of 20 units that can be virtually stacked and assembled onto a grid like toy blocks to accommodate a site of any size and shape. Iterative in nature, the GreenStaxx system is pre-designed and pre-engineered to address and refine the complex integration of materials and mechanical systems. The result is greatly reduced risk, much better coordination and a consistent, energy efficient, well-constructed product.

Modular Projects

Cambridge Cohousing in Cambridge MA is a modular 41 unit condominium project located near Porter Square. Completed in 1997, Cambridge Cohousing includes a variety of unit sizes and configurations: large townhouses, small townhouses and flats configured as studios, one, two, three and four bedroom units. In 1998 the AIA chose Cambridge Cohousing as one of the 10 best examples of sustainable residential design in the United States.

30 Haven in Reading MA is a mixed use residential project with 53 one-and two-bedroom homes and 22,000 SF of retail space. Built to the highest energy-efficient standards, 30 Haven's apartments have high ceilings, stainless steel EnergyStar appliances, wood cabinetry and granite counters. Building residents enjoy assigned garage parking, fitness room, guest room for visitors and a community living room with fireplace and full kitchen.

Chelsea Place in Chelsea MA is a boutique apartment community of 56 one and two bedroom apartments located just 5 miles from downtown Boston. Located near shopping, dining and entertainment and adjacent to Mill Creek Park, Chelsea Place is close to multiple MBTA bus lines and walking distance to the MBTA Commuter Rail Chelsea Station. Chelsea Place meets LEED Silver certification standards for new mid-rise construction.

Newtonville Square was designed by Austin Street Partners, a partnership of Oaktree and Dinosaur Capital in response to an RFP from the City of Newton. Still in the design phase, Newtonville Square's goal is to contribute to the City's vision for a vibrant, sustainable and transit-oriented community in the Village of Newtonville.

Traditional Construction

The GreenStaxx system and library of units have the flexibility to be applied to traditional construction when conditions are not well-suited to factory produced modules.

7 Cameron in Cambridge MA is wood panel construction using the GreenStaxx system. 7 Cameron has 37 residential units and is adjacent to the linear park/Bike Path, a popular commuting alternative to cars.

Brookside Square in West Concord MA is wood panel construction utilizing the GreenStaxx system with 74 units on two floors above 38,000 SF of commercial space and steps from the MBTA commuter rail.

Saint James Place in Cambridge MA originated as a collaboration between Oaktree and the congregation of St. James Episcopal Church to create a green, transit-oriented, walkable project with apartments, retail space, parish house space, garage parking, exercise room, function room, common roof deck and an open landscaped courtyard.

Urban, mixed-use

Oaktree believes that good housing embodies a high quality of life and a high standard of living at an affordable price. While the purchase price or rent is a critical element of this equation, the addition of smart growth principles creates additional conditions to address the cost of living, the carbon foot print and the role of housing in the economic and social fabric of a community. Access to public transit reduces the use of cars. Walkability increases exercise contributing to better physical and mental health. The choice of housing encourages a mix of generations. The combination of retail and residential with convenient vendors and on-site customers increases economic activity and viability. For the average household, this translates into reduced transportation and health costs.

As a 40R mixed-use, multi-family apartment community located one half block from the commuter rail and a short walk to Reading's revitalized Town Center, 30 Haven is well-positioned as a retail and residential hub to attract commuters, pedestrians and cyclists.

Inspired by its location next to an extensive network of paths through conservation land leading to the Assabet River, Brookside Square's contribution to environmental sustainability includes drought resistant plantings, solar panels and pathways for pedestrian access to the surrounding natural landscape, commuter rail and shops.

Newtonville Square was designed by Austin Street Partners, a partnership of Oaktree and Dinosaur Capital in response to an RFP from the City of Newton. Still in the design phase, Newtonville Square's goal is to contribute to the City's vision for a vibrant, sustainable and transit-oriented community in the Village of Newtonville.