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Project Name: MIRA SF / Clementina Alley

Firm: INTERSTICE Architects

Project Designers: Zoee Astrachan, RLA, Principal & Andrew Dunbar, Principal; Shye Jones, Designer; Rebecca Bartlett, Designer



INTERSTICE began our involvement with this project in the start of 2015, and from the beginning the complex – Transbay Block 1, now MIRA SF – was imagined as a key urban ecological linkage in the context of the transformation of the Transbay neighborhood, from transit infrastructure to community. Working in collaboration with Studio Gang’s team and inspired by the dynamic architectural expression of the rotated bay window of this new vertical neighborhood, we shaped the landscape around a set of avian metaphors and critical aspirations to balance human development. Paramount was the desire to create a built environment that provides amenity to humans and ecological benefit for non-human species. The shared design language between the building and the landscape includes an authenticity of materials, a focus on sculpture, texture and tactility, and an angular and faceted yet, non-orthogonal geometry. The landscape design creates a vibrant, urban environment characteristic of downtown San Francisco, encompassing contrasts – colorful and comforting, timeless and contemporary, diverse and simple, durable and tactile. The ecological triumphs of the project include its reuse of grey water resources to irrigate the landscape, and the design of diverse plant palettes that support the native avian and insect populations that are vital to the ecology of a livable urban natural environment. This city block spirals upwards as a densely designed vertical neighborhood of some 400 homes for humans, equivalent to 16 city blocks of single-family homes in a typical city, and sponsoring an critical and opportunistic 5th façade as carefully designed roofscapes that support habitat.

Clementina and Streetscape

INTERSTICE’s design efforts focused on creating a vibrant streetscape as part of the Transbay Streetscape Masterplan, an important piece of making this a walkable, livable and intimate-scaled neighborhood experience at the foot of this very tall tower building.

The streetscape design was guided by two important design elements – the Transbay Streetscape & Open Space Plan, crafted in 2006, and the development of the Folsom Street Improvement plan, conceiving of Folsom as pedestrian-prioritized boulevard with tree-lined widened sidewalks, commercial activity, rain gardens, seating, bike lanes and other safety and amenity improvements.

The new Clementina Alleyway POPOS is an unusual opportunity to create an intimately scaled slow, shared street connecting this new vertical neighborhood to the Embarcadero, the future Transbay Park and the extension of Clementina through the neighborhood as part of a network of alley ways that characterize the Transbay and SOMA neighborhood. Clementina, as the front stoop to new townhomes, is a green, plant-lined corridor that widens to the east, where the lane becomes the Clementina Commons over top of the parking garden entry – an intimate open space with seating for people and their pets, an opportunity to connect with the greater neighborhood, and a venue for block party gatherings. The street right of way is an intimate 34 feet across providing our team with challenges around emergency access and creating a planting environment for trees. The features that unify Clementina with the other blocks include the rhythm and hue of the banded pre-cast pavement, the columnar gingko tree plantings, and the pedestrian pole lights, in addition to the raised stoop townhouse entries. The design of a soil cell pavement support system helps to ensure the growing space for tree roots in this tight urban space.

Folsom, Main and Spear streets with their widened sidewalks, with contrasting granite bands, dynamic pre-cast street furnishings complete a pedestrian focused environment as a promenade for residents to linger at the new commercial ground floor shops and restaurants. On Spear Street raised garden planters provide additional informal perch seating and broader planting areas for trees and understory. On all frontages a soil cell pavement support system expands the root zone significantly to ensure the health and longevity of the street trees.

Roofscapes and Amenity Terraces

The multiple roof tops are landscapes of elevated grounds, all vegetated for residents to enjoy, and as a shared resource with the native ecology of the Bay Area – including purposeful seasonality, prioritized natives, species diversity, ground habitat, and water reuse – as all plants are watered by reclaimed grey water generated by the residents’ showers and stored in large tanks in the lower level garage, with storage potential for almost 5,000 gallons used to irrigate through California’s long dry summer and fall seasons.

The level 2 podium courtyard that is accessed from both Main Street and the Folsom Street Tribune Stair is an unusually patterned and architectural textured space that supports a wood land grove of white barked birch trees and provides daylight into the building’s gymnasium below through three large lantern-like sky lights. The other surrounding plantings include ferns and woodland natives acclimated to the shady courtyard space.

There is over 54,000 square feet (over a 1 acre) of open space on 5 levels, including two vegetated roofs one intensive and one extensive. The design includes native plant species and habitat for native hummingbirds and insect populations through careful species selection as food and nesting sources, and includes elements on the uppermost roofs that serve as micro-habitat, in the form of dozens of natural logs embedded in the living roofs, that provide cover, homes and organic matter as they naturally decompose over time.

Features include:

  • Open space: 54,000 sq ft on five levels
  • 8,600 sq ft of vegetated roof: 16 different Sedums + 16 Species of Perennials and Grasses
  • > 100 Diverse Plant Species – 40 Native Species – 8 Tree Species
  • Focus on native hummingbird food and nesting species
  • 30 Douglas Fir logs that act as planting dividers visually and serve to create micro-habitat for birds and insect residents
  • 6,000 Cu Ft of Soil for podium level Birch “Nest”
  • 4,800 Gallons of Storage for Shower Water to Irrigate Plantings
  • 15,000 Cu Ft of Planting Soil Below Sidewalks for Street Trees
  • Achieved LEED Gold