Variation of modes of use: functions, users, schedules, etc.

Relationship between the ownership and the form of the investment that allows the transformation

Variation of the overall dimensions of the building

Proportional relationship between new spaces and existing spaces

Relationship between the structural adjustments and the existing structure

Relationship between the forms and types of pre-existing materials and those of the new intervention

Relationship between the image of the new and the image of the existing (mimesis / contrast)


Milan, Italy


Luigi Ferrario Architettura



Luigi Ferrario – Casa 25

PROJECT - Main Infos

PROJECT: Luigi Ferrario – Casa 25

LOCATION: Milan, Italy

YEAR: 2018

ARCHITECT / FIRM: Luigi Ferrario Architettura

BUYER: Luigi Ferrario

SURFACE: 100 sqm

PRICE: € 400.000

Casa 25 is the refurbishment of an old portico along a ditch in Milan. The portico was part of a wine store in the backyard of a 19th century building of five stories and two lower wings. Documents from 1899 show the brick and wood portico built along Castello ditch as a facility to shipping and receive barrels of wine. The ditch was covered in 1976 and in 1999, one century later, the portico was purchased, a little more than a ruin hidden behind large advertisement billboards facing the busy street; only the perimetral walls were standing. The following year the first phase of the restoration began, an open space house and atelier was built inside the original masonry perimeter and the billboards were removed from the façade. The interiors were arranged as an unique space: it contains a sequence of the architecture studio, living area and kitchen, with storage units on wheel and curtain as mobile partitions. A second inner level was added on a metal structure mezzanine for the bedroom with bathroom and a library on the opposite side of the house, linked by a glass walkway. The structure that support the roof use metal beams as well. A fence enclosed a rectangular space between the house and the street. In 2014 new courtyard and fences were designed to make the outside space more liveable. The brand new Corten fence enclose a courtyard with lush vegetation, fountains and aquatic plants. In the meanwhile, a design to vertically expand the house was envisioned. The new refurbishment will be completed with a new volume, realized with a metal structure leaning on the existing walls and roof, that will host the new house while the existing one will be serving hosts visiting the owners. Nowadays the metal frame are waiting for the new house, in the meanwhile they supports climbing plants, solar panels and led monitors for advertising that resembles the old billboards. Architecture can thus become a channel of communication that establish a dynamic relationship with the city.

WHAT - Program

TOTAL REPLACEMENT / DISCONTINUITY: The new functional program has completely replaced the original one.

The portico lost its original function a long time before it was purchased and refurbished, and therefore was left abandoned for several years. The commercial activities hosted in the nearby building evolved along the years and changed reflecting the evolution of the surrounding area and the whole neighbourhood. In the same way, the Castello ditch, together with the whole Navigli system, lost its importance in favour of others kind of mobility and it was covered to give space to the new road system and the new constructions that affected the street. It is with no surprise then that the original program was replaced with a brand new function. The refurbishment host a house and an architectural studio: the separation is clear but flexible due to translucent plastic curtains and mobile closets. On the second floor, a more private area is obtained again with a costume closet as partition that create a first room before the bedroom. The domestic space will be set aside for hosts once the new house above the roof will be completed. The new house will be fully independent from the rest of the building, with stairs that will provide a separated access. In the meanwhile the metallic frame emerging above the built house provide supports for the versatile overloads panels of the enclosure: solid infill, green portions, traditional segment in stone or technologically advanced monitors, with still or changing images.

WHO - Financing

TOTAL CONSERVATION / CONTINUITY: The investor is the property owner.

The portico has been purchased in 1999, after being abandoned for several years, and since then, it is property of the architect. The refurbishment is therefore completely financed by the owner.

HOW MUCH - Absolute Dimensions


PREVALENT CONSERVATION / CONTINUITY: The overall dimensions increase moderately with respect to the pre-existing surface.


BALANCE BETWEEN CONSERVATION AND REPLACEMENT: The overall dimensions are about twice the pre-existing volume.

The project take places entirely in the portico’s plot, without any expansion or invasion towards other plots or artifact. The adjacent building is left untouched.

HOW MUCH - Relative Dimensions

PREVALENT CONSERVATION / CONTINUITY: Pre-existing spaces are prevalent with respect to new spaces.

Due to the condition of ruin in which the building was encountered, the project can be considered as a heavy refurbishment. Despite of the great transformation proposed by the architect, the first phase did not cause a variation of volume and surface, since the house grew inside the original walls. The second phase, still on-going, envision a growth of volume: the new house on the roof will be characterised although by a volume which will be less than a half of the lower house.

HOW - Design Strategy STRUCTURE

BALANCE BETWEEN CONSERVATION AND REPLACEMENT: The supporting structure is composed in a balanced way by pre-existing structures and new structures.

The original walls of the portico are the starting point for the project of the new metal structure, which is carefully design to make it fade into the whole of the house: the structure is intersect not only by skylights, but also by large dormers and transparent glazings on the façade; the staircase is a compact macro-object of slender iron beams, not invasive in spite of the material, with glass steps. The terrace level of the second phase is now used as the base for the installation of photovoltaic systems, where the perimeter pergola represents the aluminium structure of the future house. As the project evolves, the internal staircase will connect the studio on the ground floor to the library and bedroom zone set aside for the guests. Then a second ramp, right above the existing one, will led to the new residence level.

HOW - Design Strategy MATERIAL

TOTAL REPLACEMENT / DISCONTINUITY: The materials chosen for the new intervention are completely different from the pre-existing ones.

The stated source of inspiration for the design of the structure and the choice of the material was Mies van der Rohe, and in fact the architect tirelessly invested time and passion in the technical development of each of the slender cruciform aluminium pillars and the light angle irons for easy transport, bolted into place at the site, which form the load-bering structure of the pergola-frame, with anodized finishing half in silver and half in gold, like the section of the iron structure, half galvanized and half tropicalized in a gold color. The iron structure rise from the ground to the top of the roof, leaning on the wall, o support the aluminium framework. The two structures are isolated from each other by means of sheath to prevent the thermocouple phenomenon between aluminium and iron.

HOW - Design Strategy IMAGE

BALANCE BETWEEN CONSERVATION AND REPLACEMENT: The new intervention balances elements of continuity and discontinuity with respect to existing structures.

As described before, Mies van der Rohe has been a clear inspiration for this project. The architect already had the possibility to develop the concept of a 21st century kit-house during the Venice Architecture Biennale in 2010 when the prototype of a structural module assembled in Marghera floated on the water at the Arsenale, where it had been towed by a tugboat along the Giudecca Canal and the Bacino di San Marco.