Conversion of agricultural warehouse to Senior Cohousing. Guimerà by Arqbag

Description of project by Arqbag

PROJECT

1. RE-PROGRAM

The project proposes the renovation of an agricultural warehouse, reprogrammed as a "senior" cohabitation. In order to accommodate two family units in the same building, the lifestyle of each individual family was studied, identifying their routines, concerns, and interests. This allowed us to plan and reorganize the spaces according to each use, specific to the degree of collectivization required at each moment. Individual, couple, collective and even neighborhood spaces were incorporated. 

The project is located in the urban center of Guimerà, in the region of Urgell (Catalonia). Streets, porches, arcades and stairs share the characteristic urban morphology which is of heritage interest.  Over its history, Guimerà has based its economy on agriculture, resulting in the distribution of a number of constructions that supported this activity scattered around the territory. The project proposes to refurbish one of these old buildings.

2. RE-SCALING

The preexisting structure consists of a large two-floor building that operated as a warehouse (P1) and a garage for agricultural machines (PB). Consequently, in addition to a change of use, the project had to resolve a change of scale. By creating a central earth block, composed of three large volumes, the space is reorganized, providing layouts on a domestic scale.

3. RE-COLLECTIVIZE

On the ground floor, in contact with the street and the orchard, the most common uses are contemplated: kitchen, living room, dining room, shared bathroom, and a large multi-purpose area. On the second floor the most private spaces are located: bedrooms and individual bathrooms. The program follows a "gradient of height privacy", where the two wood mezzanines can incorporate complementary uses depending on each moment.

4. RE-EQUIPPING

The central nucleus integrates the vertical circulations, services, and installations of the house: fireplace, stairs, bathrooms, kitchen, pantry, or machine room. All the facilities are derived from this central core, equipping each of the spaces.

5. RECOMFORT

The project considers the earth as a regulating material of the interior habitability. The large surface of the interior walls regulates the ambient humidity, provides high thermal inertia and balance, and contributes to the acoustic comfort between the different spaces.
On the other hand, the project proposes bioclimatic strategies such as solar gain, natural ventilation, or air stratification in order to reduce energy consumptions and improve the passive comfort conditions.

ECOLOGICAL APPROACH

Guimerà is characterized by a climate of extreme contrasts between summer and winter. From this perspective, it is very important that the architecture proposed responds to bioclimatic strategies that promote the thermal balance.

The central block, built with Compacted Earth Blocks (CEB), provides thermal inertia to the house and regulates the day-night temperature variations. In order to increase this inertia, a fireplace is located at the base of the central block, which transmits its heat to the earth walls. During the summer, the natural ventilation strategy facilitates the cooling of the central core's inertia, giving the space a feeling of constant comfort. 

In order to reduce energy loss, the envelope of the house is enclosed with a thermal panel. On the ground floor, the walls, built with the traditional stone wall construction system, already ensure sufficient thermal performance. 

For those moments when passive comfort cannot be guaranteed, there is an active system of radiant floor heating in the two main concrete floors. This system works through aerothermal equipment connected to the photovoltaic panels of the roof. The inertial tank works as a heating battery, storing hot water throughout the day.

The use of local earth, as well as the use of wood fiber insulation and other organic solutions for the refurbishment, contribute considerably to reducing the environmental impact.

TERRITORY

Understanding the situation of depopulation and rural abandonment that Guimerà is suffering from is fundamental to understand the essence of the project.  Returning to the original village where they grew up is the "end of life" project of the persons who will live in this cohousing. 

A return to their roots to live in a collective way in the last phase of life represents the end of a vital cycle. It is for this reason that the intervention had to be closely linked to the place, both from an aesthetic and emotional point of view. 

The aim of the project is to transform the industrial building without losing its original character. To achieve this the project aesthetic approach seeks to harness and optimize the existing structural systems, enhancing and highlighting signs of preexistence as reminiscent traces. 

The most precious heritage of Guimerà is the view of the village from the other side of the Corb river, where it can be seen how different local architecture is built from the riverbank to the highest point of the hill, with the constant of shared materiality in the stone being so typical of the place. The project reinforces this shared heritage. 
It is for this reason that the only extension of the preexisting structure is located exclusively on the ground floor. This addition, where the central block of CEB is located, has a light character with a structural system of wood and a façade completely permeable. This addition incorporates a green roof with native aromatic plants. 

The use of compacted earth blocks not only responds to a comfort strategy, but also reinforces the closing of the material cycle, emphasizing the " place " image from a tectonic point of view.

Promoting the local know-how economy

The desire of the users of this house to come back to their roots and revert the situation of rural depopulation in Guimerà, is in contrast to a passive and contemplative attitude. In fact the users assume an active role against rural depopulation. The manual skills of the different members that make-up the cohousing are considered a resource for the rest of the neighbors of the village. For this reason, the cohousing, in addition to responding to different degrees of privacy, defining private spaces, collective and communitarian spaces, also had to promote the support and growth of public spaces where the life of the users of this habitat would offer an example of sustainable and integrated life in the village. 

The proposal responds to this demand by means of the spatial distinction that forms the central block on the ground floor. This is the most communitarian part of the house and it is accessed from a delimited entrance which opens to the landscape thanks to the triangular shape of the pre-existence. This enhances an effect of increasing the presence on the backyard of the house where the communal orchard is located in relation to the street. 

The space on the other side of the central block, which is completely rectangular in plan, is conceived as a sequence of spaces with a workshop and product manufacturing use. This space connects the neighborhood orchard with the street. In that sense, the doors can be completely opened, creating a semi-public interior passage. This strategy offers the opportunity for local people and visitors to get involved into this project without disturbing or conditioning the other parts of the house.

BUILDING TECNOLOGY

In order to solve the scale transition from warehouse to cohousing, the multiplicity of use spaces, and the gradients of privacy, the project proposes the insertion of a central equipped block. This new element permits the reconfiguration of the pre-existing open space into multiple subspaces, which are distributed both in plan and in section. This central element constitutes at the same time an intermediate point of structural support for the floor slabs, reducing the large of the pre-existing beams to the half, and enabling the possibility of creating new intermediate slabs of wood. 

The nucleus is resolved by using a wall of compacted earth blocks (CEB). The decision to use this construction system was motivated by the difficulty of incorporating an extensive program in a geometrically complicated pre-existence. The block is distributed through 3 large units adapted to the program; it generates open spaces for storage or facilities, enclosed spaces with their own program, and passage spaces that interconnect or separate areas. At the same time, in order not to alter the original stone walls, the block concentrates all the installations of the cohousing. 

In terms of comfort, this large earth block provides a high hygroscopic property, which compensates the low capacity of existing stone walls to humidity regulation. In addition, it compensates part of the thermal inertia that is lost through the thermal insulation of the existing façades on its interior side.

The block units are designed as a "visible construction". The concept and construction of the walls is based on a 29x14x9cm "single-piece" module. 

For the elaboration of the compacted earth blocks, different samples have been made with aggregates of different granulometry of the site, in order to achieve the formulation appropriate to the requirements. Finally, the composition consists of gravel (12-20mm), natural sand with a high content of fines (0-5mm), clay, and NHL-5 hydraulic lime as a stabilizer. The earth walls have been built with lime mortar.