Selected among the top 10 timber projects of 2021

 

The Slow Studio House in Monte el Pardo project has been selected as one of the Best timber architecture projects of 2021 by the Association for Research of the Wood Industries (AITIM).

The jury’s decision highlighted the quality of the project’s sustainable consciousness beyond the presence of wood:

“Two-story dwelling with independent access on two levels to allow for independent use for programmatic reasons.

Architectural values: an interesting contemporary typology where wood stands out over its conventionality, both where it is present and in its interstitial details.

Complexity of the timber solution: classic but prefabricated light-frame structure.

Sustainability: in addition to the use of wood, the house is meticulously studied from a bioclimatic and thermal conditioning perspective using renewable energies. The study of SDG compliance is exhaustive and the sustainability report is frankly interesting.”

The award required the submission of two specific reports regarding the presence of wood and sustainability objectives.

 

To read the AITIM publication: AITIM timber awards publication

To view the project on our website: House in Monte el Pardo

 

 

TIMBER PRESENCE REPORT

Regarding the presence of wood, Slow Studio highlights the fact that the house is semi-buried, opting for a system of concrete block load-bearing walls that function as both the foundation and a thermal inertia wall.

This ground floor base supports the weight of a semi-prefabricated light-frame structure made of spruce wood on the first floor.

Thus, a perimeter beam acting as a frame is placed on the concrete block wall, along with a sill plate where the timber beams—14 cm wide by 28 cm deep—rest, spanning maximum lengths of 5.6 m.

From here, the light-frame floor slabs are supported, completed on the upper side with a 2 cm layer of sand that improves the acoustic performance and thermal inertia of the assembly.

The flooring finish on the first floor consists of wooden battens and slats. Overall, the floor slab is resolved with a total thickness of 10 cm.

The first-floor facades are built with the same light-frame structure—a ‘Balloon-Frame’ system—which arrives prefabricated at the site by the national company Arquima and is installed using a crane truck in just 2 days.

 

 

The facade structure is composed of a frame of 14-centimeter-thick laminated pine wood slats, protected on its exterior face by screwed OSB panels and on its interior face by gypsum fiber panels.

Insulation is applied from the outside over the OSB board using an ETICS system of stratified pine wood fiber with low thermal conductivity and vapor permeability, reducing the risk of condensation and dampness.

These pre-formed wall sections arrive at the site with a pre-planned structure of subframes where the project’s various doors and windows will be placed. All window joinery is carried out in natural wood, sourced from the national company Carinbisa to minimize the carbon footprint derived from transport.

The doors are made of spruce; the interior ones are stabilized by a laminate core to prevent warping, and the exterior ones—both the entrance and the sliding door—are made of solid spruce with three-centimeter tongue-and-groove planks to absorb expansion.

 

 

On the first floor, the roof structure is supported by beams of the same dimensions as the lower floor slab (14 cm x 28 cm). This structure is left exposed and untreated, evidencing its unidirectional arrangement and the heterogeneity of its knots, recessed at the junction with the facade to highlight the impact of the depth and the commitment to this demanding structural material.

The roof is resolved with a 23 cm thick slab, also using OSB panels and mineral wool panel insulation. These OSB composite panels are developed in the factory entirely in accordance with the demand for ecological organic materials, using resin as a binder to fix the strands.

The mineral wool is, in turn, manufactured with recycled and natural raw materials, bound with a plant-based binder that is once again free of formaldehydes, phenols, and acrylics.

Furthermore, the presence of wood in the project goes further, being used in the finishes, always with the intention of leaving it exposed to add warmth to the interior environment. The kitchen countertop is resolved with a combination of handmade terracotta pieces, except for the food preparation area, which is finished with a piece of natural oak wood treated with wax. The bathrooms are custom-made with masonry walls clad in clay and natural oak surfaces.”

 

 

SUSTAINABILITY REPORT AND COMPLIANCE WITH THE SUSTAINABLE DEVELOPMENT GOALS

Regarding the sustainability report, Slow Studio highlighted the bioclimatic design of the project and justified compliance with Sustainable Development Goals 3, 7, 11, 12, and 13:

 

BIOCLIMATIC DESIGN

As it is a compact house distributed over two floors, we must find a way to guarantee good lighting, sunlight, and ventilation in all rooms, which are always located on the south orientation and where cross ventilation is enhanced thanks to two courtyards, one on the north side and another on the south side of the house.

The south courtyard of the house is key to ensuring good natural ventilation without incurring energy losses. It is a double-height courtyard with a south-facing facade and a glazed roof that can be opened or closed depending on the season.

In winter, the glazing remains closed, achieving a greenhouse effect that preheats the natural outdoor air. As it is a double-height courtyard, we take into account that the stratification of hot air will move it towards the upper part, from where we introduce it into the house via CO2 sensors that activate fans located in the bathrooms. These absorb the air and renew it whenever the house is occupied.

In summer, the glazing opens completely and ventilation is carried out through a Canadian well, which is a tube approximately 30 meters long that runs under the house at a depth of one and a half meters, managing to introduce air into the house at a temperature of between 15 and 20 degrees during the warmest months of the year.

Additionally, in summer, it is possible to dampen the floor of the south greenhouse courtyard, which is made of porous paving and contributes to improving the thermal sensation of coolness.

As we have excellent solar gain with a clear south orientation of the main facade, it is designed with large glazed windows that allow us to capture radiation or protect ourselves from the sun depending on the season. Furthermore, the fact that it is a longitudinal house allows us to take advantage of the north facade to generate cross ventilation in all rooms on the upper floor. On the lower floor, which is semi-buried, ventilation is guaranteed thanks to the courtyard on the north facade.

In this way, we guarantee a comfort temperature for most of the year with passive strategies and by reducing energy consumption, without the need to resort to complex forced mechanical ventilation systems with heat recovery that alter the natural quality of the air in the natural environment where we are located.

Even so, the energy demand study indicates that due to being located in a cold climate zone and at a certain altitude, we have a high heat demand in winter and in certain weeks of the year a heating system might be necessary, so a heating installation using water radiators is prepared, which can easily provide the remaining energy demand during the coldest days of the year. Additionally, a wood stove purchased second-hand by the clients themselves is installed, perfect for demand peaks thanks to its power and its operation using a renewable energy source such as biomass.

 

 

COMPLIANCE WITH THE UN SUSTAINABLE DEVELOPMENT GOALS

With less than ten years until the 2030 deadline, the need for a much deeper, faster, and more ambitious response to meet the so-called Sustainable Development Goals is evident, generating a social and economic transformation that puts people and the planet at the center this time. The construction sector has a strong impact on global carbon emissions, but architecture also has the power to shape the customs and ways of living of different communities.

 

GOAL NUMBER 3: Health and well-being

Following the COVID-19 pandemic, the need for greater awareness and regulation regarding healthy indoor environments has become clear, as data shows that we spend an average of 90% of our time in indoor spaces.

In the house in the Sierra de Madrid, indoor air quality is guaranteed thanks to continuous air renewal, which in summer is carried out through a Canadian well system running under the house’s foundations that buffers the air temperature and introduces it fresh into the interior, and in winter, through a greenhouse courtyard that preheats the air naturally, in both cases without altering its humidity and health conditions.

It is important for air to circulate under normal conditions, that is, without the need to pass it through complex machines or filters, which not only alter its ionization quality but could also add harmful agents if the ducts are not properly maintained or are made with heat-sensitive plastics.

Furthermore, the project not only considers air renewal but also the quality of the indoor environment itself, avoiding all types of finishing products containing toxins that are emitted into the indoor air as volatile organic compounds (VOCs), which diminish its quality. Even in small amounts, as it is a continuous and long-term emission, it generates a bioaccumulation effect in the organisms of the people and animals inhabiting the space.

All types of varnishes, glues, and paints are avoided throughout the house. The first-floor facades are protected on their interior face by gypsum fiber panels composed of recycled paper, gypsum, and water, both free of glues.

The interior finish unifies the ground floor and the first floor and is composed of a layer of about 3 mm of clay in a grayish tone. Clay is a natural material with multiple properties, including the ability to absorb odors and high hygroscopicity—a quality that allows it to regulate humidity naturally, absorbing or releasing water vapor depending on the indoor environment conditions and maintaining the average relative humidity between 40-60% according to health reference recommendations.

On the other hand, there is no better well-being than ensuring a good building envelope that guarantees thermal comfort. Therefore, insulating the entire house from the outside allows us to eliminate thermal bridges throughout the envelope and improve comfort thanks to natural temperature gain on the south-oriented facades.

Another aspect to consider regarding the health of the indoor environment is the presence of electric fields that may interfere with the well-being of users, especially during nighttime hours when the body takes the opportunity to regenerate.

Thus, the electrical installation is carried out in a star configuration and with halogen-free cabling. Additionally, precautions are taken to avoid running cables in any long-stay areas such as bed headboards, and bioswitch devices are installed in each of the lines carrying electricity to the bedrooms with the aim of interrupting the supply to them during nighttime rest hours, eliminating any type of electric field.

 

 

GOAL NUMBER 7. Affordable and clean energy

Once the energy demand of the house has been reduced to the maximum, for the low energy contribution required, the use of affordable and non-polluting energies is prioritized. A commitment is made to two green energy sources. Firstly, an electrical connection to the grid is carried out through a supply of renewable energy production and consumption.

Additionally, we have a biomass stove that will be used on the coldest days of the year to heat the living areas. Biomass, despite not being free of CO2 emissions during its combustion process, is considered a zero-emission energy because the tree has previously absorbed the same amount of CO2 during its growth process.

 

GOAL NUMBER 11. Sustainable cities and communities

The impact of architecture is most evident in cities, which house more than half of the world’s population and are in constant growth.

The house in the Sierra de Madrid is located within the Madrid Metropolitan Area, a region that, together with the Barcelona Metropolitan Area, leads in urban development and mobility policies. From the restricted vehicle access project known as Madrid Central to proposing the implementation of a low emission zone (ZBE) previously applied in the BCN Ring Roads, the MMA is moving towards a more sustainable and consequently egalitarian community.

These are policies in favor of generating sustainable mobility that replace the dual model of the city as center-periphery to be understood as a city of hubs where it is not necessary to travel daily to have access to multiple commercial, cultural, or work and leisure services.

An integrative conception of urban centers with suburban growth is proposed, promoting clean and public transport, while promoting policies for the implementation of local services for the creation of more self-sufficient and resilient municipalities within a network inevitably interconnected with the city.

 

GOAL NUMBER 12. Responsible consumption and production

Much is said about carbon emissions and consumption throughout the useful life of buildings, but we often neglect that practically the same percentage, and even a much higher one in the case of waste generation, originates throughout the production chain of construction materials.

That is why we must pay special attention to the life cycle of these elements from the perspective of the circular economy, opting not only for natural and renewable materials like wood, but also construction systems that in turn facilitate their disassembly and reuse. Thus, we will stop distinguishing between renewable or non-renewable, understanding materials as permanent—an area in which prefabrication becomes our greatest ally.

In the case of the house in the Sierra de Madrid, we opted for a prefabricated “Balloon Frame” system based on spruce wood with PEFC sustainable management and chain of custody certification. Its pre-formation in the workshop allows for more precise resolution of construction details, thus avoiding thermal bridges and increasing the building’s energy efficiency. Furthermore, it grants greater architectural flexibility from the project design phase to possible changes of use due to its modular conception, which facilitates the adaptation of the building to new realities or program changes, preventing the building from becoming obsolete.

The concrete plinth on which this system is placed is made of concrete blocks, which have a smaller footprint than in-situ concrete and allow for subsequent reuse—after a crushing process—as fill for land or foundations, largely avoiding demolition waste. Similarly, wood fiber panels are used as insulation, a natural material that also takes into account health and indoor air quality criteria in contrast to other insulation products conventionally used.

Finally, an 8,000-liter rainwater recovery tank is installed to store rainwater for use in cleaning and toilets, with the aim of improving water resource management.

 

 

GOAL NUMBER 13. Climate action

This house in Monte el Pardo makes evident the commitment of a sustainable architecture firm together with the client and developer to opt for a passive house, denoting the awareness of all project participants to adopt urgent measures to combat climate change and its effects.

Building a zero-energy house should be taken for granted for any new construction project. We are carrying out an NZEB building (Nearly-Zero Energy Building) that minimizes energy demand through bioclimatic architecture strategies such as solar gain and protection, the use of thermal inertia, guaranteeing airtightness, and increasing insulation. From here, we cover the remaining demand through renewable energies and achieve a zero or nearly-zero consumption passive house.

However, what is still not so widely accepted by the market nor contemplated in construction regulations is ensuring that this house has a zero ecological footprint and that the indoor environment contributes to improving the well-being and health of people. That is, pursuing the objectives of NZIB buildings (Nearly-Zero Impact Building), which go a step further, paying special attention to the impact of materials, the life cycle, the built environment, biodiversity, or water management.

The price of natural materials and finishes is always higher, and as designers, it is a constant struggle to achieve the balance between project viability and the rigorous application of solutions that prioritize ecology and health with zero impact.
There is a long way to go, and probably one of the paths involves demanding more conscious regulations that take into account the impact of construction materials on the environment and people.

For the moment, carrying out these types of projects that not only achieve zero energy consumption but also reduce carbon emissions throughout the project’s life cycle and guarantee the health of the occupants falls on the joint effort of designers along with developers and builders committed to a conscious architecture that prioritizes quality of life and respect for the environment above all else.”