Passivhaus VIDEIRA

Last modified by the author on 09/03/2015 - 18:58
  • Building Type : Isolated or semi-detached house
  • Construction Year : 2011
  • Delivery year : 2012
  • Address 1 - street : Coiro 36947 CANGAS DO MORRAZO - PONTEVEDRA - GALICIA, España
  • Climate zone : [Csb] Coastal Mediterranean - Mild with cool, dry summer.

  • Net Floor Area : 162 m2
  • Construction/refurbishment cost : 250 000 €
  • Number of Dwelling : 1 Dwelling
  • Cost/m2 : 1543.21 €/m2

Proposed by :

  • Primary energy need
    55.26 kWhpe/m2.year
    (Calculation method : )
Energy consumption
Economical buildingBuilding
< 50A
51 à 90B
91 à 150C
151 à 230D
231 à 330E
331 à 450F
> 450G
Energy-intensive building

It is a detached house designed under both the Passivhaus standard and bioclimatic criteria in order to achieve an highly energy efficient housing, with a nearly zero energy consumption. Furthermore bio-construction criteria are also followed, using both materials and structural systems that have low environmental impact.


At the beginning the project design tried both to recovery and to increase the existing house on the plot. Nevertheless due to its need of being repair and the high cost of the rehabilitation the house was demolished. But on the other hand the decision of keeping the design of the original volume was made due to no lose time with a new permission approval.


The house extension is solved with an additional compact volume attached to the existing one. Pointing the living room and the rooms towards the south and the garden. The new volume has a  flat greenroof and the elevations have different features (depending on their use and their guidance) looking for making a difference with the existing building, showing his evolution.


The main milestone of this work was the possibility of making a passive house.

See more details about this project

Data reliability



Contracting method

Other methods

Owner approach of sustainability

The architect, Mike Lehmhaus (from CASADOBE Architecture Studio), was contacted by the client to develop the project of the rehabilitation and the extension of his future home in 2008. The works of the Studio are guided forwards to the construction of buildings with: low energy demand, almost zero consumption and being respectful with the environment. Being one of the precursors of ”Passivhaus Standard” in Galicia. For this reason the Studio proposed the owner the developing of an Passivhaus. He accepted. Besides bioclimatic measures to take advantage of the solar gains, the use of materials and construction systems to achieve a low environmental impact was done.

Architectural description

It is a detached house located in the parish of Coiro, in the town of Cangas (Pontevedra - Galicia). The plot has an area of 714m² of which the house occupies an ground area of 117m². It has also: an open garage zone and some cobbled path to access both the garage and the house. The rest of the plot is a garden. The dwelling consists in two volumes. At the beginning it was intended to rehabilitate the existing building and to add a module made of wood. But when the work gets started, it was proved that would be cheaper to demolish and to build a new house rather than to preserve the existing one. Despite this, in order to avoid a delay in the work, the initial project was maintained. It means that both the look and the size of the demolished house were respected. The new rectangular two-storey volume was resolved with light frame wood and cellulose and a flat green roof with extensive vegetation. The interior is designed in order to meet the needs expressed by the builder family. The property, on the ground floor, has: an open room for the kitchen-dining-living room, two bedrooms, a bathroom, a laundry room and an outdoor terrace. Upstairs there is a master bedroom, a bathroom and another space prelude to the other ones, which is used as an office. Also on this floor there is an garret, which is used as an attic. The materials used include: wood, cellulose, wood fiber panels, viroc, thermo-clay bricks, EPDM membrane, linoleum, a vapour check and airtightness membrane. Moreover wood windows with triple glazing low-e glass and warm edge spacer. It also has a vegetal roof that improves the isolation therefore enhance energetic efficiency of the building and helps to improve the microclimate (dedusting, water retention, living space, temperature reduction, ...)

If you had to do it again?

If the option of demolishing the existing house had been considered from the beginning, the design of the new house would have been modified to suit better the customer needs.

A Blower Door Test would be done in the execution phase of the project so it is more accessible to resolve existing infiltrations.

With the first storm, the cover waterproofing showed an untraceable leakage. Therefore, the client decided to put a sloping cover with a direct drain. In future flat covers, the constructive solution must be simplified as well as to increase the control of the execution.

Placing the wood fiber panel in the sloping cover is fragile and needs to be covered sooner, immediately.

As expected, there was overheating in the living room and master bedroom. Unexpectedly in the attic. To resolve the external protection measures were taken, that could have been integrated from the outset.

Building users opinion

The building was finished in August 2012 and the clients moved into the house in September. Since then, and because inhabiting a house means to test it, there have been small improvements.
After the first year there are two significant figures which illustrate this experience: 21° C constant internal temperature throughout the year and 75% reduction in terms of electricity consumption per m² compared with the previous domicile.

Energy consumption

  • 55,26 kWhpe/m2.year
  • 112,39 kWhpe/m2.year
  • 46,17 kWhfe/m2.year

Envelope performance

  • 0,19 W.m-2.K-1
  • The entire thermal envelope was designed and built according to the “passivhaus” standard criteria.
    - LHD-brick and thermo-clay U: 0.19 W/(m²K)
    - Light Wood Framing U: 0.19 W/(m²K)
    -Windows Wood with triple glazing Ug: 0.6 W/(m²K)
    -Green roof U: 0.19 W/(m²K)
    -Tile roof U: 0.23 W/(m²K)
    -Floor U: 0.19 W/(m²K)

  • 1,02


    • Others
    • Individual electric boiler
    • Solar Thermal
    • Canadian well
    • Natural ventilation
    • Double flow heat exchanger
    • Canadian well
    • Solar Thermal
  • 80,00 %
  • Heating system:
    It has not got a traditional heating system. A biomass stove is installed in the living room and the house also has radiant mirrors in the bathrooms for extra input/contribution in case of necessity. The ventilation system is in charge of the heat distribution.

    Refrigeration system:
    No traditional refrigeration system is installed.

    Ventilation system:
    -Cross ventilation in all rooms. It gives advantage to natural and fast ventilation without energy consumption.
    -Mechanical monitored ventilation system with heat recovery and summer bypass. Air intake pre-treatment is done through a Canadian well (surface to air exchanger) which reduces the need for either post heating or cooling. Also with this ventilation system the air is filtered and the interior humidity levels are controlled.

    Hot water system
    -Solar Thermal Energy: This system is designed for the domestic hot water (DHW) production. It has an annually solar contribution of 80%. It has two high performance integrated solar collectors with a total area of 3,6m²; with an inclination of 31° south and a stratified accumulation deposit of 450 liters that is independent of the drinking water circuit. To solve problems of stagnation and overheating a drain-back system is used.
    -Electric water heater: to cover the remaining demand.

GHG emissions

  • 3,68 KgCO2/m2/year

  • 50,00 year(s)

Indoor Air quality

    Ventilation flow rates are achievable according to the Table 2.1. HS3-CTE. The ventilation system is mechanical with a heat recovery system. The ventilation is continuous at very low speed, which ensures an optimal air quality without creating any discomfort. The recovery system takes advantage of the 85% of the energy that comes from the interior hot air before being expelled. Its consumption is very low and its maintenance only requires the replacement of the filters located at both air outlets and in the entrance of the earth to air heat exchanger (canadian well).


    Lamina Intello


    Polígono Ibarrea s/n E-31800 Alsasua (NAVARRA) Tlf. 948 564 001 - Fax 948 564 230 - Email: [email protected];

    INTELLO®: Vapour check (and airtightness) membrane with wide range of variable diffusion resistance: In cold weather high protection from condensation (sd - value > 25 m), whilst in summery weather they have very high permeability (sd approx. 0.25 m) for back-diffusion.

    Membrane: Polyethylene copolymer
    Fleece: Polypropylene
    Water vapour resistance factor µ: 37.500
    Thickness: 0,2 mm
    sd-value: 0,25 m- 25 m variable
    Fire behaviour: E
    Temperature resistance: from -40 C until + 80 C
    Colour: white-transparent
    CE labeling (EN 13948)

    Workers have no awareness of the need of the membrane and its importance. It is difficult for them to follow the guidelines of the construction management.



    Polígono Ibarrea s/n E-31800 Alsasua (NAVARRA) Tlf. 948 564 001 - Fax 948 564 230 - Email: [email protected]

    Cellulose as insulation material is a recycled product from newspaper which is undergoing to a full process of grinding, shredding and treating with boric sales that cover the “flakes”, generating an effective protection against fire and parasites.
    It is applied with a machine that blows the product inside of the gaps. As thermal, acoustic and fire-fighting protective insulation, cellulose can be used in the filling of chambers decks, floors, dividing walls, facades, etc.

    Mechanical and physical characteristics:
    - Coefficient of thermal conductivity: 0,037 W/(m·K)
    - Settling: 4%
    -Ph: 7,7
    - Water vapour resistance factor: 1-2μ
    -Reaction Fire. Class B2
    -Specific-heat: 2100 J/(kg·K)
    -Mold growth: Level 10
    -Humidity: 10%
    -Energy Contained: 58 kWh/m²

    Heat recovery unit


    Zehnder Group Ibérica Indoor Climate, S.A. C/ Argenters, 7 Parque Tecnológico 08290 Cerdanyola del Vallés Barcelona Tlf. +34 902 106 140 Fax +34 902 090 163 - Email: [email protected]

    The Zehnder ComfoAir 350 ventilation units control both the intake and extract air of the ventilation system. Thanks to the control unit, easy to use, it is easy to adjust the quantity of air that is needed. All units are fitted with a filter as standard, fine and pollen filters can be retrofitted.
    -Comfort ventilation for duties up to 370 m³/h
    -Heat recovery with an efficiency of more than 90%
    -Low power consumption thanks to DC motors
    -Automatic 100% summer bypass
    -Frost protection function: efficient even at low temperatures
    -Quick, safe installation and servicing
    -Wireless remote control and filter replacement indicator
    -Geothermal heat exchanger control

    Good acceptance by all actors.

Construction and exploitation costs

  • 23,50
  • 250 000

Urban environment

The house is located in the parish of Coiro, a few kilometers from the town center of Cangas do Morrazo, in Galicia (north-west Spain) so it has all kinds of services. Although Coiro fundamentally and socially is an interior parish, on its coast is located the busiest beach of the town, Rodeira, because this is the closest beach from the village center. Furthermore this area is complemented by other two smaller an almost unknown beaches: Alemanes and Canaval. Coiro is located on the eastern edge of the municipal territory, on the border with Moaña. Inland, Coiro keeps marvellous natural corners, some of them declared Protected Natural Areas (as Carballeira of Coiro, which is a typical Atlantic forest that is plentiful of oaks, carballo in Galician, alders and birches). The Bouzo River completes a space where, as in all the rivers and streams of these lands, many mills, more or less, remains preserved. This is because some of them have been used until relatively recently time, as Fausto mill which has been restored so people can see how it works. Moreover in Coiro grow up important families that became part of the rural aristocracy, as Mondragón family, as well known as The Marquis of Santa Cruz de Rivadulla. It means that there are numerous luxurious country houses (pazos in Galician) and emblazoned buildings. Among this Pazos the most famous are A Retirosa and O Xistro. The church of San Salvador is also an interesting monument which highlights the disproportionate of its baroque tower. With regard to communications by road, there is the AP-9 (Atlantic Highway) that, through the Morrazo Corridor and the Rande Bridge, connects the Morrazo area with Vigo (the Galician biggest city); all the southern part of Galicia; the plateau and Portugal. One of the AP-9 branches is the PO-551, a provincial highway, which connects Cangas with Moaña. Another branch, the PO-315, connects Cangas with Bueu. Once there, in Bueu, you go to Pontevedra, the capital of the province, by a highway that passes nearby Marín. Moreover there are countless roads that connect the different neighborhoods that put together the municipality. Regarding to the public transportation, the neighborhood does not have this service. Although there are intercity buses that link Cangas with the neighboring towns. These buses also go directly to Pontevedra. Ship communications are well developed. The maritime terminal is just a few meters from the bus station. It is a good example of “intermodal station” because this is one of a few in Spain that combines both sea and ground transportation.

Land plot area

713,68 m2

Built-up area

18,00 %

Parking spaces

One double garage within the plot is constructed.

Building Environmental Quality

  • Building flexibility
  • indoor air quality and health
  • biodiversity
  • acoustics
  • comfort (visual, olfactive, thermal)
  • energy efficiency
  • renewable energies
  • integration in the land
  • products and materials

Building candidate in the category

Materiales de origen biológico

Materiales de origen biológico

Energías renovables

Energías renovables

Edificios de consumo nulo

Edificios de consumo nulo

Salud y Confort

Salud y Confort

Green Building Solutions Awards 2015

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Author of the page

Mike Lehmhaus


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Green Building Solutions Awards 2015