DESCRIPTION  "SOLAR HOUSE  BELOW ZERO CO2"

 

The eco-friendly semidetached house consists of  a concrete basement  and  a laminated wood structure rising above it. The house  is energy efficient enough to be an active home with no CO2 emissions.

The property has been built on the L.R. 14/2008 “Regulations for sustainable constructions", the DGR 1141/2009 and was in the regional call D.D.P.F. PROTECTED AREAS, KYOTO PROTOCOL, URBAN RENEWAL N. 102 / APP_08 OF 28/10/2009 "certified sustainable building Interventions".

It respects  the  Directive 2010/31/EU of the European Parliament and of the Council of 19 May 2010 on the energy performance (nearly zero energy buildings).

The building was conceived as a structure that:

Ø      respects the local building type (consisting of low semi- detached  houses  with  brick and / or plaster facing);

Ø      respects the environment since it is built with materials most of which are local and  natural;

Ø      respects the climate since it has zero CO2 emissions;

Ø      uses less  energy than the energy it produces;

Ø      reutilizes the rain water and  uses drinking water  only when it is indispensable;

Ø      respects the hydrological cycle  as the waterproof outer surface is minimal

Ø     the adjacent outdoor area  is built and operated with environmentally sustainable and/or almost natural criteria.

 

LOCATION

 

The building was built in the town centre of Mogliano Marche (MC) on an area ("B" completion of the current municipal PRG) where there were already  primary and secondary urban infrastructures , as well as the telephone line, methane and the public lighting. It was partly  realized  on an  area of the grounds  of a set of small masonry accessories that were not in any way  recoverable as they had been  built without foundations.

It is located on the top of a hilly ridge aligned east-west, it  is almost rectangular in  shape with the main facades oriented one to the south and one to the north. As far as the short sides are concerned,  one is oriented east and the other west.

The property area covers about one hectare from the ridge to the valley floor and is planted with olive trees with the soil permanently covered with grass and managed according to sustainable criteria.

 

STRUCTURE

 

The building consists of two units (distributed one to the east and the other west) identical and symmetrical with respect to a common partition oriented north-south. It is composed of :

  • a basement floor consisting of  a plastered support structure in reinforced concrete , the area is about 300 square meters (size about 30x10m) and it will be used as  garages, utility room, warehouse  and  farm tools storage;
  • a habitable ground floor, with a support structure made of laminated wood and  plaster facing, the surface area is  about 300 square meters (approximately 30x10m size) for the  two homes;
  • an attic mostly uninhabitable and used as a technical room and partly habitable for about  60 square meters, built with a load-bearing structure made of laminated wood and facing in plaster.

The ventilated pitched roof has  a laminated wood structure and  it is partly covered  with terracotta tiles and partly with a bitumen membrane with an innovative integrated photovoltaic solar plant 10,8kw.

 

EXTERNAL WALLS

 

The dwelling-bearing walls are made of beam  frames of 6x16cm in laminated pinewood  (from certified  sustainable forests) and  inside there are wood fiber panels from 160kg/mc (certified for green building), 16cm thick, all braced with a OSB  panel  that is  2,5cm thick and one internal that is 1,8cm thick for a total thickness of  20,3cm.

Outside the perimeter load-bearing wall  a thermal covering was built  using  wood fiber panels  of 160kg/mc (certified for green buildings) with a thickness of 12,0cm plus an environmentally friendly wood-magnesite panel  of 3,5cm protected  by a  breathable and waterproof thin layer of  plaster.

Inside the building on the perimeter load-bearing walls it was made a interspace for the plant engineering with a wood fiber panel  of 160kg/mc (certified for green building) 2,0cm thick and  a wood fiber panel of  50kg/mc (certified for green building) 5,0cm thick closed by an OSB panel 1,8cm and finally covered with a plaster board  of 1,25cm.

The total thickness of the perimeter of the bearing wall  is 46cm, of which 38,5cm  is made of  organic and natural insulating materials.

 The air-conditioned enclosure is isolated from the fortified concrete ceiling of the basement   by 28,0cm of insulation panels made of  xps (extruded polystyrene) where  all the plants were made to pass .

The floor between the ground floor and the first floor is made of bleached laminated wood beams and is enclosed by two layers of exposed bleached pinewood beads with a thickness of 2,0 + 2,0cm; in the habitable portion of the first floor were laid on the matchboard 10cm xps insulation panel where all the plants were made to pass.

On the ground  floor and the first floor of the house,  on the covering floor, above the insulation, a self-leveling radiant slab of dioxide of about  6 cm was created, and  finally a CSF oak parquet floor  of 1,5  was laid  in every room except in the bathrooms and in the kitchen where the floor is made of ceramic.

The covering floor is made of bleached laminated wood beams with a layer of exposed  bleached firwood beads  of the thickness of 2,0cm; above the  matchboard  there is a vapor barrier membrane (impermeable to both air and water)  wrapping the entire air-conditioned structure. Besides  24,0cm of wood fiber panels from 160kg/mc (certified for green building)were laid  plus a 6,0cm panel of mineral wool, the insulation has been closed at the top with an OSB of  1,2cm and a vapor control membrane. A ventilation chamber was made above the vapor barrier membrane, the chamber is of about 5,0cm and  closed at the top by an OSB  of 1,2cm coated with a bituminous sheath.

The structure has no thermal bridges and is so powerful from the point of view of energy consumption that it reduces  it in about 10Kw / sqm per year (expected  by the project) and the casing has a transmittance of approximately 27 hours that greatly reduces the  summer heat penetration within the air-conditioned interior. The air-conditioned enclosure has an excellent airtightness, the blower door test has achieved a performance of 0,31vol /h with a pressure difference between inside and outside of 50Pascal (Passivhaus in the air tightness standard in equal conditions must be <0,6vol /h).

 FIXTURES 

The windows are made of  wood-aluminum, with a thickness  of 93mm. They have a very high performance in terms of thermal properties with triple glazing (4b/12Ar/4/12Ar/b4) low emissivity with the following average values Ug = 0,70W/m2K and Uw (calculated) = 1,00W / m2K.The entrance doors are airtight and have a thermal insulation Ud=1,00W/m2K.  The installation of windows and doors was carefully prepared to ensure the absence of thermal bridges and air-tightness also through the use of XPS foam panels to insulate the shoulders, expansive seals, polyurethane foam and adhesive tapes for the air tightness. The thresholds of windows, French windows and doors are made in two parts (external and internal) with interposition of insulating material; this solution eliminates the thermal bridge which normally forms on the threshold.

 

 CONTROL OF SOLAR RADIATION 

In order to achieve a sustainable architectural project that succeeds in  optimizing active and passive solar contribution, the location, the orientation of the building and the presence of any shading were studied.

The transparent structures have been adequately screened from light and solar heat through the installation of aluminum shutters with adjustable slats until the total closure, which allow you to measure out the entry of light and shade as well as  offering a good visual screening.

The opaque structures on the south side, the  living area, have been shielded with a porch sized to maximize solar contribution in winter and  supply shade in the hot summer hours.

The opaque structures on the south side, the two sleeping areas, were screened each with a mulberry tree planted to provide shade in the hot summer hours (the tree forms a very large umbrella canopy) and in winter it maximizes solar supply since it is a deciduous tree and it loses its foliage .

 INSTALLATIONS 

The air exchange is guaranteed during the winter and summer by the controlled mechanical ventilation (CMV) with > 90% heat recovery, while in spring and autumn it can be achieved by natural ventilation (manual opening of windows north and south side). The controlled ventilation system with fresh air heat recovery  consists of a ventilation system that has been installed in  each apartment. It draws air from the service rooms (kitchen, bathrooms) and enters pre temperate and filtered outside air into living rooms and bedrooms. The outside air before entering the CMV is geothermally pre temperate passing on a radiator where  circulates the water from the geothermal probes that precool it  in summer and preheat it in winter. Each room is served by a geothermal well  which is about 30m deep with about 120ml of feeler installed; the temperature of the water inside them was found to be 15°C.

The air-conditioning of each dwelling is effected by means of a floor heating system powered by a heat pump, inverter, electric, (with COP = 3) air-water that uses the electrical energy produced by the photovoltaic system on the roof.

The innovative integrated photovoltaic made of amorphous silicon made on the roof more than  the electricity used by the building (for air conditioning, lighting, and appliances), resulting in a surplus of electricity that is poured on the network (active home). The private  consumption is maximized with the automatic activation of the electrical resistance present inside the accumulation heat of the heat pump producing water at a higher temperature.

The hot water is  100% ensured by the heat pump at low temperature with a 500 litre integrated storage tank.

The rainwater that falls on the roof is partially  recovered in a prestressed  reinforced concrete tub of about 21,000 litres located in the courtyard of the building and operated with an independent plant for feeding  the WC pans and for all those  uses which  are compatible with the water quality, including emergency irrigation of the garden  which has reduced water needs  since it is made with rustic extensive grassland and woody-native shrub species.

The appliances are energy efficient and WC pans have two buttons  to save water.

 

THE LAYOUNT OF THE BUILDING EXTERIOR 

The  building court has no waterproofed areas with the exception of the foundation protection sidewalks, the remaining area, about 1000m2, is  suitable for  vehicles and also for full lawn. The  portion suitable for vehicles of approximately 250m2 is   for access, parking,  manoeuvring of vehicles and the entrance to the garages placed at the basement. It was built with a ballast of gravel and gravel of light color to avoid the "heat island "which still maintains the permeability of the soil. The remainder, about 750m2, will be destined to rustic extensive lawn for recreational uses with predominance of grasses and legumes of spontaneous origin. The garden  does not need to be irrigated and has a low maintenance investment profile (low frequency of mowings per year,  no  weeding and fertilizing on a multi-year basis).The steepest slopes have been arranged with interventions of naturalistic engineering such as  live grates,  fences using debarked chestnut poles and native shrubs with low water needs. In the garden  stone walls were made  with local sandstone  and only on the border with the county road was built a reinforced concrete  retaining wall  on which a fence was placed.

 

Translated by Tiziana Dezi