Low energy villa in Le Sieci - Pontassieve - Florence
Architectural design, Energy design, Direction
Client: private (Florence)
Cost: € 375.000,00
2006-2011
Short description
The projet consists in a low-energy semi-detached house placed in a
very small sized triangular sloping plot. The plot is located in a hilly area
of landscape value, slightly urbanized, named Le Sieci near Florence.
The area consists of a part, free from vegetation, and a part with a
forest of conifers and hardwoods. The building contains two
independent apartments, each equipped with an individual entrance,
a panoramic view over the valley to the northwest and an access to
the garden to the south, where the plot widens towards the forest
property. The strong constraints of the site determined the functional
organization and volume, defined by three boxes stacked and
staggered.
Low-energy and well-being
The proposed internal layout, and openings, were affected by the
environmental performances that have a greater impact on
psychological well-being:
- Hygrothermal comfort in summer and winter
- Indoor air quality
- Natural lighting
- Enjoyment of the landscape
The size of the openings takes into account the use of space,
increasing daylighting in day rooms. The summer sun protection of
windows required a special study in order to minimize the need for
mobile screens (blinds and curtains), especially in living areas, which
requires the persistence of the view. The preference was for
permanent shielding (overhangs and shelters) that allow the winter
radiation for passive solar gain, and simultaneously provide effective
protection from the summer sun.
Indoor air quality is increased by the openings placed on the four
cardinal points and by air extractor located in toilets, that allow a
reliable and effective natural ventilation.
The roof is partly flat, with terraces for the use and enjoyment of the
landscape and with a''green roof'' that provides high thermal inertia
reducing heat island effect, as well as an outdoor space to the attic;
the roof is also sloping as a support for the architectural integration of
solar thermal panels and part of photovoltaics.
The building reaches the energy class A with a estimated consumption
of 34.43 kWh/sqm per year.
Sustainable and Easy to do
The energy design has been set on the principle of availability of
materials, simple design of technical systems and technical solutions,
as well as easy maintenance. Therefore, the focus was primarily on a
high performance envelope, leaving a secondary role to the plants
and avoiding the high-tech. The winter thermal behavior, the acoustic
behavior and the summer massive behavior of envelope has been
maximized, preferring ''damp''solutions the know-how is widespread
among construction workers in Tuscany. The innovation lies in the
choice of simple technologies such as hollow bricks, for walls, and
reinforced concrete lightened with polystyrene blocks, for floors, which
alone provide the required transmittances. The thermal bridges of
beams and pillars have been avoided from the design of envelope
solution, and the minimum transmittances of law greatly improved with
the addition of insulation:
- polyurethane panels in the floors, for its durability, rigidity,
breathability;
- glass wool in the walls, for its characteristics of high breathability
and sustainability (with a certified product processing waste glass and
formaldehyde-free); glass wool was placed inside the wall that ensures
effective protection and durability of the insulation.
Finishes are planned with low-maintenance materials, such as
aluminum high-energy performance frames and stoneware porcelain
external paving, with EPD environmental certification; Other finishes
are low-tech and low-cost solutions, such as lime plaster, highly
breathable, or ''kilometer zero'', such as stone walls, made with stones
from the nearby fields.
The system of plants, very easy to do, consists of a condensing gas
boiler and low temperature radiant floor panels. During the summer
the radiant floor panels work with fresh water, whose temperature is
lowered by heat exchanger using thermal gap of rainwater stored in
the underground tank.
The wood and its necessary maintenance ensures food for the
fireplaces thath actively contribute to the reduction of energy
consumption.
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