GENERAL INFORMATION

Renovated two storey building in Tuscany

Intervention year: 2025

Area of intervention: Research

Scope: Retrofit

Technology maturity level: Pilot project

Climate zone: Csa - Hot-summer Mediterranean climate

Greve in Chianti (Florence), Italy

Architect

CASA S.p.A.
Owner

Municipality of Greve in Chianti

This demo case consists of the innovative renovation of two twin residential buildings. One building is being upgraded with advanced INFINITE prefabricated facades, while the other uses traditional methods. This comparison aims to evaluate life cycle costs, life cycle assessments, installation time, user feedback, consumption, and performance. The prefabricated approach includes high-performance facade panels, a new lightweight wooden roof with integrated BIPV tiles, and prefabricated balconies with embedded ventilation units. The renovation also incorporates glass-glass colored BIPV panels, BIST cladding, and smart glazing windows. Extensive monitoring pre- and post-renovation provide detailed data on the efficiency and effectiveness of the prefabricated solutions.

Architect

CASA S.p.A.
Owner

Municipality of Greve in Chianti

Building sector

Residential

Building use

Apartment buildings

Heated floor area

318 m2

Facade area

425 m2

Building height

Low-rise building

Interstorey height

3.12

Existing building structure

Concrete

Existing wall stratigraphy

Plaster th. 0.15 1 W/mK Hollow brick th. 0.08 m 0.36 W/mK Not ventlated cavity th. 0.2 m Solid brick th. 0.12 m 0.7 W/mK

Total renovated facade surface (industrialised and not industrialised)

444.5

Percentage of renovated facade with industrialised approach

100%

Window to wall ratio

9.46%

U-value existing windows

n/a

U-value existing façade

1.32

U-value after renovation

0.18

Energy concept

The building moved from a decentralized energy concept to a centralized one. Initially, apartments had separate gas boilers for heating and Domestic Hot Water (DHW), with no cooling. Now, a centralized heat pump handles heating, DHW, and cooling. The new heat pump serves domestic hot water and supplies the ventilation machine systems for heating and cooling the apartments.

BEFORE RENOVATION

Technology solution sets	Type of system	Generation	Distribution
Heating system	Decentralised	Gas boiler	Radiators
Cooling system	n/a	n/a	n/a
Mechanical ventilation	n/a	n/a	n/a
Domestic hot water	Decentralised	Gas boiler	Water pipes

AFTER RENOVATION

Technology solution sets	Type of system	Generation	Distribution
Heating system	Centralised	Heat pump	Air ducts
Cooling system	Centralised	Heat pump	Air ducts
Mechanical ventilation	Decentralised	Ventilation unit	Air ducts
Domestic hot water	Centralised	Heat pump	Water pipes

Integrated technologies

The heat pump connects to the Energy & Fresh air kit, offering heating, cooling, and air renewal through ducts in the façade. BIPV kits on the façade and roof help to partially power the heat pump. Other features include smart windows with lamellas, sensors, and a BMS for complete control.

Smart windows

A PELLINI louvered shading system is integrated in the insulated glass unit for all windows. It covers living rooms, kitchens, bedrooms (east/west), bathrooms (south/north), and a north window for privacy. The system can be controlled manually or through a SENSE bar sensor, installed outside the window, that adjusts the louvers based on incident radiation.

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Mechanical ventilation

The ventilation machines are placed in the parapet of the prefabricated balconies: this setup makes ordinary and extraordinary maintenance easy. In fact, an integration of the machines into the wall, with accessibility from the inside, would have involved the demolition of part of the wall under the windows causing excessive disturbance to the users of the apartments.

The distribution plenums can be accessed from the balcony for cleaning the ducts. The air supply, extraction, and recirculation ducts are integrated into prefabricated facades and connect to air vents in individual rooms. Ducts pass through holes in the mullions of the wooden frame and are insulated by rock wool panels.

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BIPV

Glass-glass colored BIPV is installed on both the roof and facades of the building. The prefabricated panels re-roof two pitches with the panels. The east and west facades feature oxide red color BIPV to match the passive cladding, creating a unified look. These panels generate electricity for common loads and the ventilation units.

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BIST

The south elevation integrates the BIST technology, with oxide red matching the passive cladding and BIPV panels. The plumbing system for domestic hot water was excluded due to implementation issues and potential risks during building operation. Corrosion on the BIST panels led to their use being limited to passive integration. Passive modules from are installed in a plug & play mode, with production and installation off-site.

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Envelope technology

Prefabricated envelope technology

Panel in timber frame
Insulation in mineral wool th. 160 mm
100 kg/m3
λ = 0.035 W/m2K
Compensation layer: Glass wool 0.038 W/m2K 40 mm thick.
Wooden blocks for fixing brackets.
Steel brackets for supporting panels, fixed to the existing concrete structure

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External finishing

Rockwool cladding

Ventilated cavity

Yes

Main structure

Timber frame

Insulation

Mineral wool

Compensation layer

Glass wool

Anchoring element

Metal brackets

Joints

n/a

Tolerances

5 cm

Circularity

Embracing circularity in building renovation can lead to more sustainable and environmentally friendly outcomes. This means prioritizing the reuse and recycling of building materials, for example by implementing design strategies to facilitate the disassembly and reuse.

Ease of disassembly (system level)

n/a
Ease of reuse

n/a
Ease of recycling (component level)

n/a

Materials origin

n/a
Material use efficiency / Waste produced during production of the technol

n/a
Circularity certification

n/a

General Data

Max panel width

7.7 m

Max panel height

3.3 m

Panel Weight

0.5 - 0.6 kN/m2

Panel thickness

31 cm

Performance

We measure the effectiveness and efficiency of the building's prefabricated panels in terms of U-value, Acoustic resistance, Fire resistance, Seismic, Water/Air tightness.

U-value: 0.16 W/m2K

U-value

n/a

Acoustic resistance

n/a

Fire resistance

n/a

Seismic

n/a

Water/Air tightness

n/a

Certifications and tests

With certification and testing, the renovation project can achieve a higher level of quality, safety, and sustainability.

Simulation campaign

n/a

Tests

n/a

CE mark / type of certificate

n/a

Prefabricated roof technology

After the waterproof membrane insulation of the existing roof slab, a thermal insulation and wooden structure was installed to support the prefabricated roof panels and the new prefabricated wooden cornice for rainwater drainage.

Design and Installation

Construction process

The first phase of installations involved the installation of roof panels. After the waterproof membrane insulation of the existing roof slab, a thermal insulation and wooden structure was installed to support the prefabricated roof panels and the new prefabricated wooden cornice for rainwater drainage.

In the second phase, the prefabricated façade panels were installed. The anchoring systems were installed previously. In order to fix the anchors, the most external layer of bricks had to be punctually demolished in order to fix the anchoring systems to the existing concrete structure.

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Auxiliary elements (i.e. scaffolding)

Works on balconies

Replacement with prefabricated balconies

Works on roof

Replacement with new prefabricated roof

Interaction with the existing structure

n/a

Interaction with existing facilities

n/a

Level of disturbance

n/a

Installation time

180 m2/day

Methodology used for the audit and survey

Point cloud and laser scanner survey of the existing building. Verification on-site measurements. Existing load-bearing structure analysis. Survey thermographic camera

Digitalization of the pre-design phase

BIM model

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Digitalization of the design phase of the façade

BIM architectural model, 3D model (no BIM) for facade and roof production

Digital compatibility of data between design and manufacturing phase

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Prefabrication at component level

High

Prefabrication at whole-facade level

High

Transport typology to building site (any additional equipment needed)

Truck

Distance from the production site to the building site

390 km

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Performance and energy savings

Use stage

Use stage refers to the period during which the building is occupied and utilized after the renovation is completed. During the Use stage, several factors need to be considered: energy consumption, maintenance and repairs, indoor environmental quality, water usage, waste management, occupant behaviour.

Pre-renovation monitored data availability

n/a

Primary energy demand before renovation (total building consumption)

n/a

Energy demand for HEATING before renovation

n/a

Energy demand for COOLING before renovation

n/a

Energy consumption for HEATING before renovation

n/a

Energy consumption for COOLING before renovation

n/a

Energy consumption for domestic hot water before renovation

n/a

Thermal comfort before renovation

n/a

Primary energy demand after renovation (total building consumption)

n/a

Energy demand for HEATING after renovation

n/a

Energy demand for COOLING after renovation

n/a

Energy consumption for HEATING after renovation

n/a

Energy consumption for COOLING after renovation

n/a

Energy consumption for domestic hot water after renovation

n/a

Thermal comfort after renovation

n/a

Renewable energy production after renovation

n/a

Primary energy savings

n/a

LCC

Life Cycle Costing (LCC) can be used to evaluate the total cost of ownership of the building over its entire life cycle. This includes assessing the costs associated with the initial construction, operation, maintenance, and eventual disposal or recycling of materials.

Product / technology cost

n/a

Construction / installation costs

n/a

Maintenance

n/a

Operation

n/a

Replacement

n/a

End of life

n/a

Payback period

n/a

LCA

Life Cycle Assessment (LCA) can be used to evaluate the environmental impacts associated with the renovation process. LCA can help in understanding the environmental impacts of different building materials, evaluate the energy consumption and emissions associated with the construction activities, as well as the impacts of the building's usage and maintenance over its lifetime.

Technology impact

n/a

Product and construction stage (A1-A5)

n/a

Use stage (B1-B5)

n/a

Operational energy (B6)

n/a

End of life (C1-C4)

n/a

Benefits and loads beyond the system boundary (D)

n/a

Cultural and climatic aspects

Photovoltaic panels and smart windows encountered the most positive reactions among the interviewees. In the first case, this was because of the clear link with clean energy generation and cost saving; in the second case, there was quite some curiosity around the technology, although residents stressed that they liked having the possibility to keep windows open and to look outside.

People will be happy if the problems they perceive are solved or improved, if costs are reduced, if the new technologies are not complex. It must be considered that these are elderly people that have been living there for many years and are used to certain things and the way their life takes place. However, if there is a relation of trust and if residents understand the value and reason of INFINITE work, then they can be more open towards the biggest changes. In general, involving children of the older inhabitants and explaining them how to use the novel technologies is recommended, considering that parents often rely on their children for anything related to technology and technology appliances. Also, including the display of parameters interesting for residents, such as weather forecasts, can increase the interest in using BMS (building management system).

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