A network of skills

GST Appalti e Costruzioni was founded with the union of four large players in the construction industry in Tuscany and the country, convinced that joining together would be a driving force for development.

The member companies CMSA, Consorzio Stabile GST, Berni and Verde 21 optimized their existing flexible and efficient business model, leading to cooperation and the multiplication of skills and resources.

This resulted in one of the largest catalogues of services on the market, configured to meet the needs of any type of customer, whether public or private.

From infrastructure, to civil and industrial construction, to plants, recovery and restoration operations, energy efficiency and renewable energy production, design and construction of furnishings, GST Appalti e Costruzioni stands out for its executive reliability and ability to completely manage the project while strictly complying with the time frame.

The relationship with the customer is focused on a continuous interchange of information and goals, to stand behind the customer’s expectations and interests.


C.E.M. Srl: the company is specialized in reinforced concrete, masonry, excavation and earthmovingworks. Categories: OG1 VI, OG3 III BIS.

IES srl: the company is specialized in construction works and mechanical systems. Categories: OG1 IV e OG11 V.

MASI Srl: the company is specialized in electrical and mechanical systems. Categories: OG10 I, OS 30 III.

OLV Srl: the company is specialized in electrical and mechanical systems. Categories: OG10 I, OG11 II, OS28 II, OS30 III-BIS.

PEDERZANI IMPIANTI Srl: the company is specialized in electrical, mechanical and energy efficiencysystems. Categories: OG9 III-BIS, OG10 I, OG11 V, OS3 IV, OS22 II, OS28 V, OS30 III.

TIRRENA COSTRUZIONI GENERALI Srl: the company is specialized in construction works and infrastructure. It is part of the Fratelli Massai from Grosseto which holds different companies that manage bituminous conglomerate quarries and plants. Categories: OG1 III BIS, OG3 IV-BIS, OG 6 I, OG8 III.

ITALBUILD Srl: the company is specialized in construction works and infrastructures. Categories: OG1 VII, OG3 V, OG 6 IV-BIS, OG8 IV-BIS, OS1 III-BIS, OS6 III-BIS, OS7 IV, OS22 III-BIS, OS23 II, OS24 I.

CMSA was founded in December 1944 and since then operates in the design, construction, recovery and restoration, as well as maintenance of:

  • Civil, monumental, industrial, executive and residential buildings;
  • Hospital building;
  • School, university and research buildings;
  • Shopping centers;
  • Road works;
  • Airport and railway works;
  • Networks, gas pipelines, aqueducts, sewers, irrigation systems, public green areas;
  • Hydraulic and forestry arrangements: Waste treatment plants;
  • Land consolidation, special foundations;
  • Own real estate business.

CMSA own the following categories: OG1 VIII, OG2 VIII, OG3 V, OG 6 VIII, OG7 III-BIS, OG8 IV, OG11 V, OG12 VI, OS1 III-BIS, OS3 II, OS4 IV BIS, OS6 VII, OS7 IV-BIS, OS8 IV, OS14 II, OS21 V, OS22 II, OS23 I, OS24 II, OS26 II, OS28 III-BIS, OS29 I, OS30 III-BIS, OS18-A V.

Verde 21 Srl produces and markets photovoltaic and geothermal design generators.

BERNI srl designes, produces and markets   home furnishing.


We operate in the procurement and construction market – sharing the experience and skills of the partner companies – in order to turn ideas into projects and projects into sustainable works that are consistent with the customer’s expectations.


The ultimate goal that guides our choices and actions is to help redesign the urban environment to improve the quality of people’s lives. In order to succeed, we must respect the environment and health and safety.



The GST Appalti & Costruzioni Commercial Consortium is governed by a Board of Directors elected by the Assembly and is made up of the President and one member from each of the partner companies.

Di Nardo



Board Member


Board Member


Board Member