Limestones are generally vulnerable to various weathering effects, hence, protection and consolidation of them is necessary. Locally available limestones of Northern Cyprus have been used in both historical buildings dated back to the 16th century for conservation applications and new buildings mostly as a cladding material. However, certain decay patterns exist on these stones. In the current study, the service life of Cyprus stones was inspected. Alkoxysilane-based consolidation and protection treatments were applied on new quarried stones to enhance the stone properties and aged stones to conserve and protect the architectural heritage. Service life assessment was performed by applying accelerated aging tests on both new and aged stones before and after treatments. The treatments improved the physical, mechanical and durability properties of the stones in terms of unchanging the water vapor diffusion resistance factor, decreasing the porosity and the water absorption ratio, increasing the ultrasound pulse velocity, the compressive and the flexural strengths, and improving the resistance of the stones against wetting-drying, freeze-thaw, salt crystallization and SO2 vapour effects. The combination of consolidation and protection treatment (K2) was more efficient on the properties of the stones compared to only protection treatment (K1) due to the better penetration capacity, higher decreasing ratio of the porosity, and higher improvement of the physical, mechanical and durability properties. The treatments also improved the properties of the aged stones; thus, it may be inferred that treatment would benefit the conservation of historical buildings.