Abstract We present an extragalactic survey using observations from the Atacama Large Millimeter/submillimeter Array (ALMA) to characterize galaxy populations up to z = 0.35: the Valparaíso ALMA Line Emission Survey (VALES). We use ALMA Band-3 CO(1–0) observations to study the molecular gas content in a sample of 67 dusty normal star-forming galaxies selected from the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS). We have spectrally detected 49 galaxies at >5σ significance and 12 others are seen at low significance in stacked spectra. CO luminosities are in the range of (0.03–1.31) × 1010 K km s−1 pc2, equivalent to $\log ({{M}_{gas}/\mathrm{M}_{{\odot }}}) =8.9 \text{--} 10.9$ assuming an αCO = 4.6 (K km s−1 pc2)−1, which perfectly complements the parameter space previously explored with local and high-z normal galaxies. We compute the optical to CO size ratio for 21 galaxies resolved by ALMA at ∼3.5 arcsec resolution (6.5 kpc), finding that the molecular gas is on average ∼ 0.6 times more compact than the stellar component. We obtain a global Schmidt–Kennicutt relation, given by $\log \Sigma _{\rm SFR}/({\rm M_{{\odot }} \,yr^{-1}\,kpc^{-2}}) =(1.26 \pm 0.02) \times \, \log \Sigma _{{M}_{H2}}/({\rm M_{{\odot }}\,pc^{-2}}) - (3.6 \pm 0.2)$ . We find a significant fraction of galaxies lying at ‘intermediate efficiencies’ between a long-standing mode of star formation activity and a starburst, specially at L IR = 1011–12 L⊙. Combining our observations with data taken from the literature, we propose that star formation efficiencies can be parametrized by $\log \,{{\rm SFR/}{M}_{H_2}} = 0.19 \times \,{\rm (\log \,{L_{IR}} - 11.45)}-8.26- 0.41 \times \arctan -4.84\,(\log {{L}_{IR}}-11.45) $ . Within the redshift range we explore (z < 0.35), we identify a rapid increase of the gas content as a function of redshift.