A method of assembling a double-stranded target nucleic acid intended to have a predefined sequence, the method comprising: a) providing a population of single-stranded oligonucleotides having less than 200 nucleotides in length, wherein the plurality of single-stranded oligonucleotides are obtained by chemical synthesis, wherein the population of single-stranded oligonucleotides comprise a first set of oligonucleotides, together comprising at least a portion of a first strand of the double-stranded target nucleic acid, and a second set of oligonucleotides together comprising at least a portion of a second strand of the double-stranded target nucleic acid, wherein each oligonucleotide within the first set of oligonucleotides has a sequence region that is capable of hybridizing to at least one other oligonucleotide in the second set of oligonucleotides each of the oligonucleotides having an assembly region representing a portion of the target nucleic acid, wherein each assembly region has a sequence region that is capable of hybridizing to at least one other oligonucleotide in the population, b) providing a linear double-stranded polynucleotide, each terminus of the linear double-stranded polynucleotide having a sequence region that is capable of hybridizing to at least one oligonucleotide of the population, c) combining the population of single-stranded oligonucleotides with the linear double-stranded polynucleotide and a polymerase and dNTPs in a buffer to generate a reaction mixture, and d) subjecting the reaction mixture to cycling conditions that allow for (i) at least partial denaturation of the linear double-stranded polynucleotide to obtain single-stranded termini, (ii) hybridization of the population of single-stranded oligonucleotides to one another and to the single-stranded termini of the polynucleotide in a pre-determined order, (iii) polymerase-mediated extension of the free 3' ends of the hybridized oligonucleotides and the polynucleotide strands to generate a double-stranded non-covalently closed circularized assembly product comprising a linear arrangement of assembly regions, and (iv) amplification of the double-stranded circularized assembly product to generate an amplified double-stranded target nucleic acid intended to have a predefined sequence. a) providing a population of single-stranded oligonucleotides having less than 200 nucleotides in length, wherein the plurality of single-stranded oligonucleotides are obtained by chemical synthesis, wherein the population of single-stranded oligonucleotides comprise a first set of oligonucleotides, together comprising at least a portion of a first strand of the double-stranded target nucleic acid, and a second set of oligonucleotides together comprising at least a portion of a second strand of the double-stranded target nucleic acid, wherein each oligonucleotide within the first set of oligonucleotides has a sequence region that is capable of hybridizing to at least one other oligonucleotide in the second set of oligonucleotides each of the oligonucleotides having an assembly region representing a portion of the target nucleic acid, wherein each assembly region has a sequence region that is capable of hybridizing to at least one other oligonucleotide in the population, wherein the population of single-stranded oligonucleotides comprise a first set of oligonucleotides, together comprising at least a portion of a first strand of the double-stranded target nucleic acid, and a second set of oligonucleotides together comprising at least a portion of a second strand of the double-stranded target nucleic acid, wherein each oligonucleotide within the first set of oligonucleotides has a sequence region that is capable of hybridizing to at least one other oligonucleotide in the second set of oligonucleotides each of the oligonucleotides having an assembly region representing a portion of the target nucleic acid, wherein each assembly region has a sequence region that is capable of hybridizing to at least one other oligonucleotide in the population, b) providing a linear double-stranded polynucleotide, each terminus of the linear double-stranded polynucleotide having a sequence region that is capable of hybridizing to at least one oligonucleotide of the population, c) combining the population of single-stranded oligonucleotides with the linear double-stranded polynucleotide and a polymerase and dNTPs in a buffer to generate a reaction mixture, and d) subjecting the reaction mixture to cycling conditions that allow for (i) at least partial denaturation of the linear double-stranded polynucleotide to obtain single-stranded termini, (ii) hybridization of the population of single-stranded oligonucleotides to one another and to the single-stranded termini of the polynucleotide in a pre-determined order, (iii) polymerase-mediated extension of the free 3' ends of the hybridized oligonucleotides and the polynucleotide strands to generate a double-stranded non-covalently closed circularized assembly product comprising a linear arrangement of assembly regions, and (i) at least partial denaturation of the linear double-stranded polynucleotide to obtain single-stranded termini, (ii) hybridization of the population of single-stranded oligonucleotides to one another and to the single-stranded termini of the polynucleotide in a pre-determined order, (iii) polymerase-mediated extension of the free 3' ends of the hybridized oligonucleotides and the polynucleotide strands to generate a double-stranded non-covalently closed circularized assembly product comprising a linear arrangement of assembly regions, and