 | BKS SERVICE Per Haug | 980159450 | OSLO |
| BK TAKST OG EIENDOMS SERVICE AS | 897404672 | OSLO |
| BLAKSTAD HAFFNER AS | 913211529 | OSLO |
| BLIKKENSLAGER BREEN AS | 927965402 | OSLO |
| BLIKKENSLAGERMESTEREN ENTREPRENØR AS | 995455919 | OSLO |
| BLIKKENSLAGERMESTRENE HENRY HANSEN & SØNN AS | 912360997 | OSLO |
| BLOKK ARKITEKTER AS | 994293745 | OSLO |
| BMA HEISTEKNISK RÅDGIVNING AS | 974411709 | OSLO |
| BNK CONSULT AS | 930160938 | OSLO |
| BOGL NORGE AS | 924678380 | OSLO |
| BOIT AS | 914391768 | OSLO |
| BOKEMO AS | 931901877 | OSLO |
| BØLGEBLIKK ARKITEKTER AS | 939975012 | OSLO |
| BOLIGBYGGELAGET USBL | 950285680 | OSLO |
| BOLLINGER + GROHMANN INGENIØRER AS | 915298087 | OSLO |
| BORHAVEN ARKITEKTER AS | 913321677 | OSLO |
| BORO-BYGG A/S | 942587031 | OSLO |
| BORO-PROSJEKT AS | 942604106 | OSLO |
| BO WIIK BYGG AS | 998830028 | OSLO |
| BRA ARKITEKTER AS | 826490152 | OSLO |
| BRANDBU BYGGSERVICE AS | 890716512 | OSLO |
| BRANNKONSULT AS | 912679217 | OSLO |
| BRANN & VANNTEKNIKK AS | 915808026 | OSLO |
| BRAVIDA NORGE AS | 987582561 | OSLO |
| BRAX RØR AS | 922735905 | OSLO |
| BREKKE & STRAND AKUSTIKK AS | 916863071 | OSLO |
| BRIT SEJERSTED BØDTKER SIV ARK MNAL | 975966046 | OSLO |
| BRODIN AS | 982784875 | OSLO |
| Brødrene Dahl A/S | 945757280 | OSLO |
| BRØDRENE HAMMERSTAD AS | 974343320 | OSLO |
| BRØDRENE HANSEN GRAVESERVICE AS | 877021572 | OSLO |
| BRYN BYGG AS | 996558592 | OSLO |
| BTI KONSULT AS | 998052084 | OSLO |
| BUGGE & RAVN ARKITEKTER AS | 997682068 | OSLO |
| BUILT ARKITEKTER AS | 931668676 | OSLO |
| BUILTBY AS | 811863262 | OSLO |
| BUNDEBYGG AS | 962383149 | OSLO |
| BY AKUSTIKK AS | 995167808 | OSLO |
| BYE & DØHLEN VENTILASJON AS | 981132874 | OSLO |
| BYGG 1 OSLO AS | 987377593 | OSLO |
| BYGGESAKSRÅDGIVNING AS | 977545439 | OSLO |
| BYGGETEK AS | 928130959 | OSLO |
| BYGGINGENIØRENE AS | 931227327 | OSLO |
| BYGGIOSLO.NO AS | 999512720 | OSLO |
| BYGGKOMPANIET AS | 924831189 | OSLO |
| BYGG & MAL AS | 994841432 | OSLO |
| BYGGMESTER A. ØISANG AS | 812295802 | OSLO |
| BYGGMESTER CHRISTENSENS EFTF AS | 968703617 | OSLO |
| BYGGMESTER DYRNES AS | 917587957 | OSLO |
| BYGGMESTER LASSE DOKSRØD | 988029092 | OSLO |