Jim Hollingsworth & Son construct extensions for domestic and commercial clients in Northern Ireland. We take care of your entire project, from the groundworks through to the completed extension.Jim Hollingsworth & Son construct extensions for domestic and commercial clients in Northern Ireland. We take care of your entire project, from the groundworks through to the completed extension.We cover all aspects of your extension, including: Foundations Brickwork Roofing Electrics Plumbing PlasteringExtensions you can rely onYou can rely on the extensions we build for you. With much of our business coming through word of mouth recommendation, you know you're in good handsWhen it comes to a new build there's a lot to take into consideration. From the groundworks to the roofing, you need a building company that can get things done efficiently and to a high standard of workmanship. That's exactly what you'll get with usIf you're looking to undertake a new build project in Northern Irelan.